diff --git a/src/accessor/grib_accessor.h b/src/accessor/grib_accessor.h
index 3a9578127..100cf8171 100644
--- a/src/accessor/grib_accessor.h
+++ b/src/accessor/grib_accessor.h
@@ -78,19 +78,19 @@ public:
 
 public:
     // TODO(maee): make private
-    grib_context* context_;
-    const char* name_;       /** < name of the accessor */
-    const char* class_name_; /** < name of the class (Artifact from C version of ecCodes) */
-    const char* name_space_; /** < namespace to which the accessor belongs */
-    grib_handle* h_;
-    grib_action* creator_;    /** < action that created the accessor */
-    long length_;             /** < byte length of the accessor */
-    long offset_;             /** < offset of the data in the buffer */
-    grib_section* parent_;    /** < section to which the accessor is attached */
-    grib_accessor* next_;     /** < next accessor in list */
-    grib_accessor* previous_; /** < next accessor in list */
-    unsigned long flags_;     /** < Various flags */
-    grib_section* sub_section_;
+    grib_context* context_ = nullptr;
+    const char* name_ = nullptr;       /** < name of the accessor */
+    const char* class_name_ = nullptr; /** < name of the class (Artifact from C version of ecCodes) */
+    const char* name_space_ = nullptr; /** < namespace to which the accessor belongs */
+    grib_handle* h_ = nullptr;
+    grib_action* creator_ = nullptr;    /** < action that created the accessor */
+    long length_ = 0;             /** < byte length of the accessor */
+    long offset_ = 0;             /** < offset of the data in the buffer */
+    grib_section* parent_ = nullptr;    /** < section to which the accessor is attached */
+    grib_accessor* next_ = nullptr;     /** < next accessor in list */
+    grib_accessor* previous_ = nullptr; /** < next accessor in list */
+    unsigned long flags_ = 0;     /** < Various flags */
+    grib_section* sub_section_ = nullptr;
 
     const char* all_names_[MAX_ACCESSOR_NAMES] = {
         0,
@@ -98,14 +98,14 @@ public:
     const char* all_name_spaces_[MAX_ACCESSOR_NAMES] = {
         0,
     }; /** < namespace to which the accessor belongs */
-    int dirty_;
+    int dirty_ = 0;
 
-    grib_accessor* same_;        /** < accessors with the same name */
-    long loop_;                  /** < used in lists */
-    grib_virtual_value* vvalue_; /** < virtual value used when transient flag on **/
-    const char* set_;
+    grib_accessor* same_ = nullptr;        /** < accessors with the same name */
+    long loop_ = 0;                  /** < used in lists */
+    grib_virtual_value* vvalue_ = nullptr; /** < virtual value used when transient flag on **/
+    const char* set_ = nullptr;
     grib_accessor* attributes_[MAX_ACCESSOR_ATTRIBUTES] = {
         0,
     }; /** < attributes are accessors */
-    grib_accessor* parent_as_attribute_;
+    grib_accessor* parent_as_attribute_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_abstract_long_vector.h b/src/accessor/grib_accessor_class_abstract_long_vector.h
index d9946f802..e667b5292 100644
--- a/src/accessor/grib_accessor_class_abstract_long_vector.h
+++ b/src/accessor/grib_accessor_class_abstract_long_vector.h
@@ -21,7 +21,7 @@ public:
 
 public:
     // TODO(maee): make private
-    long* v_;
-    long pack_index_;
-    int number_of_elements_;
+    long* v_ = nullptr;
+    long pack_index_ = 0;
+    int number_of_elements_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_abstract_vector.h b/src/accessor/grib_accessor_class_abstract_vector.h
index 408a58f46..9f070981e 100644
--- a/src/accessor/grib_accessor_class_abstract_vector.h
+++ b/src/accessor/grib_accessor_class_abstract_vector.h
@@ -21,6 +21,6 @@ public:
 
 public:
     // TODO(maee): make private
-    double* v_;
-    int number_of_elements_;
+    double* v_ = nullptr;
+    int number_of_elements_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_bit.h b/src/accessor/grib_accessor_class_bit.h
index ec0fed2c1..58e6f8719 100644
--- a/src/accessor/grib_accessor_class_bit.h
+++ b/src/accessor/grib_accessor_class_bit.h
@@ -23,6 +23,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* owner_;
-    int bit_index_;
+    const char* owner_ = nullptr;
+    int bit_index_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_bitmap.h b/src/accessor/grib_accessor_class_bitmap.h
index 5d880d086..73f4ba336 100644
--- a/src/accessor/grib_accessor_class_bitmap.h
+++ b/src/accessor/grib_accessor_class_bitmap.h
@@ -31,12 +31,12 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 protected:
-    const char* missing_value_;
+    const char* missing_value_ = nullptr;
 
 private:
-    const char* tableReference_;
-    const char* offsetbsec_;
-    const char* sLength_;
+    const char* tableReference_ = nullptr;
+    const char* offsetbsec_ = nullptr;
+    const char* sLength_ = nullptr;
 
     void compute_size();
 };
diff --git a/src/accessor/grib_accessor_class_bits.h b/src/accessor/grib_accessor_class_bits.h
index 246b89747..cd3a56680 100644
--- a/src/accessor/grib_accessor_class_bits.h
+++ b/src/accessor/grib_accessor_class_bits.h
@@ -29,10 +29,10 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* argument_;
-    long start_;
-    long len_;
-    double referenceValue_;
-    double referenceValuePresent_;
-    double scale_;
+    const char* argument_ = nullptr;
+    long start_ = 0;
+    long len_ = 0;
+    double referenceValue_ = 0.;
+    double referenceValuePresent_ = 0.;
+    double scale_ = 0.;
 };
diff --git a/src/accessor/grib_accessor_class_bits_per_value.h b/src/accessor/grib_accessor_class_bits_per_value.h
index 7ccaf90f5..847c5e5ad 100644
--- a/src/accessor/grib_accessor_class_bits_per_value.h
+++ b/src/accessor/grib_accessor_class_bits_per_value.h
@@ -23,6 +23,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* bits_per_value_;
+    const char* values_ = nullptr;
+    const char* bits_per_value_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_budgdate.h b/src/accessor/grib_accessor_class_budgdate.h
index 655a5da16..ee218a34b 100644
--- a/src/accessor/grib_accessor_class_budgdate.h
+++ b/src/accessor/grib_accessor_class_budgdate.h
@@ -23,7 +23,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* year_;
-    const char* month_;
-    const char* day_;
+    const char* year_ = nullptr;
+    const char* month_ = nullptr;
+    const char* day_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_bufr_data_array.h b/src/accessor/grib_accessor_class_bufr_data_array.h
index 4d104126e..95bc2889e 100644
--- a/src/accessor/grib_accessor_class_bufr_data_array.h
+++ b/src/accessor/grib_accessor_class_bufr_data_array.h
@@ -47,53 +47,53 @@ public:
     grib_vsarray* accessor_bufr_data_array_get_stringValues();
 
 private:
-    const char* bufrDataEncodedName_;
-    const char* numberOfSubsetsName_;
-    const char* expandedDescriptorsName_;
-    const char* flagsName_;
-    const char* unitsName_;
-    const char* elementsDescriptorsIndexName_;
-    const char* compressedDataName_;
-    bufr_descriptors_array* expanded_;
-    grib_accessor_expanded_descriptors_t* expandedAccessor_;
-    int* canBeMissing_;
-    long numberOfSubsets_;
-    long compressedData_;
-    grib_vdarray* numericValues_;
-    grib_vsarray* stringValues_;
-    grib_viarray* elementsDescriptorsIndex_;
-    int do_decode_;
-    int bitmapStartElementsDescriptorsIndex_;
-    int bitmapCurrentElementsDescriptorsIndex_;
-    int bitmapSize_;
-    int bitmapStart_;
-    int bitmapCurrent_;
-    grib_accessors_list* dataAccessors_;
-    int unpackMode_;
-    int bitsToEndData_;
-    grib_section* dataKeys_;
-    double* inputBitmap_;
-    int nInputBitmap_;
-    int iInputBitmap_;
-    long* inputReplications_;
-    int nInputReplications_;
-    int iInputReplications_;
-    long* inputExtendedReplications_;
-    int nInputExtendedReplications_;
-    int iInputExtendedReplications_;
-    long* inputShortReplications_;
-    int nInputShortReplications_;
-    int iInputShortReplications_;
-    grib_iarray* iss_list_;
-    grib_trie_with_rank* dataAccessorsTrie_;
-    grib_sarray* tempStrings_;
-    grib_vdarray* tempDoubleValues_;
-    int change_ref_value_operand_;
-    size_t refValListSize_;
-    long* refValList_;
-    long refValIndex_;
-    bufr_tableb_override* tableb_override_;
-    int set_to_missing_if_out_of_range_;
+    const char* bufrDataEncodedName_ = nullptr;
+    const char* numberOfSubsetsName_ = nullptr;
+    const char* expandedDescriptorsName_ = nullptr;
+    const char* flagsName_ = nullptr;
+    const char* unitsName_ = nullptr;
+    const char* elementsDescriptorsIndexName_ = nullptr;
+    const char* compressedDataName_ = nullptr;
+    bufr_descriptors_array* expanded_ = nullptr;
+    grib_accessor_expanded_descriptors_t* expandedAccessor_ = nullptr;
+    int* canBeMissing_ = nullptr;
+    long numberOfSubsets_ = 0;
+    long compressedData_ = 0;
+    grib_vdarray* numericValues_ = nullptr;
+    grib_vsarray* stringValues_ = nullptr;
+    grib_viarray* elementsDescriptorsIndex_ = nullptr;
+    int do_decode_ = 0;
+    int bitmapStartElementsDescriptorsIndex_ = 0;
+    int bitmapCurrentElementsDescriptorsIndex_ = 0;
+    int bitmapSize_ = 0;
+    int bitmapStart_ = 0;
+    int bitmapCurrent_ = 0;
+    grib_accessors_list* dataAccessors_ = nullptr;
+    int unpackMode_ = 0;
+    int bitsToEndData_ = 0;
+    grib_section* dataKeys_ = nullptr;
+    double* inputBitmap_ = nullptr;
+    int nInputBitmap_ = 0;
+    int iInputBitmap_ = 0;
+    long* inputReplications_ = nullptr;
+    int nInputReplications_ = 0;
+    int iInputReplications_ = 0;
+    long* inputExtendedReplications_ = nullptr;
+    int nInputExtendedReplications_ = 0;
+    int iInputExtendedReplications_ = 0;
+    long* inputShortReplications_ = nullptr;
+    int nInputShortReplications_ = 0;
+    int iInputShortReplications_ = 0;
+    grib_iarray* iss_list_ = nullptr;
+    grib_trie_with_rank* dataAccessorsTrie_ = nullptr;
+    grib_sarray* tempStrings_ = nullptr;
+    grib_vdarray* tempDoubleValues_ = nullptr;
+    int change_ref_value_operand_ = 0;
+    size_t refValListSize_ = 0;
+    long* refValList_ = nullptr;
+    long refValIndex_ = 0;
+    bufr_tableb_override* tableb_override_ = nullptr;
+    int set_to_missing_if_out_of_range_ = 0;
 
     void restart_bitmap();
     void cancel_bitmap();
diff --git a/src/accessor/grib_accessor_class_bufr_data_element.h b/src/accessor/grib_accessor_class_bufr_data_element.h
index 86e69d2b0..c2bb80da9 100644
--- a/src/accessor/grib_accessor_class_bufr_data_element.h
+++ b/src/accessor/grib_accessor_class_bufr_data_element.h
@@ -48,14 +48,14 @@ public:
     void elementsDescriptorsIndex(grib_viarray* elementsDescriptorsIndex) { elementsDescriptorsIndex_ = elementsDescriptorsIndex; }
 
 private:
-    long index_;
-    int type_;
-    long compressedData_;
-    long subsetNumber_;
-    long numberOfSubsets_;
-    bufr_descriptors_array* descriptors_;
-    grib_vdarray* numericValues_;
-    grib_vsarray* stringValues_;
-    grib_viarray* elementsDescriptorsIndex_;
-    char* cname_;
+    long index_ = 0;
+    int type_ = 0;
+    long compressedData_ = 0;
+    long subsetNumber_ = 0;
+    long numberOfSubsets_ = 0;
+    bufr_descriptors_array* descriptors_ = nullptr;
+    grib_vdarray* numericValues_ = nullptr;
+    grib_vsarray* stringValues_ = nullptr;
+    grib_viarray* elementsDescriptorsIndex_ = nullptr;
+    char* cname_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_bufr_elements_table.h b/src/accessor/grib_accessor_class_bufr_elements_table.h
index 3736c0d8e..ba1ed3389 100644
--- a/src/accessor/grib_accessor_class_bufr_elements_table.h
+++ b/src/accessor/grib_accessor_class_bufr_elements_table.h
@@ -26,9 +26,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* dictionary_;
-    const char* masterDir_;
-    const char* localDir_;
+    const char* dictionary_ = nullptr;
+    const char* masterDir_ = nullptr;
+    const char* localDir_ = nullptr;
 
     grib_trie* load_bufr_elements_table(int* err);
     int bufr_get_from_table(bufr_descriptor* v);
diff --git a/src/accessor/grib_accessor_class_bufr_extract_area_subsets.h b/src/accessor/grib_accessor_class_bufr_extract_area_subsets.h
index 9f508b5a9..cbe9bca0d 100644
--- a/src/accessor/grib_accessor_class_bufr_extract_area_subsets.h
+++ b/src/accessor/grib_accessor_class_bufr_extract_area_subsets.h
@@ -23,16 +23,16 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* doExtractSubsets_;
-    const char* numberOfSubsets_;
-    const char* extractSubsetList_;
-    const char* extractAreaWestLongitude_;
-    const char* extractAreaEastLongitude_;
-    const char* extractAreaNorthLatitude_;
-    const char* extractAreaSouthLatitude_;
-    const char* extractAreaLongitudeRank_;
-    const char* extractAreaLatitudeRank_;
-    const char* extractedAreaNumberOfSubsets_;
+    const char* doExtractSubsets_ = nullptr;
+    const char* numberOfSubsets_ = nullptr;
+    const char* extractSubsetList_ = nullptr;
+    const char* extractAreaWestLongitude_ = nullptr;
+    const char* extractAreaEastLongitude_ = nullptr;
+    const char* extractAreaNorthLatitude_ = nullptr;
+    const char* extractAreaSouthLatitude_ = nullptr;
+    const char* extractAreaLongitudeRank_ = nullptr;
+    const char* extractAreaLatitudeRank_ = nullptr;
+    const char* extractedAreaNumberOfSubsets_ = nullptr;
 
     int select_area();
 };
diff --git a/src/accessor/grib_accessor_class_bufr_extract_datetime_subsets.h b/src/accessor/grib_accessor_class_bufr_extract_datetime_subsets.h
index 977dc1104..df81d6e12 100644
--- a/src/accessor/grib_accessor_class_bufr_extract_datetime_subsets.h
+++ b/src/accessor/grib_accessor_class_bufr_extract_datetime_subsets.h
@@ -23,9 +23,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* doExtractSubsets_;
-    const char* numberOfSubsets_;
-    const char* extractSubsetList_;
+    const char* doExtractSubsets_ = nullptr;
+    const char* numberOfSubsets_ = nullptr;
+    const char* extractSubsetList_ = nullptr;
 
     int select_datetime();
 };
diff --git a/src/accessor/grib_accessor_class_bufr_extract_subsets.h b/src/accessor/grib_accessor_class_bufr_extract_subsets.h
index 5ef9e73cf..1128bb7e6 100644
--- a/src/accessor/grib_accessor_class_bufr_extract_subsets.h
+++ b/src/accessor/grib_accessor_class_bufr_extract_subsets.h
@@ -23,10 +23,10 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* numericValues_;
-    const char* pack_;
-    grib_accessor* numericValuesAccessor_;
-    grib_accessor* packAccessor_;
+    const char* numericValues_ = nullptr;
+    const char* pack_ = nullptr;
+    grib_accessor* numericValuesAccessor_ = nullptr;
+    grib_accessor* packAccessor_ = nullptr;
 
     void get_accessors();
 };
diff --git a/src/accessor/grib_accessor_class_bufr_simple_thinning.h b/src/accessor/grib_accessor_class_bufr_simple_thinning.h
index 34fa5fb2f..2c92a69df 100644
--- a/src/accessor/grib_accessor_class_bufr_simple_thinning.h
+++ b/src/accessor/grib_accessor_class_bufr_simple_thinning.h
@@ -23,12 +23,12 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* doExtractSubsets_;
-    const char* numberOfSubsets_;
-    const char* extractSubsetList_;
-    const char* simpleThinningStart_;
-    const char* simpleThinningMissingRadius_;
-    const char* simpleThinningSkip_;
+    const char* doExtractSubsets_ = nullptr;
+    const char* numberOfSubsets_ = nullptr;
+    const char* extractSubsetList_ = nullptr;
+    const char* simpleThinningStart_ = nullptr;
+    const char* simpleThinningMissingRadius_ = nullptr;
+    const char* simpleThinningSkip_ = nullptr;
 
     int apply_thinning();
 };
diff --git a/src/accessor/grib_accessor_class_bufr_string_values.h b/src/accessor/grib_accessor_class_bufr_string_values.h
index a566fd4d8..77a0e8b30 100644
--- a/src/accessor/grib_accessor_class_bufr_string_values.h
+++ b/src/accessor/grib_accessor_class_bufr_string_values.h
@@ -26,8 +26,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* dataAccessorName_;
-    grib_accessor* dataAccessor_;
+    const char* dataAccessorName_ = nullptr;
+    grib_accessor* dataAccessor_ = nullptr;
 
     grib_accessor* get_accessor();
 };
diff --git a/src/accessor/grib_accessor_class_bufrdc_expanded_descriptors.h b/src/accessor/grib_accessor_class_bufrdc_expanded_descriptors.h
index 01fb97b98..f46110649 100644
--- a/src/accessor/grib_accessor_class_bufrdc_expanded_descriptors.h
+++ b/src/accessor/grib_accessor_class_bufrdc_expanded_descriptors.h
@@ -25,8 +25,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* expandedDescriptors_;
-    grib_accessor* expandedDescriptorsAccessor_;
+    const char* expandedDescriptors_ = nullptr;
+    grib_accessor* expandedDescriptorsAccessor_ = nullptr;
 
     grib_accessor* get_accessor();
 };
diff --git a/src/accessor/grib_accessor_class_cf_var_name.h b/src/accessor/grib_accessor_class_cf_var_name.h
index 8073d91d1..8e7ed05d5 100644
--- a/src/accessor/grib_accessor_class_cf_var_name.h
+++ b/src/accessor/grib_accessor_class_cf_var_name.h
@@ -24,5 +24,5 @@ public:
 
 private:
     /* Members defined in cf_var_name */
-    const char* defaultKey_;
+    const char* defaultKey_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_change_alternative_row_scanning.h b/src/accessor/grib_accessor_class_change_alternative_row_scanning.h
index 885ca06dc..1ece123d4 100644
--- a/src/accessor/grib_accessor_class_change_alternative_row_scanning.h
+++ b/src/accessor/grib_accessor_class_change_alternative_row_scanning.h
@@ -24,8 +24,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* Ni_;
-    const char* Nj_;
-    const char* alternativeRowScanning_;
+    const char* values_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* Nj_ = nullptr;
+    const char* alternativeRowScanning_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_change_scanning_direction.h b/src/accessor/grib_accessor_class_change_scanning_direction.h
index 72c3387a6..e26a0e104 100644
--- a/src/accessor/grib_accessor_class_change_scanning_direction.h
+++ b/src/accessor/grib_accessor_class_change_scanning_direction.h
@@ -24,12 +24,12 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* Ni_;
-    const char* Nj_;
-    const char* i_scans_negatively_;
-    const char* j_scans_positively_;
-    const char* first_;
-    const char* last_;
-    const char* axis_;
+    const char* values_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* Nj_ = nullptr;
+    const char* i_scans_negatively_ = nullptr;
+    const char* j_scans_positively_ = nullptr;
+    const char* first_ = nullptr;
+    const char* last_ = nullptr;
+    const char* axis_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_closest_date.h b/src/accessor/grib_accessor_class_closest_date.h
index 8e2a7a254..cea1c9b87 100644
--- a/src/accessor/grib_accessor_class_closest_date.h
+++ b/src/accessor/grib_accessor_class_closest_date.h
@@ -24,13 +24,13 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* dateLocal_;
-    const char* timeLocal_;
-    const char* numForecasts_;
-    const char* year_;
-    const char* month_;
-    const char* day_;
-    const char* hour_;
-    const char* minute_;
-    const char* second_;
+    const char* dateLocal_ = nullptr;
+    const char* timeLocal_ = nullptr;
+    const char* numForecasts_ = nullptr;
+    const char* year_ = nullptr;
+    const char* month_ = nullptr;
+    const char* day_ = nullptr;
+    const char* hour_ = nullptr;
+    const char* minute_ = nullptr;
+    const char* second_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_codeflag.h b/src/accessor/grib_accessor_class_codeflag.h
index 1cdbfa561..9aa8f62a0 100644
--- a/src/accessor/grib_accessor_class_codeflag.h
+++ b/src/accessor/grib_accessor_class_codeflag.h
@@ -23,7 +23,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* tablename_;
+    const char* tablename_ = nullptr;
 
     int grib_get_codeflag(long code, char* codename);
 };
diff --git a/src/accessor/grib_accessor_class_codetable.h b/src/accessor/grib_accessor_class_codetable.h
index 45e56415f..cc8e36b3d 100644
--- a/src/accessor/grib_accessor_class_codetable.h
+++ b/src/accessor/grib_accessor_class_codetable.h
@@ -33,11 +33,11 @@ public:
     grib_codetable* codetable() const { return table_; }
 
 private:
-    grib_codetable* table_;
-    const char* tablename_;
-    const char* masterDir_;
-    const char* localDir_;
-    int table_loaded_;
+    grib_codetable* table_ = nullptr;
+    const char* tablename_ = nullptr;
+    const char* masterDir_ = nullptr;
+    const char* localDir_ = nullptr;
+    int table_loaded_ = 0;
 
     grib_codetable* load_table();
 };
diff --git a/src/accessor/grib_accessor_class_codetable_title.h b/src/accessor/grib_accessor_class_codetable_title.h
index 728aa4e23..625d15aef 100644
--- a/src/accessor/grib_accessor_class_codetable_title.h
+++ b/src/accessor/grib_accessor_class_codetable_title.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* codetable_;
+    const char* codetable_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_codetable_units.h b/src/accessor/grib_accessor_class_codetable_units.h
index 6d1410f0a..86ad6e652 100644
--- a/src/accessor/grib_accessor_class_codetable_units.h
+++ b/src/accessor/grib_accessor_class_codetable_units.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* codetable_;
+    const char* codetable_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_count_missing.h b/src/accessor/grib_accessor_class_count_missing.h
index 0c1e8207f..4e3fb6d82 100644
--- a/src/accessor/grib_accessor_class_count_missing.h
+++ b/src/accessor/grib_accessor_class_count_missing.h
@@ -23,8 +23,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* bitmap_;
-    const char* unusedBitsInBitmap_;
-    const char* numberOfDataPoints_;
-    const char* missingValueManagementUsed_;
+    const char* bitmap_ = nullptr;
+    const char* unusedBitsInBitmap_ = nullptr;
+    const char* numberOfDataPoints_ = nullptr;
+    const char* missingValueManagementUsed_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_apply_bitmap.h b/src/accessor/grib_accessor_class_data_apply_bitmap.h
index bfcc41e47..26f90ce47 100644
--- a/src/accessor/grib_accessor_class_data_apply_bitmap.h
+++ b/src/accessor/grib_accessor_class_data_apply_bitmap.h
@@ -30,12 +30,12 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* coded_values_;
-    const char* bitmap_;
-    const char* missing_value_;
-    const char* number_of_data_points_;
-    const char* number_of_values_;
-    const char* binary_scale_factor_;
+    const char* coded_values_ = nullptr;
+    const char* bitmap_ = nullptr;
+    const char* missing_value_ = nullptr;
+    const char* number_of_data_points_ = nullptr;
+    const char* number_of_values_ = nullptr;
+    const char* binary_scale_factor_ = nullptr;
 
     template <typename T> int unpack(T* val, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_data_apply_boustrophedonic.h b/src/accessor/grib_accessor_class_data_apply_boustrophedonic.h
index 76aae84c6..1c6b78799 100644
--- a/src/accessor/grib_accessor_class_data_apply_boustrophedonic.h
+++ b/src/accessor/grib_accessor_class_data_apply_boustrophedonic.h
@@ -29,11 +29,11 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* values_;
-    const char* numberOfRows_;
-    const char* numberOfColumns_;
-    const char* numberOfPoints_;
-    const char* pl_;
+    const char* values_ = nullptr;
+    const char* numberOfRows_ = nullptr;
+    const char* numberOfColumns_ = nullptr;
+    const char* numberOfPoints_ = nullptr;
+    const char* pl_ = nullptr;
 
     template <typename T> int unpack(T* val, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_data_apply_boustrophedonic_bitmap.h b/src/accessor/grib_accessor_class_data_apply_boustrophedonic_bitmap.h
index f8e9a193f..21560f201 100644
--- a/src/accessor/grib_accessor_class_data_apply_boustrophedonic_bitmap.h
+++ b/src/accessor/grib_accessor_class_data_apply_boustrophedonic_bitmap.h
@@ -28,11 +28,11 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* coded_values_;
-    const char* bitmap_;
-    const char* missing_value_;
-    const char* binary_scale_factor_;
-    const char* numberOfRows_;
-    const char* numberOfColumns_;
-    const char* numberOfPoints_;
+    const char* coded_values_ = nullptr;
+    const char* bitmap_ = nullptr;
+    const char* missing_value_ = nullptr;
+    const char* binary_scale_factor_ = nullptr;
+    const char* numberOfRows_ = nullptr;
+    const char* numberOfColumns_ = nullptr;
+    const char* numberOfPoints_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_ccsds_packing.h b/src/accessor/grib_accessor_class_data_ccsds_packing.h
index 7ae72d514..be170db8f 100644
--- a/src/accessor/grib_accessor_class_data_ccsds_packing.h
+++ b/src/accessor/grib_accessor_class_data_ccsds_packing.h
@@ -28,16 +28,16 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* number_of_values_;
-    const char* reference_value_;
-    const char* binary_scale_factor_;
-    const char* decimal_scale_factor_;
-    const char* optimize_scaling_factor_;
-    const char* bits_per_value_;
-    const char* number_of_data_points_;
-    const char* ccsds_flags_;
-    const char* ccsds_block_size_;
-    const char* ccsds_rsi_;
+    const char* number_of_values_ = nullptr;
+    const char* reference_value_ = nullptr;
+    const char* binary_scale_factor_ = nullptr;
+    const char* decimal_scale_factor_ = nullptr;
+    const char* optimize_scaling_factor_ = nullptr;
+    const char* bits_per_value_ = nullptr;
+    const char* number_of_data_points_ = nullptr;
+    const char* ccsds_flags_ = nullptr;
+    const char* ccsds_block_size_ = nullptr;
+    const char* ccsds_rsi_ = nullptr;
 
     template <typename T> int unpack(T* val, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_data_complex_packing.h b/src/accessor/grib_accessor_class_data_complex_packing.h
index 58c1b6fa2..1124e5d5e 100644
--- a/src/accessor/grib_accessor_class_data_complex_packing.h
+++ b/src/accessor/grib_accessor_class_data_complex_packing.h
@@ -30,18 +30,18 @@ public:
     void init(const long, grib_arguments*) override;
 
 protected:
-    const char* sub_j_;
-    const char* sub_k_;
-    const char* sub_m_;
+    const char* sub_j_ = nullptr;
+    const char* sub_k_ = nullptr;
+    const char* sub_m_ = nullptr;
 
 private:
-    const char* GRIBEX_sh_bug_present_;
-    const char* ieee_floats_;
-    const char* laplacianOperatorIsSet_;
-    const char* laplacianOperator_;
-    const char* pen_j_;
-    const char* pen_k_;
-    const char* pen_m_;
+    const char* GRIBEX_sh_bug_present_ = nullptr;
+    const char* ieee_floats_ = nullptr;
+    const char* laplacianOperatorIsSet_ = nullptr;
+    const char* laplacianOperator_ = nullptr;
+    const char* pen_j_ = nullptr;
+    const char* pen_k_ = nullptr;
+    const char* pen_m_ = nullptr;
 
     template <typename T> int unpack_real(T* val, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_data_dummy_field.h b/src/accessor/grib_accessor_class_data_dummy_field.h
index 80cf045bc..4a22f904f 100644
--- a/src/accessor/grib_accessor_class_data_dummy_field.h
+++ b/src/accessor/grib_accessor_class_data_dummy_field.h
@@ -24,7 +24,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* missing_value_;
-    const char* numberOfPoints_;
-    const char* bitmap_;
+    const char* missing_value_ = nullptr;
+    const char* numberOfPoints_ = nullptr;
+    const char* bitmap_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g1complex_packing.h b/src/accessor/grib_accessor_class_data_g1complex_packing.h
index 6bf7430e9..5b3a86b39 100644
--- a/src/accessor/grib_accessor_class_data_g1complex_packing.h
+++ b/src/accessor/grib_accessor_class_data_g1complex_packing.h
@@ -22,9 +22,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* N_;
-    const char* half_byte_;
-    const char* packingType_;
-    const char* ieee_packing_;
-    const char* precision_;
+    const char* N_ = nullptr;
+    const char* half_byte_ = nullptr;
+    const char* packingType_ = nullptr;
+    const char* ieee_packing_ = nullptr;
+    const char* precision_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g1second_order_constant_width_packing.h b/src/accessor/grib_accessor_class_data_g1second_order_constant_width_packing.h
index 0d42e7c7f..4ba3822bc 100644
--- a/src/accessor/grib_accessor_class_data_g1second_order_constant_width_packing.h
+++ b/src/accessor/grib_accessor_class_data_g1second_order_constant_width_packing.h
@@ -27,20 +27,20 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* half_byte_;
-    const char* packingType_;
-    const char* ieee_packing_;
-    const char* precision_;
-    const char* widthOfFirstOrderValues_;
-    const char* N1_;
-    const char* N2_;
-    const char* numberOfGroups_;
-    const char* numberOfSecondOrderPackedValues_;
-    const char* extraValues_;
-    const char* pl_;
-    const char* Ni_;
-    const char* Nj_;
-    const char* jPointsAreConsecutive_;
-    const char* bitmap_;
-    const char* groupWidth_;
+    const char* half_byte_ = nullptr;
+    const char* packingType_ = nullptr;
+    const char* ieee_packing_ = nullptr;
+    const char* precision_ = nullptr;
+    const char* widthOfFirstOrderValues_ = nullptr;
+    const char* N1_ = nullptr;
+    const char* N2_ = nullptr;
+    const char* numberOfGroups_ = nullptr;
+    const char* numberOfSecondOrderPackedValues_ = nullptr;
+    const char* extraValues_ = nullptr;
+    const char* pl_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* Nj_ = nullptr;
+    const char* jPointsAreConsecutive_ = nullptr;
+    const char* bitmap_ = nullptr;
+    const char* groupWidth_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g1second_order_general_extended_packing.h b/src/accessor/grib_accessor_class_data_g1second_order_general_extended_packing.h
index e278080f2..0f155ba92 100644
--- a/src/accessor/grib_accessor_class_data_g1second_order_general_extended_packing.h
+++ b/src/accessor/grib_accessor_class_data_g1second_order_general_extended_packing.h
@@ -31,31 +31,31 @@ private:
     int unpack(double*, float*, size_t*);
 
 private:
-    const char* half_byte_;
-    const char* packingType_;
-    const char* ieee_packing_;
-    const char* precision_;
-    const char* widthOfFirstOrderValues_;
-    const char* firstOrderValues_;
-    const char* N1_;
-    const char* N2_;
-    const char* numberOfGroups_;
-    const char* codedNumberOfGroups_;
-    const char* numberOfSecondOrderPackedValues_;
-    const char* extraValues_;
-    const char* groupWidths_;
-    const char* widthOfWidths_;
-    const char* groupLengths_;
-    const char* widthOfLengths_;
-    const char* NL_;
-    const char* SPD_;
-    const char* widthOfSPD_;
-    const char* orderOfSPD_;
-    const char* numberOfPoints_;
-    const char* dataFlag_;
-    double* dvalues_;
-    float* fvalues_;
-    int double_dirty_;
-    int float_dirty_;
-    size_t size_;
+    const char* half_byte_ = nullptr;
+    const char* packingType_ = nullptr;
+    const char* ieee_packing_ = nullptr;
+    const char* precision_ = nullptr;
+    const char* widthOfFirstOrderValues_ = nullptr;
+    const char* firstOrderValues_ = nullptr;
+    const char* N1_ = nullptr;
+    const char* N2_ = nullptr;
+    const char* numberOfGroups_ = nullptr;
+    const char* codedNumberOfGroups_ = nullptr;
+    const char* numberOfSecondOrderPackedValues_ = nullptr;
+    const char* extraValues_ = nullptr;
+    const char* groupWidths_ = nullptr;
+    const char* widthOfWidths_ = nullptr;
+    const char* groupLengths_ = nullptr;
+    const char* widthOfLengths_ = nullptr;
+    const char* NL_ = nullptr;
+    const char* SPD_ = nullptr;
+    const char* widthOfSPD_ = nullptr;
+    const char* orderOfSPD_ = nullptr;
+    const char* numberOfPoints_ = nullptr;
+    const char* dataFlag_ = nullptr;
+    double* dvalues_ = nullptr;
+    float* fvalues_ = nullptr;
+    int double_dirty_ = 0;
+    int float_dirty_ = 0;
+    size_t size_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_data_g1second_order_general_packing.h b/src/accessor/grib_accessor_class_data_g1second_order_general_packing.h
index 159e1f98c..174c63fd0 100644
--- a/src/accessor/grib_accessor_class_data_g1second_order_general_packing.h
+++ b/src/accessor/grib_accessor_class_data_g1second_order_general_packing.h
@@ -26,22 +26,22 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* half_byte_;
-    const char* packingType_;
-    const char* ieee_packing_;
-    const char* precision_;
-    const char* widthOfFirstOrderValues_;
-    const char* N1_;
-    const char* N2_;
-    const char* numberOfGroups_;
-    const char* numberOfSecondOrderPackedValues_;
-    const char* extraValues_;
-    const char* pl_;
-    const char* Ni_;
-    const char* Nj_;
-    const char* jPointsAreConsecutive_;
-    const char* bitmap_;
-    const char* groupWidths_;
+    const char* half_byte_ = nullptr;
+    const char* packingType_ = nullptr;
+    const char* ieee_packing_ = nullptr;
+    const char* precision_ = nullptr;
+    const char* widthOfFirstOrderValues_ = nullptr;
+    const char* N1_ = nullptr;
+    const char* N2_ = nullptr;
+    const char* numberOfGroups_ = nullptr;
+    const char* numberOfSecondOrderPackedValues_ = nullptr;
+    const char* extraValues_ = nullptr;
+    const char* pl_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* Nj_ = nullptr;
+    const char* jPointsAreConsecutive_ = nullptr;
+    const char* bitmap_ = nullptr;
+    const char* groupWidths_ = nullptr;
 
     template <typename T> int unpack_real(T* values, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_data_g1second_order_row_by_row_packing.h b/src/accessor/grib_accessor_class_data_g1second_order_row_by_row_packing.h
index 263830ad8..adde49272 100644
--- a/src/accessor/grib_accessor_class_data_g1second_order_row_by_row_packing.h
+++ b/src/accessor/grib_accessor_class_data_g1second_order_row_by_row_packing.h
@@ -26,22 +26,22 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* half_byte_;
-    const char* packingType_;
-    const char* ieee_packing_;
-    const char* precision_;
-    const char* widthOfFirstOrderValues_;
-    const char* N1_;
-    const char* N2_;
-    const char* numberOfGroups_;
-    const char* numberOfSecondOrderPackedValues_;
-    const char* extraValues_;
-    const char* pl_;
-    const char* Ni_;
-    const char* Nj_;
-    const char* jPointsAreConsecutive_;
-    const char* bitmap_;
-    const char* groupWidths_;
+    const char* half_byte_ = nullptr;
+    const char* packingType_ = nullptr;
+    const char* ieee_packing_ = nullptr;
+    const char* precision_ = nullptr;
+    const char* widthOfFirstOrderValues_ = nullptr;
+    const char* N1_ = nullptr;
+    const char* N2_ = nullptr;
+    const char* numberOfGroups_ = nullptr;
+    const char* numberOfSecondOrderPackedValues_ = nullptr;
+    const char* extraValues_ = nullptr;
+    const char* pl_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* Nj_ = nullptr;
+    const char* jPointsAreConsecutive_ = nullptr;
+    const char* bitmap_ = nullptr;
+    const char* groupWidths_ = nullptr;
 
     template <typename T> int unpack_real(T* values, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_data_g1secondary_bitmap.h b/src/accessor/grib_accessor_class_data_g1secondary_bitmap.h
index 0a5d492c8..c93897d7e 100644
--- a/src/accessor/grib_accessor_class_data_g1secondary_bitmap.h
+++ b/src/accessor/grib_accessor_class_data_g1secondary_bitmap.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* number_of_ones_;
+    const char* number_of_ones_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g1simple_packing.h b/src/accessor/grib_accessor_class_data_g1simple_packing.h
index 789648747..2df6c49fe 100644
--- a/src/accessor/grib_accessor_class_data_g1simple_packing.h
+++ b/src/accessor/grib_accessor_class_data_g1simple_packing.h
@@ -23,8 +23,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 protected:
-    const char* half_byte_;
-    const char* packingType_;
-    const char* ieee_packing_;
-    const char* precision_;
+    const char* half_byte_ = nullptr;
+    const char* packingType_ = nullptr;
+    const char* ieee_packing_ = nullptr;
+    const char* precision_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g22order_packing.h b/src/accessor/grib_accessor_class_data_g22order_packing.h
index f8c015afe..a21c0206e 100644
--- a/src/accessor/grib_accessor_class_data_g22order_packing.h
+++ b/src/accessor/grib_accessor_class_data_g22order_packing.h
@@ -28,26 +28,26 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* numberOfValues_;
-    const char* bits_per_value_;
-    const char* reference_value_;
-    const char* binary_scale_factor_;
-    const char* decimal_scale_factor_;
-    const char* optimize_scale_factor_;
-    const char* typeOfOriginalFieldValues_;
-    const char* groupSplittingMethodUsed_;
-    const char* missingValueManagementUsed_;
-    const char* primaryMissingValueSubstitute_;
-    const char* secondaryMissingValueSubstitute_;
-    const char* numberOfGroupsOfDataValues_;
-    const char* referenceForGroupWidths_;
-    const char* numberOfBitsUsedForTheGroupWidths_;
-    const char* referenceForGroupLengths_;
-    const char* lengthIncrementForTheGroupLengths_;
-    const char* trueLengthOfLastGroup_;
-    const char* numberOfBitsUsedForTheScaledGroupLengths_;
-    const char* orderOfSpatialDifferencing_;
-    const char* numberOfOctetsExtraDescriptors_;
+    const char* numberOfValues_ = nullptr;
+    const char* bits_per_value_ = nullptr;
+    const char* reference_value_ = nullptr;
+    const char* binary_scale_factor_ = nullptr;
+    const char* decimal_scale_factor_ = nullptr;
+    const char* optimize_scale_factor_ = nullptr;
+    const char* typeOfOriginalFieldValues_ = nullptr;
+    const char* groupSplittingMethodUsed_ = nullptr;
+    const char* missingValueManagementUsed_ = nullptr;
+    const char* primaryMissingValueSubstitute_ = nullptr;
+    const char* secondaryMissingValueSubstitute_ = nullptr;
+    const char* numberOfGroupsOfDataValues_ = nullptr;
+    const char* referenceForGroupWidths_ = nullptr;
+    const char* numberOfBitsUsedForTheGroupWidths_ = nullptr;
+    const char* referenceForGroupLengths_ = nullptr;
+    const char* lengthIncrementForTheGroupLengths_ = nullptr;
+    const char* trueLengthOfLastGroup_ = nullptr;
+    const char* numberOfBitsUsedForTheScaledGroupLengths_ = nullptr;
+    const char* orderOfSpatialDifferencing_ = nullptr;
+    const char* numberOfOctetsExtraDescriptors_ = nullptr;
 
     template <typename T> int unpack(T* val, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_data_g2bifourier_packing.h b/src/accessor/grib_accessor_class_data_g2bifourier_packing.h
index 9c2471060..0690aebb9 100644
--- a/src/accessor/grib_accessor_class_data_g2bifourier_packing.h
+++ b/src/accessor/grib_accessor_class_data_g2bifourier_packing.h
@@ -53,19 +53,19 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* ieee_floats_;
-    const char* laplacianOperatorIsSet_;
-    const char* laplacianOperator_;
-    const char* biFourierTruncationType_;
-    const char* sub_i_;
-    const char* sub_j_;
-    const char* bif_i_;
-    const char* bif_j_;
-    const char* biFourierSubTruncationType_;
-    const char* biFourierDoNotPackAxes_;
-    const char* biFourierMakeTemplate_;
-    const char* totalNumberOfValuesInUnpackedSubset_;
-    //const char* numberOfValues_;
+    const char* ieee_floats_ = nullptr;
+    const char* laplacianOperatorIsSet_ = nullptr;
+    const char* laplacianOperator_ = nullptr;
+    const char* biFourierTruncationType_ = nullptr;
+    const char* sub_i_ = nullptr;
+    const char* sub_j_ = nullptr;
+    const char* bif_i_ = nullptr;
+    const char* bif_j_ = nullptr;
+    const char* biFourierSubTruncationType_ = nullptr;
+    const char* biFourierDoNotPackAxes_ = nullptr;
+    const char* biFourierMakeTemplate_ = nullptr;
+    const char* totalNumberOfValuesInUnpackedSubset_ = nullptr;
+    //const char* numberOfValues_ = nullptr;
 
     bif_trunc_t* new_bif_trunc();
 };
diff --git a/src/accessor/grib_accessor_class_data_g2complex_packing.h b/src/accessor/grib_accessor_class_data_g2complex_packing.h
index 75a9195fd..abe1fa97b 100644
--- a/src/accessor/grib_accessor_class_data_g2complex_packing.h
+++ b/src/accessor/grib_accessor_class_data_g2complex_packing.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* numberOfValues_;
+    const char* numberOfValues_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g2secondary_bitmap.h b/src/accessor/grib_accessor_class_data_g2secondary_bitmap.h
index 85c441891..368a3950e 100644
--- a/src/accessor/grib_accessor_class_data_g2secondary_bitmap.h
+++ b/src/accessor/grib_accessor_class_data_g2secondary_bitmap.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* number_of_values_;
+    const char* number_of_values_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g2shsimple_packing.h b/src/accessor/grib_accessor_class_data_g2shsimple_packing.h
index 9b24febca..ad0f1c51c 100644
--- a/src/accessor/grib_accessor_class_data_g2shsimple_packing.h
+++ b/src/accessor/grib_accessor_class_data_g2shsimple_packing.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* numberOfValues_;
-    const char* numberOfDataPoints_;
+    const char* numberOfValues_ = nullptr;
+    const char* numberOfDataPoints_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_g2simple_packing_with_preprocessing.h b/src/accessor/grib_accessor_class_data_g2simple_packing_with_preprocessing.h
index e1f8c5e99..bfd142afb 100644
--- a/src/accessor/grib_accessor_class_data_g2simple_packing_with_preprocessing.h
+++ b/src/accessor/grib_accessor_class_data_g2simple_packing_with_preprocessing.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* pre_processing_;
-    const char* pre_processing_parameter_;
+    const char* pre_processing_ = nullptr;
+    const char* pre_processing_parameter_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_jpeg2000_packing.h b/src/accessor/grib_accessor_class_data_jpeg2000_packing.h
index f6b4da513..9afcc183b 100644
--- a/src/accessor/grib_accessor_class_data_jpeg2000_packing.h
+++ b/src/accessor/grib_accessor_class_data_jpeg2000_packing.h
@@ -27,13 +27,13 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* type_of_compression_used_;
-    const char* target_compression_ratio_;
-    const char* ni_;
-    const char* nj_;
-    const char* list_defining_points_;
-    const char* number_of_data_points_;
-    const char* scanning_mode_;
-    int jpeg_lib_;
-    const char* dump_jpg_;
+    const char* type_of_compression_used_ = nullptr;
+    const char* target_compression_ratio_ = nullptr;
+    const char* ni_ = nullptr;
+    const char* nj_ = nullptr;
+    const char* list_defining_points_ = nullptr;
+    const char* number_of_data_points_ = nullptr;
+    const char* scanning_mode_ = nullptr;
+    int jpeg_lib_ = 0;
+    const char* dump_jpg_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_png_packing.h b/src/accessor/grib_accessor_class_data_png_packing.h
index 031def2ed..d47bc8726 100644
--- a/src/accessor/grib_accessor_class_data_png_packing.h
+++ b/src/accessor/grib_accessor_class_data_png_packing.h
@@ -26,14 +26,14 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* number_of_values_;
-    const char* reference_value_;
-    const char* binary_scale_factor_;
-    const char* decimal_scale_factor_;
-    const char* bits_per_value_;
-    const char* ni_;
-    const char* nj_;
-    const char* list_defining_points_;
-    const char* number_of_data_points_;
-    const char* scanning_mode_;
+    const char* number_of_values_ = nullptr;
+    const char* reference_value_ = nullptr;
+    const char* binary_scale_factor_ = nullptr;
+    const char* decimal_scale_factor_ = nullptr;
+    const char* bits_per_value_ = nullptr;
+    const char* ni_ = nullptr;
+    const char* nj_ = nullptr;
+    const char* list_defining_points_ = nullptr;
+    const char* number_of_data_points_ = nullptr;
+    const char* scanning_mode_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_raw_packing.h b/src/accessor/grib_accessor_class_data_raw_packing.h
index e61f15d1a..708436a83 100644
--- a/src/accessor/grib_accessor_class_data_raw_packing.h
+++ b/src/accessor/grib_accessor_class_data_raw_packing.h
@@ -26,6 +26,6 @@ public:
     int unpack_double_element_set(const size_t* index_array, size_t len, double* val_array) override;
 
 private:
-    const char* number_of_values_;
-    const char* precision_;
+    const char* number_of_values_ = nullptr;
+    const char* precision_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_run_length_packing.h b/src/accessor/grib_accessor_class_data_run_length_packing.h
index 8606a6ae0..f13e116eb 100644
--- a/src/accessor/grib_accessor_class_data_run_length_packing.h
+++ b/src/accessor/grib_accessor_class_data_run_length_packing.h
@@ -24,10 +24,10 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* number_of_values_;
-    const char* bits_per_value_;
-    const char* max_level_value_;
-    const char* number_of_level_values_;
-    const char* decimal_scale_factor_;
-    const char* level_values_;
+    const char* number_of_values_ = nullptr;
+    const char* bits_per_value_ = nullptr;
+    const char* max_level_value_ = nullptr;
+    const char* number_of_level_values_ = nullptr;
+    const char* decimal_scale_factor_ = nullptr;
+    const char* level_values_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_secondary_bitmap.h b/src/accessor/grib_accessor_class_data_secondary_bitmap.h
index 8abe594b3..5d20f61ae 100644
--- a/src/accessor/grib_accessor_class_data_secondary_bitmap.h
+++ b/src/accessor/grib_accessor_class_data_secondary_bitmap.h
@@ -24,8 +24,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 protected:
-    const char* primary_bitmap_;
-    const char* secondary_bitmap_;
-    const char* missing_value_;
-    const char* expand_by_;
+    const char* primary_bitmap_ = nullptr;
+    const char* secondary_bitmap_ = nullptr;
+    const char* missing_value_ = nullptr;
+    const char* expand_by_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_sh_packed.h b/src/accessor/grib_accessor_class_data_sh_packed.h
index 71d54b411..db74e60b6 100644
--- a/src/accessor/grib_accessor_class_data_sh_packed.h
+++ b/src/accessor/grib_accessor_class_data_sh_packed.h
@@ -23,14 +23,14 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* GRIBEX_sh_bug_present_;
-    const char* ieee_floats_;
-    const char* laplacianOperatorIsSet_;
-    const char* laplacianOperator_;
-    const char* sub_j_;
-    const char* sub_k_;
-    const char* sub_m_;
-    const char* pen_j_;
-    const char* pen_k_;
-    const char* pen_m_;
+    const char* GRIBEX_sh_bug_present_ = nullptr;
+    const char* ieee_floats_ = nullptr;
+    const char* laplacianOperatorIsSet_ = nullptr;
+    const char* laplacianOperator_ = nullptr;
+    const char* sub_j_ = nullptr;
+    const char* sub_k_ = nullptr;
+    const char* sub_m_ = nullptr;
+    const char* pen_j_ = nullptr;
+    const char* pen_k_ = nullptr;
+    const char* pen_m_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_sh_unpacked.h b/src/accessor/grib_accessor_class_data_sh_unpacked.h
index 29c283084..4d52bd231 100644
--- a/src/accessor/grib_accessor_class_data_sh_unpacked.h
+++ b/src/accessor/grib_accessor_class_data_sh_unpacked.h
@@ -23,14 +23,14 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* GRIBEX_sh_bug_present_;
-    const char* ieee_floats_;
-    const char* laplacianOperatorIsSet_;
-    const char* laplacianOperator_;
-    const char* sub_j_;
-    const char* sub_k_;
-    const char* sub_m_;
-    const char* pen_j_;
-    const char* pen_k_;
-    const char* pen_m_;
+    const char* GRIBEX_sh_bug_present_ = nullptr;
+    const char* ieee_floats_ = nullptr;
+    const char* laplacianOperatorIsSet_ = nullptr;
+    const char* laplacianOperator_ = nullptr;
+    const char* sub_j_ = nullptr;
+    const char* sub_k_ = nullptr;
+    const char* sub_m_ = nullptr;
+    const char* pen_j_ = nullptr;
+    const char* pen_k_ = nullptr;
+    const char* pen_m_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_shsimple_packing.h b/src/accessor/grib_accessor_class_data_shsimple_packing.h
index 6284c1944..b722dcbf1 100644
--- a/src/accessor/grib_accessor_class_data_shsimple_packing.h
+++ b/src/accessor/grib_accessor_class_data_shsimple_packing.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 protected:
-    const char* coded_values_;
-    const char* real_part_;
+    const char* coded_values_ = nullptr;
+    const char* real_part_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_data_simple_packing.h b/src/accessor/grib_accessor_class_data_simple_packing.h
index 960a90308..6fa71b324 100644
--- a/src/accessor/grib_accessor_class_data_simple_packing.h
+++ b/src/accessor/grib_accessor_class_data_simple_packing.h
@@ -29,16 +29,16 @@ public:
     int unpack_double_subarray(double* val, size_t start, size_t len) override;
 
 protected:
-    int edition_;
-    const char* units_factor_;
-    const char* units_bias_;
-    const char* changing_precision_;
-    const char* number_of_values_;
-    const char* bits_per_value_;
-    const char* reference_value_;
-    const char* binary_scale_factor_;
-    const char* decimal_scale_factor_;
-    const char* optimize_scaling_factor_;
+    int edition_ = 0;
+    const char* units_factor_ = nullptr;
+    const char* units_bias_ = nullptr;
+    const char* changing_precision_ = nullptr;
+    const char* number_of_values_ = nullptr;
+    const char* bits_per_value_ = nullptr;
+    const char* reference_value_ = nullptr;
+    const char* binary_scale_factor_ = nullptr;
+    const char* decimal_scale_factor_ = nullptr;
+    const char* optimize_scaling_factor_ = nullptr;
 
 private:
     template <typename T> int unpack(T* val, size_t* len);
diff --git a/src/accessor/grib_accessor_class_decimal_precision.h b/src/accessor/grib_accessor_class_decimal_precision.h
index 493bb500a..d86677589 100644
--- a/src/accessor/grib_accessor_class_decimal_precision.h
+++ b/src/accessor/grib_accessor_class_decimal_precision.h
@@ -23,8 +23,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* bits_per_value_;
-    const char* changing_precision_;
-    const char* decimal_scale_factor_;
+    const char* values_ = nullptr;
+    const char* bits_per_value_ = nullptr;
+    const char* changing_precision_ = nullptr;
+    const char* decimal_scale_factor_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_dictionary.h b/src/accessor/grib_accessor_class_dictionary.h
index 7c6b8ed76..c0096c402 100644
--- a/src/accessor/grib_accessor_class_dictionary.h
+++ b/src/accessor/grib_accessor_class_dictionary.h
@@ -27,11 +27,11 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* dictionary_;
-    const char* key_;
-    long column_;
-    const char* masterDir_;
-    const char* localDir_;
+    const char* dictionary_ = nullptr;
+    const char* key_ = nullptr;
+    long column_ = 0;
+    const char* masterDir_ = nullptr;
+    const char* localDir_ = nullptr;
 
     grib_trie* load_dictionary(int* err);
 };
diff --git a/src/accessor/grib_accessor_class_dirty.h b/src/accessor/grib_accessor_class_dirty.h
index ff10e8a5f..87dbc74c5 100644
--- a/src/accessor/grib_accessor_class_dirty.h
+++ b/src/accessor/grib_accessor_class_dirty.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* accessor_;
+    const char* accessor_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_divdouble.h b/src/accessor/grib_accessor_class_divdouble.h
index ea4a344e4..2366fa5a6 100644
--- a/src/accessor/grib_accessor_class_divdouble.h
+++ b/src/accessor/grib_accessor_class_divdouble.h
@@ -22,6 +22,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* val_;
-    double divisor_;
+    const char* val_ = nullptr;
+    double divisor_ = 0.;
 };
diff --git a/src/accessor/grib_accessor_class_element.h b/src/accessor/grib_accessor_class_element.h
index 4d8d17199..0a93b282d 100644
--- a/src/accessor/grib_accessor_class_element.h
+++ b/src/accessor/grib_accessor_class_element.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* array_;
-    long element_;
+    const char* array_ = nullptr;
+    long element_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_evaluate.h b/src/accessor/grib_accessor_class_evaluate.h
index aa76049bf..cb0403411 100644
--- a/src/accessor/grib_accessor_class_evaluate.h
+++ b/src/accessor/grib_accessor_class_evaluate.h
@@ -22,5 +22,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 protected:
-    grib_arguments* arg_; // expression to be evaluated
+    grib_arguments* arg_ = nullptr; // expression to be evaluated
 };
diff --git a/src/accessor/grib_accessor_class_expanded_descriptors.h b/src/accessor/grib_accessor_class_expanded_descriptors.h
index 571469b3d..b763d6733 100644
--- a/src/accessor/grib_accessor_class_expanded_descriptors.h
+++ b/src/accessor/grib_accessor_class_expanded_descriptors.h
@@ -41,15 +41,15 @@ public:
     bufr_descriptors_array* grib_accessor_expanded_descriptors_get_expanded(int* err);
 
 private:
-    const char* unexpandedDescriptors_;
-    const char* sequence_;
-    const char* expandedName_;
-    const char* tablesAccessorName_;
-    bufr_descriptors_array* expanded_;
-    int rank_;
-    grib_accessor_expanded_descriptors_t* expandedAccessor_;
-    int do_expand_;
-    grib_accessor* tablesAccessor_;
+    const char* unexpandedDescriptors_ = nullptr;
+    const char* sequence_ = nullptr;
+    const char* expandedName_ = nullptr;
+    const char* tablesAccessorName_ = nullptr;
+    bufr_descriptors_array* expanded_ = nullptr;
+    int rank_ = 0;
+    grib_accessor_expanded_descriptors_t* expandedAccessor_ = nullptr;
+    int do_expand_ = 0;
+    grib_accessor* tablesAccessor_ = nullptr;
 
     int expand();
     void __expand(bufr_descriptors_array* unexpanded, bufr_descriptors_array* expanded, change_coding_params* ccp, int* err);
diff --git a/src/accessor/grib_accessor_class_from_scale_factor_scaled_value.h b/src/accessor/grib_accessor_class_from_scale_factor_scaled_value.h
index 2b8e6372a..c14c522f8 100644
--- a/src/accessor/grib_accessor_class_from_scale_factor_scaled_value.h
+++ b/src/accessor/grib_accessor_class_from_scale_factor_scaled_value.h
@@ -25,6 +25,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* scaleFactor_;
-    const char* scaledValue_;
+    const char* scaleFactor_ = nullptr;
+    const char* scaledValue_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1_message_length.h b/src/accessor/grib_accessor_class_g1_message_length.h
index 95335a67e..aef8142a8 100644
--- a/src/accessor/grib_accessor_class_g1_message_length.h
+++ b/src/accessor/grib_accessor_class_g1_message_length.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* sec4_length_;
+    const char* sec4_length_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1_section4_length.h b/src/accessor/grib_accessor_class_g1_section4_length.h
index 5a0eb4ee0..f2c630968 100644
--- a/src/accessor/grib_accessor_class_g1_section4_length.h
+++ b/src/accessor/grib_accessor_class_g1_section4_length.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* total_length_;
+    const char* total_length_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1bitmap.h b/src/accessor/grib_accessor_class_g1bitmap.h
index e7fb884e4..458e0de58 100644
--- a/src/accessor/grib_accessor_class_g1bitmap.h
+++ b/src/accessor/grib_accessor_class_g1bitmap.h
@@ -24,5 +24,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* unusedBits_;
+    const char* unusedBits_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1date.h b/src/accessor/grib_accessor_class_g1date.h
index 9186e2f49..d9eb0a586 100644
--- a/src/accessor/grib_accessor_class_g1date.h
+++ b/src/accessor/grib_accessor_class_g1date.h
@@ -25,8 +25,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 protected:
-    const char* century_;
-    const char* year_;
-    const char* month_;
-    const char* day_;
+    const char* century_ = nullptr;
+    const char* year_ = nullptr;
+    const char* month_ = nullptr;
+    const char* day_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1end_of_interval_monthly.h b/src/accessor/grib_accessor_class_g1end_of_interval_monthly.h
index 28dbfb4a0..a0e0aaa1b 100644
--- a/src/accessor/grib_accessor_class_g1end_of_interval_monthly.h
+++ b/src/accessor/grib_accessor_class_g1end_of_interval_monthly.h
@@ -25,5 +25,5 @@ public:
     int compare(grib_accessor*) override;
 
 private:
-    const char* verifyingMonth_;
+    const char* verifyingMonth_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1forecastmonth.h b/src/accessor/grib_accessor_class_g1forecastmonth.h
index 1d3f8569b..8963103c7 100644
--- a/src/accessor/grib_accessor_class_g1forecastmonth.h
+++ b/src/accessor/grib_accessor_class_g1forecastmonth.h
@@ -24,12 +24,12 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* verification_yearmonth_;
-    const char* base_date_;
-    const char* day_;
-    const char* hour_;
-    const char* fcmonth_;
-    const char* check_;
+    const char* verification_yearmonth_ = nullptr;
+    const char* base_date_ = nullptr;
+    const char* day_ = nullptr;
+    const char* hour_ = nullptr;
+    const char* fcmonth_ = nullptr;
+    const char* check_ = nullptr;
 
     int unpack_long_edition1(long* val, size_t* len);
 };
diff --git a/src/accessor/grib_accessor_class_g1monthlydate.h b/src/accessor/grib_accessor_class_g1monthlydate.h
index a46aa000a..5c9aa4787 100644
--- a/src/accessor/grib_accessor_class_g1monthlydate.h
+++ b/src/accessor/grib_accessor_class_g1monthlydate.h
@@ -22,5 +22,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* date_;
+    const char* date_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_complex.h b/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_complex.h
index 757358d5a..db5159d0c 100644
--- a/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_complex.h
+++ b/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_complex.h
@@ -22,12 +22,12 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* numberOfValues_;
-    const char* bitsPerValue_;
-    const char* offsetBeforeData_;
-    const char* offsetAfterData_;
-    const char* unusedBits_;
-    const char* JS_;
-    const char* KS_;
-    const char* MS_;
+    const char* numberOfValues_ = nullptr;
+    const char* bitsPerValue_ = nullptr;
+    const char* offsetBeforeData_ = nullptr;
+    const char* offsetAfterData_ = nullptr;
+    const char* unusedBits_ = nullptr;
+    const char* JS_ = nullptr;
+    const char* KS_ = nullptr;
+    const char* MS_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_simple.h b/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_simple.h
index 1f7c15a2a..f8188c9d3 100644
--- a/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_simple.h
+++ b/src/accessor/grib_accessor_class_g1number_of_coded_values_sh_simple.h
@@ -22,9 +22,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* numberOfValues_;
-    const char* bitsPerValue_;
-    const char* offsetBeforeData_;
-    const char* offsetAfterData_;
-    const char* unusedBits_;
+    const char* numberOfValues_ = nullptr;
+    const char* bitsPerValue_ = nullptr;
+    const char* offsetBeforeData_ = nullptr;
+    const char* offsetAfterData_ = nullptr;
+    const char* unusedBits_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g1step_range.h b/src/accessor/grib_accessor_class_g1step_range.h
index a76bd520c..9fc147d36 100644
--- a/src/accessor/grib_accessor_class_g1step_range.h
+++ b/src/accessor/grib_accessor_class_g1step_range.h
@@ -33,12 +33,12 @@ protected:
     int grib_g1_step_get_steps(long* start, long* theEnd);
 
 private:
-    const char* p1_;
-    const char* p2_;
-    const char* timeRangeIndicator_;
-    const char* unit_;
-    const char* step_unit_;
-    const char* stepType_;
-    const char* patch_fp_precip_;
-    int error_on_units_;
+    const char* p1_ = nullptr;
+    const char* p2_ = nullptr;
+    const char* timeRangeIndicator_ = nullptr;
+    const char* unit_ = nullptr;
+    const char* step_unit_ = nullptr;
+    const char* stepType_ = nullptr;
+    const char* patch_fp_precip_ = nullptr;
+    int error_on_units_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_g1verificationdate.h b/src/accessor/grib_accessor_class_g1verificationdate.h
index 0b1abf641..d8bd4fbab 100644
--- a/src/accessor/grib_accessor_class_g1verificationdate.h
+++ b/src/accessor/grib_accessor_class_g1verificationdate.h
@@ -22,7 +22,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* date_;
-    const char* time_;
-    const char* step_;
+    const char* date_ = nullptr;
+    const char* time_ = nullptr;
+    const char* step_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2_aerosol.h b/src/accessor/grib_accessor_class_g2_aerosol.h
index 3f02da7a5..6b9c4a957 100644
--- a/src/accessor/grib_accessor_class_g2_aerosol.h
+++ b/src/accessor/grib_accessor_class_g2_aerosol.h
@@ -24,7 +24,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* productDefinitionTemplateNumber_;
-    const char* stepType_;
-    int optical_;
+    const char* productDefinitionTemplateNumber_ = nullptr;
+    const char* stepType_ = nullptr;
+    int optical_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_g2_chemical.h b/src/accessor/grib_accessor_class_g2_chemical.h
index 7ceece9c5..f366e8987 100644
--- a/src/accessor/grib_accessor_class_g2_chemical.h
+++ b/src/accessor/grib_accessor_class_g2_chemical.h
@@ -24,7 +24,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* productDefinitionTemplateNumber_;
-    const char* stepType_;
-    int chemical_type_;
+    const char* productDefinitionTemplateNumber_ = nullptr;
+    const char* stepType_ = nullptr;
+    int chemical_type_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_g2_eps.h b/src/accessor/grib_accessor_class_g2_eps.h
index 646b29349..5a6a7bb9d 100644
--- a/src/accessor/grib_accessor_class_g2_eps.h
+++ b/src/accessor/grib_accessor_class_g2_eps.h
@@ -24,9 +24,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* productDefinitionTemplateNumber_;
-    const char* stream_;
-    const char* type_;
-    const char* stepType_;
-    const char* derivedForecast_;
+    const char* productDefinitionTemplateNumber_ = nullptr;
+    const char* stream_ = nullptr;
+    const char* type_ = nullptr;
+    const char* stepType_ = nullptr;
+    const char* derivedForecast_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2_mars_labeling.h b/src/accessor/grib_accessor_class_g2_mars_labeling.h
index 11c1178c3..ee761cb25 100644
--- a/src/accessor/grib_accessor_class_g2_mars_labeling.h
+++ b/src/accessor/grib_accessor_class_g2_mars_labeling.h
@@ -27,16 +27,16 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    int index_;
-    const char* the_class_;
-    const char* stream_;
-    const char* type_;
-    const char* expver_;
-    const char* typeOfProcessedData_;
-    const char* productDefinitionTemplateNumber_;
-    const char* stepType_;
-    const char* derivedForecast_;
-    const char* typeOfGeneratingProcess_;
+    int index_ = 0;
+    const char* the_class_ = nullptr;
+    const char* stream_ = nullptr;
+    const char* type_ = nullptr;
+    const char* expver_ = nullptr;
+    const char* typeOfProcessedData_ = nullptr;
+    const char* productDefinitionTemplateNumber_ = nullptr;
+    const char* stepType_ = nullptr;
+    const char* derivedForecast_ = nullptr;
+    const char* typeOfGeneratingProcess_ = nullptr;
 
     int extra_set(long val);
 };
diff --git a/src/accessor/grib_accessor_class_g2bitmap.h b/src/accessor/grib_accessor_class_g2bitmap.h
index 0bc1e1cf5..de23a3f3f 100644
--- a/src/accessor/grib_accessor_class_g2bitmap.h
+++ b/src/accessor/grib_accessor_class_g2bitmap.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* numberOfValues_;
+    const char* numberOfValues_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2bitmap_present.h b/src/accessor/grib_accessor_class_g2bitmap_present.h
index a70765c35..516d5191a 100644
--- a/src/accessor/grib_accessor_class_g2bitmap_present.h
+++ b/src/accessor/grib_accessor_class_g2bitmap_present.h
@@ -24,5 +24,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* bitmapIndicator_;
+    const char* bitmapIndicator_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2date.h b/src/accessor/grib_accessor_class_g2date.h
index 93296a4d8..7ac73519d 100644
--- a/src/accessor/grib_accessor_class_g2date.h
+++ b/src/accessor/grib_accessor_class_g2date.h
@@ -24,7 +24,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* year_;
-    const char* month_;
-    const char* day_;
+    const char* year_ = nullptr;
+    const char* month_ = nullptr;
+    const char* day_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2end_step.h b/src/accessor/grib_accessor_class_g2end_step.h
index 18a9a78ee..5fc5d1b27 100644
--- a/src/accessor/grib_accessor_class_g2end_step.h
+++ b/src/accessor/grib_accessor_class_g2end_step.h
@@ -28,24 +28,24 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* start_step_value_;
-    const char* step_units_;
-    const char* year_;
-    const char* month_;
-    const char* day_;
-    const char* hour_;
-    const char* minute_;
-    const char* second_;
-    const char* year_of_end_of_interval_;
-    const char* month_of_end_of_interval_;
-    const char* day_of_end_of_interval_;
-    const char* hour_of_end_of_interval_;
-    const char* minute_of_end_of_interval_;
-    const char* second_of_end_of_interval_;
-    const char* time_range_unit_;
-    const char* time_range_value_;
-    const char* typeOfTimeIncrement_;
-    const char* numberOfTimeRanges_;
+    const char* start_step_value_ = nullptr;
+    const char* step_units_ = nullptr;
+    const char* year_ = nullptr;
+    const char* month_ = nullptr;
+    const char* day_ = nullptr;
+    const char* hour_ = nullptr;
+    const char* minute_ = nullptr;
+    const char* second_ = nullptr;
+    const char* year_of_end_of_interval_ = nullptr;
+    const char* month_of_end_of_interval_ = nullptr;
+    const char* day_of_end_of_interval_ = nullptr;
+    const char* hour_of_end_of_interval_ = nullptr;
+    const char* minute_of_end_of_interval_ = nullptr;
+    const char* second_of_end_of_interval_ = nullptr;
+    const char* time_range_unit_ = nullptr;
+    const char* time_range_value_ = nullptr;
+    const char* typeOfTimeIncrement_ = nullptr;
+    const char* numberOfTimeRanges_ = nullptr;
 
     int unpack_one_time_range_long_(long* val, size_t* len);
     int unpack_one_time_range_double_(double* val, size_t* len);
diff --git a/src/accessor/grib_accessor_class_g2grid.h b/src/accessor/grib_accessor_class_g2grid.h
index 8ec82e7a6..0053608f1 100644
--- a/src/accessor/grib_accessor_class_g2grid.h
+++ b/src/accessor/grib_accessor_class_g2grid.h
@@ -24,12 +24,12 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* latitude_first_;
-    const char* longitude_first_;
-    const char* latitude_last_;
-    const char* longitude_last_;
-    const char* i_increment_;
-    const char* j_increment_;
-    const char* basic_angle_;
-    const char* sub_division_;
+    const char* latitude_first_ = nullptr;
+    const char* longitude_first_ = nullptr;
+    const char* latitude_last_ = nullptr;
+    const char* longitude_last_ = nullptr;
+    const char* i_increment_ = nullptr;
+    const char* j_increment_ = nullptr;
+    const char* basic_angle_ = nullptr;
+    const char* sub_division_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2latlon.h b/src/accessor/grib_accessor_class_g2latlon.h
index b7e5537c7..27c235b0c 100644
--- a/src/accessor/grib_accessor_class_g2latlon.h
+++ b/src/accessor/grib_accessor_class_g2latlon.h
@@ -25,7 +25,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* grid_;
-    int index_;
-    const char* given_;
+    const char* grid_ = nullptr;
+    int index_ = 0;
+    const char* given_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2level.h b/src/accessor/grib_accessor_class_g2level.h
index 50fc6d0d1..f60a8fbd0 100644
--- a/src/accessor/grib_accessor_class_g2level.h
+++ b/src/accessor/grib_accessor_class_g2level.h
@@ -26,8 +26,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* type_first_;
-    const char* scale_first_;
-    const char* value_first_;
-    const char* pressure_units_;
+    const char* type_first_ = nullptr;
+    const char* scale_first_ = nullptr;
+    const char* value_first_ = nullptr;
+    const char* pressure_units_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2lon.h b/src/accessor/grib_accessor_class_g2lon.h
index a781f666a..936d3175a 100644
--- a/src/accessor/grib_accessor_class_g2lon.h
+++ b/src/accessor/grib_accessor_class_g2lon.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* longitude_;
+    const char* longitude_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_g2step_range.h b/src/accessor/grib_accessor_class_g2step_range.h
index ffc1faf42..638f3b6a8 100644
--- a/src/accessor/grib_accessor_class_g2step_range.h
+++ b/src/accessor/grib_accessor_class_g2step_range.h
@@ -29,6 +29,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* start_step_;
-    const char* end_step_;
+    const char* start_step_ = nullptr;
+    const char* end_step_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_gaussian_grid_name.h b/src/accessor/grib_accessor_class_gaussian_grid_name.h
index 5508e6db4..8868c1fbb 100644
--- a/src/accessor/grib_accessor_class_gaussian_grid_name.h
+++ b/src/accessor/grib_accessor_class_gaussian_grid_name.h
@@ -25,7 +25,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* N_;
-    const char* Ni_;
-    const char* isOctahedral_;
+    const char* N_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* isOctahedral_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_gds_is_present.h b/src/accessor/grib_accessor_class_gds_is_present.h
index 36fe2ddf2..c5138ce26 100644
--- a/src/accessor/grib_accessor_class_gds_is_present.h
+++ b/src/accessor/grib_accessor_class_gds_is_present.h
@@ -24,8 +24,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* gds_present_;
-    const char* grid_definition_;
-    const char* bitmap_present_;
-    const char* values_;
+    const char* gds_present_ = nullptr;
+    const char* grid_definition_ = nullptr;
+    const char* bitmap_present_ = nullptr;
+    const char* values_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_getenv.h b/src/accessor/grib_accessor_class_getenv.h
index 089ed328a..bc0892a14 100644
--- a/src/accessor/grib_accessor_class_getenv.h
+++ b/src/accessor/grib_accessor_class_getenv.h
@@ -25,7 +25,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* envvar_;
-    char* value_;
-    const char* default_value_;
+    const char* envvar_ = nullptr;
+    char* value_ = nullptr;
+    const char* default_value_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_global_gaussian.h b/src/accessor/grib_accessor_class_global_gaussian.h
index 6a3517784..0437eaf98 100644
--- a/src/accessor/grib_accessor_class_global_gaussian.h
+++ b/src/accessor/grib_accessor_class_global_gaussian.h
@@ -23,15 +23,15 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* N_;
-    const char* Ni_;
-    const char* di_;
-    const char* latfirst_;
-    const char* lonfirst_;
-    const char* latlast_;
-    const char* lonlast_;
-    const char* plpresent_;
-    const char* pl_;
-    const char* basic_angle_;
-    const char* subdivision_;
+    const char* N_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* di_ = nullptr;
+    const char* latfirst_ = nullptr;
+    const char* lonfirst_ = nullptr;
+    const char* latlast_ = nullptr;
+    const char* lonlast_ = nullptr;
+    const char* plpresent_ = nullptr;
+    const char* pl_ = nullptr;
+    const char* basic_angle_ = nullptr;
+    const char* subdivision_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_group.h b/src/accessor/grib_accessor_class_group.h
index ad6146c61..a5134073b 100644
--- a/src/accessor/grib_accessor_class_group.h
+++ b/src/accessor/grib_accessor_class_group.h
@@ -30,5 +30,5 @@ public:
     int compare(grib_accessor*) override;
 
 private:
-    char endCharacter_;
+    char endCharacter_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_gts_header.h b/src/accessor/grib_accessor_class_gts_header.h
index f1718fb36..4865a0262 100644
--- a/src/accessor/grib_accessor_class_gts_header.h
+++ b/src/accessor/grib_accessor_class_gts_header.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    int gts_offset_;
-    int gts_length_;
+    int gts_offset_ = 0;
+    int gts_length_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_hash_array.h b/src/accessor/grib_accessor_class_hash_array.h
index 69b4bedc8..dd872e130 100644
--- a/src/accessor/grib_accessor_class_hash_array.h
+++ b/src/accessor/grib_accessor_class_hash_array.h
@@ -33,8 +33,8 @@ public:
     int compare(grib_accessor*) override;
 
 private:
-    char* key_;
-    grib_hash_array_value* ha_;
+    char* key_ = nullptr;
+    grib_hash_array_value* ha_ = nullptr;
 
     grib_hash_array_value* find_hash_value(int* err);
 };
diff --git a/src/accessor/grib_accessor_class_ibmfloat.h b/src/accessor/grib_accessor_class_ibmfloat.h
index 4ea6ee337..3479f7f6c 100644
--- a/src/accessor/grib_accessor_class_ibmfloat.h
+++ b/src/accessor/grib_accessor_class_ibmfloat.h
@@ -30,5 +30,5 @@ public:
     int nearest_smaller_value(double, double*) override;
 
 private:
-    grib_arguments* arg_;
+    grib_arguments* arg_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_ieeefloat.h b/src/accessor/grib_accessor_class_ieeefloat.h
index a82f7cce7..f58a38e8b 100644
--- a/src/accessor/grib_accessor_class_ieeefloat.h
+++ b/src/accessor/grib_accessor_class_ieeefloat.h
@@ -28,5 +28,5 @@ public:
     int nearest_smaller_value(double val, double* nearest) override;
 
 private:
-    grib_arguments* arg_;
+    grib_arguments* arg_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_ifs_param.h b/src/accessor/grib_accessor_class_ifs_param.h
index f59fe3bc0..b3f11fa5d 100644
--- a/src/accessor/grib_accessor_class_ifs_param.h
+++ b/src/accessor/grib_accessor_class_ifs_param.h
@@ -25,6 +25,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* paramId_;
-    const char* type_;
+    const char* paramId_ = nullptr;
+    const char* type_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_iterator.h b/src/accessor/grib_accessor_class_iterator.h
index 8fd950570..da0a8d964 100644
--- a/src/accessor/grib_accessor_class_iterator.h
+++ b/src/accessor/grib_accessor_class_iterator.h
@@ -22,6 +22,6 @@ public:
     void dump(grib_dumper* dumper) override;
 
 private:
-    grib_arguments* args_;
+    grib_arguments* args_ = nullptr;
     friend eccodes::geo_iterator::Iterator* eccodes::geo_iterator::gribIteratorNew(const grib_handle*, unsigned long, int*);
 };
diff --git a/src/accessor/grib_accessor_class_julian_date.h b/src/accessor/grib_accessor_class_julian_date.h
index 58ee82d16..0859ca9ba 100644
--- a/src/accessor/grib_accessor_class_julian_date.h
+++ b/src/accessor/grib_accessor_class_julian_date.h
@@ -30,13 +30,13 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* year_;
-    const char* month_;
-    const char* day_;
-    const char* hour_;
-    const char* minute_;
-    const char* second_;
-    const char* ymd_;
-    const char* hms_;
+    const char* year_ = nullptr;
+    const char* month_ = nullptr;
+    const char* day_ = nullptr;
+    const char* hour_ = nullptr;
+    const char* minute_ = nullptr;
+    const char* second_ = nullptr;
+    const char* ymd_ = nullptr;
+    const char* hms_ = nullptr;
     char sep_[5];
 };
diff --git a/src/accessor/grib_accessor_class_julian_day.h b/src/accessor/grib_accessor_class_julian_day.h
index eddcf1509..8d88b3184 100644
--- a/src/accessor/grib_accessor_class_julian_day.h
+++ b/src/accessor/grib_accessor_class_julian_day.h
@@ -27,8 +27,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* date_;
-    const char* hour_;
-    const char* minute_;
-    const char* second_;
+    const char* date_ = nullptr;
+    const char* hour_ = nullptr;
+    const char* minute_ = nullptr;
+    const char* second_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_latitudes.h b/src/accessor/grib_accessor_class_latitudes.h
index cdf852cbd..3cb92088a 100644
--- a/src/accessor/grib_accessor_class_latitudes.h
+++ b/src/accessor/grib_accessor_class_latitudes.h
@@ -24,9 +24,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    long distinct_;
+    const char* values_ = nullptr;
+    long distinct_ = 0;
     double* lats_ = nullptr;
-    long size_;
-    int save_;
+    long size_ = 0;
+    int save_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_latlon_increment.h b/src/accessor/grib_accessor_class_latlon_increment.h
index b9de0ca54..d9d6f7a70 100644
--- a/src/accessor/grib_accessor_class_latlon_increment.h
+++ b/src/accessor/grib_accessor_class_latlon_increment.h
@@ -25,13 +25,13 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* directionIncrementGiven_;
-    const char* directionIncrement_;
-    const char* scansPositively_;
-    const char* first_;
-    const char* last_;
-    const char* numberOfPoints_;
-    const char* angleMultiplier_;
-    const char* angleDivisor_;
-    long isLongitude_;
+    const char* directionIncrementGiven_ = nullptr;
+    const char* directionIncrement_ = nullptr;
+    const char* scansPositively_ = nullptr;
+    const char* first_ = nullptr;
+    const char* last_ = nullptr;
+    const char* numberOfPoints_ = nullptr;
+    const char* angleMultiplier_ = nullptr;
+    const char* angleDivisor_ = nullptr;
+    long isLongitude_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_latlonvalues.h b/src/accessor/grib_accessor_class_latlonvalues.h
index 0fb9d8621..f2f57728f 100644
--- a/src/accessor/grib_accessor_class_latlonvalues.h
+++ b/src/accessor/grib_accessor_class_latlonvalues.h
@@ -24,5 +24,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
+    const char* values_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_local_definition.h b/src/accessor/grib_accessor_class_local_definition.h
index a665a8f88..a9e8d00fe 100644
--- a/src/accessor/grib_accessor_class_local_definition.h
+++ b/src/accessor/grib_accessor_class_local_definition.h
@@ -25,13 +25,13 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* productDefinitionTemplateNumber_;
-    const char* productDefinitionTemplateNumberInternal_;
-    const char* grib2LocalSectionNumber_;
-    const char* type_;
-    const char* stream_;
-    const char* the_class_;
-    const char* eps_;
-    const char* stepType_;
-    const char* derivedForecast_;
+    const char* productDefinitionTemplateNumber_ = nullptr;
+    const char* productDefinitionTemplateNumberInternal_ = nullptr;
+    const char* grib2LocalSectionNumber_ = nullptr;
+    const char* type_ = nullptr;
+    const char* stream_ = nullptr;
+    const char* the_class_ = nullptr;
+    const char* eps_ = nullptr;
+    const char* stepType_ = nullptr;
+    const char* derivedForecast_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_long_vector.h b/src/accessor/grib_accessor_class_long_vector.h
index 0d000df45..4f9ab6c10 100644
--- a/src/accessor/grib_accessor_class_long_vector.h
+++ b/src/accessor/grib_accessor_class_long_vector.h
@@ -26,6 +26,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* vector_;
-    int index_;
+    const char* vector_ = nullptr;
+    int index_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_longitudes.h b/src/accessor/grib_accessor_class_longitudes.h
index 814aeb304..624ebbefe 100644
--- a/src/accessor/grib_accessor_class_longitudes.h
+++ b/src/accessor/grib_accessor_class_longitudes.h
@@ -24,9 +24,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    long distinct_;
-    double* lons_;
-    long size_;
-    int save_;
+    const char* values_ = nullptr;
+    long distinct_ = 0;
+    double* lons_ = nullptr;
+    long size_ = 0;
+    int save_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_lookup.h b/src/accessor/grib_accessor_class_lookup.h
index cbc0bd39c..8b89bfa33 100644
--- a/src/accessor/grib_accessor_class_lookup.h
+++ b/src/accessor/grib_accessor_class_lookup.h
@@ -30,7 +30,7 @@ public:
     int notify_change(grib_accessor*) override;
 
 private:
-    long llength_;
-    long loffset_;
-    grib_expression* real_name_;
+    long llength_ = 0;
+    long loffset_ = 0;
+    grib_expression* real_name_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_mars_param.h b/src/accessor/grib_accessor_class_mars_param.h
index fc8394f06..24a3d0b61 100644
--- a/src/accessor/grib_accessor_class_mars_param.h
+++ b/src/accessor/grib_accessor_class_mars_param.h
@@ -24,7 +24,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* paramId_;
-    const char* table_;
-    const char* param_;
+    const char* paramId_ = nullptr;
+    const char* table_ = nullptr;
+    const char* param_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_mars_step.h b/src/accessor/grib_accessor_class_mars_step.h
index 4d0dd0ec3..f06f92c25 100644
--- a/src/accessor/grib_accessor_class_mars_step.h
+++ b/src/accessor/grib_accessor_class_mars_step.h
@@ -29,6 +29,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* stepRange_;
-    const char* stepType_;
+    const char* stepRange_ = nullptr;
+    const char* stepType_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_md5.h b/src/accessor/grib_accessor_class_md5.h
index ef70687be..6d677415d 100644
--- a/src/accessor/grib_accessor_class_md5.h
+++ b/src/accessor/grib_accessor_class_md5.h
@@ -27,7 +27,7 @@ public:
     int compare(grib_accessor*) override;
 
 private:
-    const char* offset_key_;
-    grib_expression* length_key_;
-    grib_string_list* blocklist_;
+    const char* offset_key_ = nullptr;
+    grib_expression* length_key_ = nullptr;
+    grib_string_list* blocklist_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_multdouble.h b/src/accessor/grib_accessor_class_multdouble.h
index 85f125565..c2dbe3349 100644
--- a/src/accessor/grib_accessor_class_multdouble.h
+++ b/src/accessor/grib_accessor_class_multdouble.h
@@ -23,6 +23,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* val_;
-    double multiplier_;
+    const char* val_ = nullptr;
+    double multiplier_ = 0.;
 };
diff --git a/src/accessor/grib_accessor_class_nearest.h b/src/accessor/grib_accessor_class_nearest.h
index 0781f9132..9a012c349 100644
--- a/src/accessor/grib_accessor_class_nearest.h
+++ b/src/accessor/grib_accessor_class_nearest.h
@@ -22,7 +22,7 @@ public:
     void dump(grib_dumper* dumper) override;
 
 private:
-    grib_arguments* args_;
+    grib_arguments* args_ = nullptr;
 
     friend grib_nearest* grib_nearest_new(const grib_handle* ch, int* error);
 };
diff --git a/src/accessor/grib_accessor_class_number_of_coded_values.h b/src/accessor/grib_accessor_class_number_of_coded_values.h
index f4df0413d..2f8885c3d 100644
--- a/src/accessor/grib_accessor_class_number_of_coded_values.h
+++ b/src/accessor/grib_accessor_class_number_of_coded_values.h
@@ -23,9 +23,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* numberOfValues_;
-    const char* bitsPerValue_;
-    const char* offsetBeforeData_;
-    const char* offsetAfterData_;
-    const char* unusedBits_;
+    const char* numberOfValues_ = nullptr;
+    const char* bitsPerValue_ = nullptr;
+    const char* offsetBeforeData_ = nullptr;
+    const char* offsetAfterData_ = nullptr;
+    const char* unusedBits_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_number_of_points.h b/src/accessor/grib_accessor_class_number_of_points.h
index fd9a16550..087e674b8 100644
--- a/src/accessor/grib_accessor_class_number_of_points.h
+++ b/src/accessor/grib_accessor_class_number_of_points.h
@@ -23,8 +23,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* ni_;
-    const char* nj_;
-    const char* plpresent_;
-    const char* pl_;
+    const char* ni_ = nullptr;
+    const char* nj_ = nullptr;
+    const char* plpresent_ = nullptr;
+    const char* pl_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_number_of_points_gaussian.h b/src/accessor/grib_accessor_class_number_of_points_gaussian.h
index 530f1ad27..b6bbea3b5 100644
--- a/src/accessor/grib_accessor_class_number_of_points_gaussian.h
+++ b/src/accessor/grib_accessor_class_number_of_points_gaussian.h
@@ -23,16 +23,16 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* ni_;
-    const char* nj_;
-    const char* plpresent_;
-    const char* pl_;
-    const char* order_;
-    const char* lat_first_;
-    const char* lon_first_;
-    const char* lat_last_;
-    const char* lon_last_;
-    const char* support_legacy_;
+    const char* ni_ = nullptr;
+    const char* nj_ = nullptr;
+    const char* plpresent_ = nullptr;
+    const char* pl_ = nullptr;
+    const char* order_ = nullptr;
+    const char* lat_first_ = nullptr;
+    const char* lon_first_ = nullptr;
+    const char* lat_last_ = nullptr;
+    const char* lon_last_ = nullptr;
+    const char* support_legacy_ = nullptr;
 
     int unpack_long_new(long* val, size_t* len);
     int unpack_long_with_legacy_support(long* val, size_t* len);
diff --git a/src/accessor/grib_accessor_class_number_of_values.h b/src/accessor/grib_accessor_class_number_of_values.h
index ab9848b18..ad8156ef6 100644
--- a/src/accessor/grib_accessor_class_number_of_values.h
+++ b/src/accessor/grib_accessor_class_number_of_values.h
@@ -23,10 +23,10 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* bitsPerValue_;
-    const char* numberOfPoints_;
-    const char* bitmapPresent_;
-    const char* bitmap_;
-    const char* numberOfCodedValues_;
+    const char* values_ = nullptr;
+    const char* bitsPerValue_ = nullptr;
+    const char* numberOfPoints_ = nullptr;
+    const char* bitmapPresent_ = nullptr;
+    const char* bitmap_ = nullptr;
+    const char* numberOfCodedValues_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_number_of_values_data_raw_packing.h b/src/accessor/grib_accessor_class_number_of_values_data_raw_packing.h
index 0a6d4567a..c5009ac08 100644
--- a/src/accessor/grib_accessor_class_number_of_values_data_raw_packing.h
+++ b/src/accessor/grib_accessor_class_number_of_values_data_raw_packing.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* precision_;
+    const char* values_ = nullptr;
+    const char* precision_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_octahedral_gaussian.h b/src/accessor/grib_accessor_class_octahedral_gaussian.h
index 280788d91..95cb1dfd7 100644
--- a/src/accessor/grib_accessor_class_octahedral_gaussian.h
+++ b/src/accessor/grib_accessor_class_octahedral_gaussian.h
@@ -24,8 +24,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* N_;
-    const char* Ni_;
-    const char* plpresent_;
-    const char* pl_;
+    const char* N_ = nullptr;
+    const char* Ni_ = nullptr;
+    const char* plpresent_ = nullptr;
+    const char* pl_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_octet_number.h b/src/accessor/grib_accessor_class_octet_number.h
index e8d200818..edddb41e4 100644
--- a/src/accessor/grib_accessor_class_octet_number.h
+++ b/src/accessor/grib_accessor_class_octet_number.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* left_;
-    long right_;
+    const char* left_ = nullptr;
+    long right_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_offset_values.h b/src/accessor/grib_accessor_class_offset_values.h
index c1ee0f11f..b7323bb83 100644
--- a/src/accessor/grib_accessor_class_offset_values.h
+++ b/src/accessor/grib_accessor_class_offset_values.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* missingValue_;
+    const char* values_ = nullptr;
+    const char* missingValue_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_optimal_step_units.h b/src/accessor/grib_accessor_class_optimal_step_units.h
index 0d248204e..5653c852a 100644
--- a/src/accessor/grib_accessor_class_optimal_step_units.h
+++ b/src/accessor/grib_accessor_class_optimal_step_units.h
@@ -31,9 +31,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* forecast_time_value_;
-    const char* forecast_time_unit_;
-    const char* time_range_value_;
-    const char* time_range_unit_;
-    long overwriteStepUnits_;
+    const char* forecast_time_value_ = nullptr;
+    const char* forecast_time_unit_ = nullptr;
+    const char* time_range_value_ = nullptr;
+    const char* time_range_unit_ = nullptr;
+    long overwriteStepUnits_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_pack_bufr_values.h b/src/accessor/grib_accessor_class_pack_bufr_values.h
index 3aeaf7750..cc368436f 100644
--- a/src/accessor/grib_accessor_class_pack_bufr_values.h
+++ b/src/accessor/grib_accessor_class_pack_bufr_values.h
@@ -32,5 +32,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    grib_accessor* data_accessor_;
+    grib_accessor* data_accessor_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_packing_type.h b/src/accessor/grib_accessor_class_packing_type.h
index 46590b565..1af109664 100644
--- a/src/accessor/grib_accessor_class_packing_type.h
+++ b/src/accessor/grib_accessor_class_packing_type.h
@@ -26,6 +26,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* packing_type_;
+    const char* values_ = nullptr;
+    const char* packing_type_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_pad.h b/src/accessor/grib_accessor_class_pad.h
index 72b85d8fe..71ad09e17 100644
--- a/src/accessor/grib_accessor_class_pad.h
+++ b/src/accessor/grib_accessor_class_pad.h
@@ -23,5 +23,5 @@ public:
     size_t preferred_size(int) override;
 
 private:
-    grib_expression* expression_;
+    grib_expression* expression_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_padto.h b/src/accessor/grib_accessor_class_padto.h
index 84ecd9623..18a550474 100644
--- a/src/accessor/grib_accessor_class_padto.h
+++ b/src/accessor/grib_accessor_class_padto.h
@@ -24,5 +24,5 @@ public:
     size_t preferred_size(int) override;
 
 private:
-    grib_expression* expression_;
+    grib_expression* expression_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_padtoeven.h b/src/accessor/grib_accessor_class_padtoeven.h
index e9415a3b5..ef605174a 100644
--- a/src/accessor/grib_accessor_class_padtoeven.h
+++ b/src/accessor/grib_accessor_class_padtoeven.h
@@ -23,6 +23,6 @@ public:
     size_t preferred_size(int) override;
 
 private:
-    const char* section_offset_;
-    const char* section_length_;
+    const char* section_offset_ = nullptr;
+    const char* section_length_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_padtomultiple.h b/src/accessor/grib_accessor_class_padtomultiple.h
index 1ba26bf8a..61b4025f2 100644
--- a/src/accessor/grib_accessor_class_padtomultiple.h
+++ b/src/accessor/grib_accessor_class_padtomultiple.h
@@ -23,6 +23,6 @@ public:
     size_t preferred_size(int) override;
 
 private:
-    grib_expression* begin_;
-    grib_expression* multiple_;
+    grib_expression* begin_ = nullptr;
+    grib_expression* multiple_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_proj_string.h b/src/accessor/grib_accessor_class_proj_string.h
index 47d5b41c1..a49773638 100644
--- a/src/accessor/grib_accessor_class_proj_string.h
+++ b/src/accessor/grib_accessor_class_proj_string.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* grid_type_;
-    int endpoint_;
+    const char* grid_type_ = nullptr;
+    int endpoint_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_raw.h b/src/accessor/grib_accessor_class_raw.h
index e933a63be..08394b7be 100644
--- a/src/accessor/grib_accessor_class_raw.h
+++ b/src/accessor/grib_accessor_class_raw.h
@@ -29,7 +29,7 @@ public:
     int compare(grib_accessor*) override;
 
 private:
-    const char* totalLength_;
-    const char* sectionLength_;
-    long relativeOffset_;
+    const char* totalLength_ = nullptr;
+    const char* sectionLength_ = nullptr;
+    long relativeOffset_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_rdbtime_guess_date.h b/src/accessor/grib_accessor_class_rdbtime_guess_date.h
index 999913b3b..2c69253c3 100644
--- a/src/accessor/grib_accessor_class_rdbtime_guess_date.h
+++ b/src/accessor/grib_accessor_class_rdbtime_guess_date.h
@@ -24,9 +24,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* typicalYear_;
-    const char* typicalMonth_;
-    const char* typicalDay_;
-    const char* rdbDay_;
-    long yearOrMonth_;
+    const char* typicalYear_ = nullptr;
+    const char* typicalMonth_ = nullptr;
+    const char* typicalDay_ = nullptr;
+    const char* rdbDay_ = nullptr;
+    long yearOrMonth_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_reference_value_error.h b/src/accessor/grib_accessor_class_reference_value_error.h
index 401714ddb..1a5316820 100644
--- a/src/accessor/grib_accessor_class_reference_value_error.h
+++ b/src/accessor/grib_accessor_class_reference_value_error.h
@@ -23,6 +23,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* referenceValue_;
-    const char* floatType_;
+    const char* referenceValue_ = nullptr;
+    const char* floatType_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_scale.h b/src/accessor/grib_accessor_class_scale.h
index 074b87778..0ddf084bb 100644
--- a/src/accessor/grib_accessor_class_scale.h
+++ b/src/accessor/grib_accessor_class_scale.h
@@ -26,8 +26,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* value_;
-    const char* multiplier_;
-    const char* divisor_;
-    const char* truncating_;
+    const char* value_ = nullptr;
+    const char* multiplier_ = nullptr;
+    const char* divisor_ = nullptr;
+    const char* truncating_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_scale_values.h b/src/accessor/grib_accessor_class_scale_values.h
index bfed5b5fc..054ef46d8 100644
--- a/src/accessor/grib_accessor_class_scale_values.h
+++ b/src/accessor/grib_accessor_class_scale_values.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* missingValue_;
+    const char* values_ = nullptr;
+    const char* missingValue_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_second_order_bits_per_value.h b/src/accessor/grib_accessor_class_second_order_bits_per_value.h
index 5bfac2932..08351480f 100644
--- a/src/accessor/grib_accessor_class_second_order_bits_per_value.h
+++ b/src/accessor/grib_accessor_class_second_order_bits_per_value.h
@@ -24,8 +24,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
-    const char* binaryScaleFactor_;
-    const char* decimalScaleFactor_;
-    long bitsPerValue_;
+    const char* values_ = nullptr;
+    const char* binaryScaleFactor_ = nullptr;
+    const char* decimalScaleFactor_ = nullptr;
+    long bitsPerValue_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_section_padding.h b/src/accessor/grib_accessor_class_section_padding.h
index 6b87449b9..bde1fd3c3 100644
--- a/src/accessor/grib_accessor_class_section_padding.h
+++ b/src/accessor/grib_accessor_class_section_padding.h
@@ -23,5 +23,5 @@ public:
     size_t preferred_size(int) override;
 
 private:
-    int preserve_;
+    int preserve_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_section_pointer.h b/src/accessor/grib_accessor_class_section_pointer.h
index 221a66eb4..1e82b922e 100644
--- a/src/accessor/grib_accessor_class_section_pointer.h
+++ b/src/accessor/grib_accessor_class_section_pointer.h
@@ -26,7 +26,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* sectionOffset_;
-    const char* sectionLength_;
-    long sectionNumber_;
+    const char* sectionOffset_ = nullptr;
+    const char* sectionLength_ = nullptr;
+    long sectionNumber_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_select_step_template.h b/src/accessor/grib_accessor_class_select_step_template.h
index 8dfe2b828..e88b093ee 100644
--- a/src/accessor/grib_accessor_class_select_step_template.h
+++ b/src/accessor/grib_accessor_class_select_step_template.h
@@ -25,6 +25,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* productDefinitionTemplateNumber_;
-    int instant_;
+    const char* productDefinitionTemplateNumber_ = nullptr;
+    int instant_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_signed.h b/src/accessor/grib_accessor_class_signed.h
index 4565dc8ec..08babeb32 100644
--- a/src/accessor/grib_accessor_class_signed.h
+++ b/src/accessor/grib_accessor_class_signed.h
@@ -31,6 +31,6 @@ public:
     void update_size(size_t) override;
 
 private:
-    grib_arguments* arg_;
-    int nbytes_;
+    grib_arguments* arg_ = nullptr;
+    int nbytes_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_signed_bits.h b/src/accessor/grib_accessor_class_signed_bits.h
index e257343e7..79973fa1e 100644
--- a/src/accessor/grib_accessor_class_signed_bits.h
+++ b/src/accessor/grib_accessor_class_signed_bits.h
@@ -29,8 +29,8 @@ public:
     void update_size(size_t) override;
 
 private:
-    const char* numberOfBits_;
-    const char* numberOfElements_;
+    const char* numberOfBits_ = nullptr;
+    const char* numberOfElements_ = nullptr;
 
     long compute_byte_count();
 };
diff --git a/src/accessor/grib_accessor_class_simple_packing_error.h b/src/accessor/grib_accessor_class_simple_packing_error.h
index 25bc3b3b4..4217c8fab 100644
--- a/src/accessor/grib_accessor_class_simple_packing_error.h
+++ b/src/accessor/grib_accessor_class_simple_packing_error.h
@@ -23,9 +23,9 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* binaryScaleFactor_;
-    const char* bitsPerValue_;
-    const char* decimalScaleFactor_;
-    const char* referenceValue_;
-    const char* floatType_;
+    const char* binaryScaleFactor_ = nullptr;
+    const char* bitsPerValue_ = nullptr;
+    const char* decimalScaleFactor_ = nullptr;
+    const char* referenceValue_ = nullptr;
+    const char* floatType_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_size.h b/src/accessor/grib_accessor_class_size.h
index e7689ccc5..b74f7637f 100644
--- a/src/accessor/grib_accessor_class_size.h
+++ b/src/accessor/grib_accessor_class_size.h
@@ -23,5 +23,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* accessor_;
+    const char* accessor_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_smart_table.h b/src/accessor/grib_accessor_class_smart_table.h
index 7e19518e0..bba00b795 100644
--- a/src/accessor/grib_accessor_class_smart_table.h
+++ b/src/accessor/grib_accessor_class_smart_table.h
@@ -30,16 +30,16 @@ public:
     grib_smart_table* smarttable() const { return table_; }
 
 private:
-    grib_smart_table* table_;
-    const char* values_;
-    const char* tablename_;
-    const char* masterDir_;
-    const char* localDir_;
-    const char* extraDir_;
-    const char* extraTable_;
-    int widthOfCode_;
-    long* tableCodes_;
-    size_t tableCodesSize_;
+    grib_smart_table* table_ = nullptr;
+    const char* values_ = nullptr;
+    const char* tablename_ = nullptr;
+    const char* masterDir_ = nullptr;
+    const char* localDir_ = nullptr;
+    const char* extraDir_ = nullptr;
+    const char* extraTable_ = nullptr;
+    int widthOfCode_ = 0;
+    long* tableCodes_ = nullptr;
+    size_t tableCodesSize_ = 0;
 
     grib_smart_table* load_table();
     int get_table_codes();
diff --git a/src/accessor/grib_accessor_class_smart_table_column.h b/src/accessor/grib_accessor_class_smart_table_column.h
index 86b035fb1..f6997e928 100644
--- a/src/accessor/grib_accessor_class_smart_table_column.h
+++ b/src/accessor/grib_accessor_class_smart_table_column.h
@@ -28,6 +28,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* smartTable_;
-    int index_;
+    const char* smartTable_ = nullptr;
+    int index_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_spd.h b/src/accessor/grib_accessor_class_spd.h
index 9c9ecd070..d84424e4d 100644
--- a/src/accessor/grib_accessor_class_spd.h
+++ b/src/accessor/grib_accessor_class_spd.h
@@ -29,8 +29,8 @@ public:
     void update_size(size_t) override;
 
 private:
-    const char* numberOfBits_;
-    const char* numberOfElements_;
+    const char* numberOfBits_ = nullptr;
+    const char* numberOfElements_ = nullptr;
 
     long compute_byte_count();
 };
diff --git a/src/accessor/grib_accessor_class_spectral_truncation.h b/src/accessor/grib_accessor_class_spectral_truncation.h
index e30f7185f..86c4ac5b4 100644
--- a/src/accessor/grib_accessor_class_spectral_truncation.h
+++ b/src/accessor/grib_accessor_class_spectral_truncation.h
@@ -23,8 +23,8 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* J_;
-    const char* K_;
-    const char* M_;
-    const char* T_;
+    const char* J_ = nullptr;
+    const char* K_ = nullptr;
+    const char* M_ = nullptr;
+    const char* T_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_sprintf.h b/src/accessor/grib_accessor_class_sprintf.h
index f64f9601e..a8e87c2f6 100644
--- a/src/accessor/grib_accessor_class_sprintf.h
+++ b/src/accessor/grib_accessor_class_sprintf.h
@@ -25,5 +25,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    grib_arguments* args_;
+    grib_arguments* args_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_statistics.h b/src/accessor/grib_accessor_class_statistics.h
index b64185268..0688092ef 100644
--- a/src/accessor/grib_accessor_class_statistics.h
+++ b/src/accessor/grib_accessor_class_statistics.h
@@ -27,6 +27,6 @@ public:
     int compare(grib_accessor*) override;
 
 private:
-    const char* values_;
-    const char* missing_value_;
+    const char* values_ = nullptr;
+    const char* missing_value_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_statistics_spectral.h b/src/accessor/grib_accessor_class_statistics_spectral.h
index 15f883f54..0ee51837b 100644
--- a/src/accessor/grib_accessor_class_statistics_spectral.h
+++ b/src/accessor/grib_accessor_class_statistics_spectral.h
@@ -26,9 +26,9 @@ public:
     int compare(grib_accessor*) override;
 
 private:
-    const char* values_;
-    const char* J_;
-    const char* K_;
-    const char* M_;
-    const char* JS_;
+    const char* values_ = nullptr;
+    const char* J_ = nullptr;
+    const char* K_ = nullptr;
+    const char* M_ = nullptr;
+    const char* JS_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_step_human_readable.h b/src/accessor/grib_accessor_class_step_human_readable.h
index 789a4b333..373ac9016 100644
--- a/src/accessor/grib_accessor_class_step_human_readable.h
+++ b/src/accessor/grib_accessor_class_step_human_readable.h
@@ -24,6 +24,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* stepUnits_;
-    const char* step_;
+    const char* stepUnits_ = nullptr;
+    const char* step_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_step_in_units.h b/src/accessor/grib_accessor_class_step_in_units.h
index 49c3403e0..fc6a2963c 100644
--- a/src/accessor/grib_accessor_class_step_in_units.h
+++ b/src/accessor/grib_accessor_class_step_in_units.h
@@ -29,11 +29,11 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* forecast_time_value_;
-    const char* forecast_time_unit_;
-    const char* step_units_;
-    const char* time_range_unit_;
-    const char* time_range_value_;
+    const char* forecast_time_value_ = nullptr;
+    const char* forecast_time_unit_ = nullptr;
+    const char* step_units_ = nullptr;
+    const char* time_range_unit_ = nullptr;
+    const char* time_range_value_ = nullptr;
 
     int pack_long_new_(const long start_step_value, const long start_step_unit, const long force_step_units);
 };
diff --git a/src/accessor/grib_accessor_class_sum.h b/src/accessor/grib_accessor_class_sum.h
index 1ea5dfeed..ef49a7289 100644
--- a/src/accessor/grib_accessor_class_sum.h
+++ b/src/accessor/grib_accessor_class_sum.h
@@ -25,5 +25,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* values_;
+    const char* values_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_suppressed.h b/src/accessor/grib_accessor_class_suppressed.h
index 2fce6dc51..b162a74da 100644
--- a/src/accessor/grib_accessor_class_suppressed.h
+++ b/src/accessor/grib_accessor_class_suppressed.h
@@ -27,7 +27,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    grib_arguments* args_;
+    grib_arguments* args_ = nullptr;
 
     void log_message();
 };
diff --git a/src/accessor/grib_accessor_class_time.h b/src/accessor/grib_accessor_class_time.h
index dfa439ee2..52b3df90d 100644
--- a/src/accessor/grib_accessor_class_time.h
+++ b/src/accessor/grib_accessor_class_time.h
@@ -24,7 +24,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* hour_;
-    const char* minute_;
-    const char* second_;
+    const char* hour_ = nullptr;
+    const char* minute_ = nullptr;
+    const char* second_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_to_double.h b/src/accessor/grib_accessor_class_to_double.h
index cbf3af18a..d3bcf3c17 100644
--- a/src/accessor/grib_accessor_class_to_double.h
+++ b/src/accessor/grib_accessor_class_to_double.h
@@ -29,10 +29,10 @@ public:
     void init(const long, grib_arguments*) override;
 
 protected:
-    const char* key_;
-    long start_;
-    size_t str_length_;
+    const char* key_ = nullptr;
+    long start_ = 0;
+    size_t str_length_ = 0;
 
 private:
-    long scale_;
+    long scale_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_to_integer.h b/src/accessor/grib_accessor_class_to_integer.h
index e50eebbfa..147cf4d08 100644
--- a/src/accessor/grib_accessor_class_to_integer.h
+++ b/src/accessor/grib_accessor_class_to_integer.h
@@ -32,7 +32,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* key_;
-    long start_;
-    size_t str_length_;
+    const char* key_ = nullptr;
+    long start_ = 0;
+    size_t str_length_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_to_string.h b/src/accessor/grib_accessor_class_to_string.h
index 09385eb51..4f2af227e 100644
--- a/src/accessor/grib_accessor_class_to_string.h
+++ b/src/accessor/grib_accessor_class_to_string.h
@@ -29,7 +29,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* key_;
-    long start_;
-    size_t str_length_;
+    const char* key_ = nullptr;
+    long start_ = 0;
+    size_t str_length_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_transient_darray.h b/src/accessor/grib_accessor_class_transient_darray.h
index 9c30fb7a0..12abf029f 100644
--- a/src/accessor/grib_accessor_class_transient_darray.h
+++ b/src/accessor/grib_accessor_class_transient_darray.h
@@ -30,6 +30,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    grib_darray* arr_;
-    int type_;
+    grib_darray* arr_ = nullptr;
+    int type_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_trim.h b/src/accessor/grib_accessor_class_trim.h
index 34337ee48..39bc5e97b 100644
--- a/src/accessor/grib_accessor_class_trim.h
+++ b/src/accessor/grib_accessor_class_trim.h
@@ -24,7 +24,7 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* input_;
-    int trim_left_;
-    int trim_right_;
+    const char* input_ = nullptr;
+    int trim_left_ = 0;
+    int trim_right_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_unexpanded_descriptors.h b/src/accessor/grib_accessor_class_unexpanded_descriptors.h
index bc25ef6e4..a3146c4a7 100644
--- a/src/accessor/grib_accessor_class_unexpanded_descriptors.h
+++ b/src/accessor/grib_accessor_class_unexpanded_descriptors.h
@@ -27,6 +27,6 @@ public:
     void update_size(size_t) override;
 
 private:
-    grib_accessor* unexpandedDescriptorsEncoded_;
-    const char* createNewData_;
+    grib_accessor* unexpandedDescriptorsEncoded_ = nullptr;
+    const char* createNewData_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_unpack_bufr_values.h b/src/accessor/grib_accessor_class_unpack_bufr_values.h
index f3e38ad64..07001cd26 100644
--- a/src/accessor/grib_accessor_class_unpack_bufr_values.h
+++ b/src/accessor/grib_accessor_class_unpack_bufr_values.h
@@ -32,5 +32,5 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    grib_accessor_bufr_data_array_t* data_accessor_;
+    grib_accessor_bufr_data_array_t* data_accessor_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_unsigned.h b/src/accessor/grib_accessor_class_unsigned.h
index ef25596b9..7be47f6f4 100644
--- a/src/accessor/grib_accessor_class_unsigned.h
+++ b/src/accessor/grib_accessor_class_unsigned.h
@@ -31,11 +31,11 @@ public:
     void destroy(grib_context* context) override;
 
 protected:
-    long nbytes_;
+    long nbytes_ = 0;
 
     int pack_long_unsigned_helper(const long* val, size_t* len, int check);
 
 private:
-    grib_arguments* arg_;
+    grib_arguments* arg_ = nullptr;
 
 };
diff --git a/src/accessor/grib_accessor_class_unsigned_bits.h b/src/accessor/grib_accessor_class_unsigned_bits.h
index 7de4ed0c4..2469250e8 100644
--- a/src/accessor/grib_accessor_class_unsigned_bits.h
+++ b/src/accessor/grib_accessor_class_unsigned_bits.h
@@ -28,8 +28,8 @@ public:
     void update_size(size_t) override;
 
 private:
-    const char* numberOfBits_;
-    const char* numberOfElements_;
+    const char* numberOfBits_ = nullptr;
+    const char* numberOfElements_ = nullptr;
 
     long compute_byte_count();
 };
diff --git a/src/accessor/grib_accessor_class_validity_date.h b/src/accessor/grib_accessor_class_validity_date.h
index b394503e7..7393eabd9 100644
--- a/src/accessor/grib_accessor_class_validity_date.h
+++ b/src/accessor/grib_accessor_class_validity_date.h
@@ -22,11 +22,11 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* date_;
-    const char* time_;
-    const char* step_;
-    const char* stepUnits_;
-    const char* year_;
-    const char* month_;
-    const char* day_;
+    const char* date_ = nullptr;
+    const char* time_ = nullptr;
+    const char* step_ = nullptr;
+    const char* stepUnits_ = nullptr;
+    const char* year_ = nullptr;
+    const char* month_ = nullptr;
+    const char* day_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_validity_time.h b/src/accessor/grib_accessor_class_validity_time.h
index 2c72ebd83..620900b3c 100644
--- a/src/accessor/grib_accessor_class_validity_time.h
+++ b/src/accessor/grib_accessor_class_validity_time.h
@@ -23,10 +23,10 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* date_;
-    const char* time_;
-    const char* step_;
-    const char* stepUnits_;
-    const char* hours_;
-    const char* minutes_;
+    const char* date_ = nullptr;
+    const char* time_ = nullptr;
+    const char* step_ = nullptr;
+    const char* stepUnits_ = nullptr;
+    const char* hours_ = nullptr;
+    const char* minutes_ = nullptr;
 };
diff --git a/src/accessor/grib_accessor_class_values.h b/src/accessor/grib_accessor_class_values.h
index b8c30cd65..a0d50c234 100644
--- a/src/accessor/grib_accessor_class_values.h
+++ b/src/accessor/grib_accessor_class_values.h
@@ -29,11 +29,11 @@ public:
     int compare(grib_accessor*) override;
 
 protected:
-    int carg_;
-    const char* seclen_;
-    const char* offsetdata_;
-    const char* offsetsection_;
-    int values_dirty_;
+    int carg_ = 0;
+    const char* seclen_ = nullptr;
+    const char* offsetdata_ = nullptr;
+    const char* offsetsection_ = nullptr;
+    int values_dirty_ = 0;
 
 private:
     long init_length();
diff --git a/src/accessor/grib_accessor_class_variable.h b/src/accessor/grib_accessor_class_variable.h
index 29f42cf3a..3c05887ef 100644
--- a/src/accessor/grib_accessor_class_variable.h
+++ b/src/accessor/grib_accessor_class_variable.h
@@ -39,9 +39,9 @@ public:
 
     void accessor_variable_set_type(int type);
 private:
-    double dval_;
-    float fval_;
-    char* cval_;
-    char* cname_;
-    int type_;
+    double dval_ = 0.;
+    float fval_ = 0.f;
+    char* cval_ = nullptr;
+    char* cname_ = nullptr;
+    int type_ = 0;
 };
diff --git a/src/accessor/grib_accessor_class_vector.h b/src/accessor/grib_accessor_class_vector.h
index e3bea93b1..2d3a44cf7 100644
--- a/src/accessor/grib_accessor_class_vector.h
+++ b/src/accessor/grib_accessor_class_vector.h
@@ -22,6 +22,6 @@ public:
     void init(const long, grib_arguments*) override;
 
 private:
-    const char* vector_;
-    int index_;
+    const char* vector_ = nullptr;
+    int index_ = 0;
 };
diff --git a/src/geo_iterator/grib_iterator.h b/src/geo_iterator/grib_iterator.h
index ac87d9005..1eac6ff21 100644
--- a/src/geo_iterator/grib_iterator.h
+++ b/src/geo_iterator/grib_iterator.h
@@ -30,14 +30,14 @@ public:
     virtual bool has_next() const                         = 0;
     virtual Iterator* create() const                      = 0;
 
-    unsigned long flags_;
+    unsigned long flags_ = 0;
 
 protected:
-    grib_handle* h_;
-    double* data_;   /**  data values */
-    mutable long e_; /**  current element */
-    size_t nv_;      /**  number of values */
-    const char* class_name_;
+    grib_handle* h_ = nullptr;
+    double* data_ = nullptr;   /**  data values */
+    mutable long e_ = 0; /**  current element */
+    size_t nv_ = 0;      /**  number of values */
+    const char* class_name_ = nullptr;
 };
 
 eccodes::geo_iterator::Iterator* gribIteratorNew(const grib_handle*, unsigned long, int*);
diff --git a/src/geo_iterator/grib_iterator_class_gaussian_reduced.h b/src/geo_iterator/grib_iterator_class_gaussian_reduced.h
index dbc334423..815a3a4be 100644
--- a/src/geo_iterator/grib_iterator_class_gaussian_reduced.h
+++ b/src/geo_iterator/grib_iterator_class_gaussian_reduced.h
@@ -26,11 +26,11 @@ public:
     int destroy() override;
 
 private:
-    long isRotated_;
-    double angleOfRotation_;
-    double southPoleLat_;
-    double southPoleLon_;
-    long disableUnrotate_;
+    long isRotated_ = 0;
+    double angleOfRotation_ = 0.;
+    double southPoleLat_ = 0.;
+    double southPoleLon_ = 0.;
+    long disableUnrotate_ = 0;
 
     int iterate_reduced_gaussian_subarea_legacy(grib_handle*,
                                                 double, double,
diff --git a/src/geo_iterator/grib_iterator_class_gen.h b/src/geo_iterator/grib_iterator_class_gen.h
index 26ea19b9b..385f6bd16 100644
--- a/src/geo_iterator/grib_iterator_class_gen.h
+++ b/src/geo_iterator/grib_iterator_class_gen.h
@@ -29,9 +29,9 @@ public:
     bool has_next() const override;
 
 protected:
-    int carg_;
-    double* lats_;
-    double* lons_;
+    int carg_ = 0;
+    double* lats_ = nullptr;
+    double* lons_ = nullptr;
 
 private:
     //int get(double*, double*, double*);
diff --git a/src/geo_iterator/grib_iterator_class_healpix.h b/src/geo_iterator/grib_iterator_class_healpix.h
index 2760ef9b7..851dbb472 100644
--- a/src/geo_iterator/grib_iterator_class_healpix.h
+++ b/src/geo_iterator/grib_iterator_class_healpix.h
@@ -26,8 +26,8 @@ public:
     int destroy() override;
 
 private:
-    // long Nsides_;
-    bool nested_;
+    // long Nsides_ = 0;
+    bool nested_ = false;
 
     int iterate_healpix(long N);
 };
diff --git a/src/geo_iterator/grib_iterator_class_regular.h b/src/geo_iterator/grib_iterator_class_regular.h
index b7d5bfd34..428397b42 100644
--- a/src/geo_iterator/grib_iterator_class_regular.h
+++ b/src/geo_iterator/grib_iterator_class_regular.h
@@ -26,15 +26,15 @@ public:
     int destroy() override;
 
 protected:
-    long Ni_;
-    long Nj_;
-    long iScansNegatively_;
-    long isRotated_;
-    double angleOfRotation_;
-    double southPoleLat_;
-    double southPoleLon_;
-    long jPointsAreConsecutive_;
-    long disableUnrotate_;
+    long Ni_ = 0;
+    long Nj_ = 0;
+    long iScansNegatively_ = 0;
+    long isRotated_ = 0;
+    double angleOfRotation_ = 0.;
+    double southPoleLat_ = 0.;
+    double southPoleLon_ = 0.;
+    long jPointsAreConsecutive_ = 0;
+    long disableUnrotate_ = 0;
 };
 
 }  // namespace eccodes::geo_iterator