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ECC-1930: Cleanup

This commit is contained in:
Eugen Betke 2024-10-09 08:53:15 +00:00 committed by shahramn
parent f0b40ca4d4
commit 5f5ae2056f
1 changed files with 30 additions and 40 deletions
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70
src/NumericLimits.h
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@ -11,15 +11,21 @@
#pragma once
#include <array>
#include <cstdint>
#include <climits> // CHAR_BIT
#include <climits> // CHAR_BIT
// NumericLimits is a class template that provides the minimum and maximum values for a given number of bits.
// The minimum and maximum values are calculated for both signed and unsigned integral types.
template <typename ValueType, bool = std::is_signed<ValueType>::value, bool = std::is_integral<ValueType>::value>
struct NumericLimits
{
static_assert(std::is_integral<ValueType>::value, "ValueType must be an integral type");
};
// Example:
// For a 16-bit signed integer, the minimum and maximum values are:
// nbits | min | max
// nBits | min | max
// ----- | --- | ---
// 1 | -1 | 0
// 2 | -2 | 1
@ -29,47 +35,40 @@
// 15 | -16384 | 16383
// 16 | -32768 | 32767
template <typename ValueType, bool = std::is_signed<ValueType>::value, bool = std::is_integral<ValueType>::value>
struct NumericLimits
template <typename ValueType>
struct NumericLimits<ValueType, true, true>
{
private:
static constexpr uint8_t MaxN = CHAR_BIT * sizeof(ValueType);
static constexpr std::size_t maxNBits = CHAR_BIT * sizeof(ValueType);
static constexpr std::array<ValueType, MaxN> max_ = []() {
std::array<ValueType, MaxN> max{};
static constexpr std::array<ValueType, maxNBits> max_ = []() {
std::array<ValueType, maxNBits> max{};
using UnsignedValueType = std::make_unsigned_t<ValueType>;
constexpr UnsignedValueType ones = ~UnsignedValueType{0};
constexpr UnsignedValueType ones = ~UnsignedValueType{ 0 };
max[0] = 0;
for (uint8_t i = 1; i < MaxN; ++i) {
max[i] = static_cast<ValueType>(ones >> (MaxN - i));
for (std::size_t i = 1; i < maxNBits; ++i) {
max[i] = static_cast<ValueType>(ones >> (maxNBits - i));
}
return max;
}();
static constexpr std::array<ValueType, MaxN> min_ = []() {
std::array<ValueType, MaxN> min{};
for (uint8_t i = 0; i < MaxN; ++i) {
static constexpr std::array<ValueType, maxNBits> min_ = []() {
std::array<ValueType, maxNBits> min{};
for (std::size_t i = 0; i < maxNBits; ++i) {
min[i] = ~max_[i];
}
return min;
}();
public:
static constexpr ValueType min(uint8_t nbits)
{
return min_[nbits - 1];
}
static constexpr ValueType max(uint8_t nbits)
{
return max_[nbits - 1];
}
static constexpr ValueType min(std::size_t nBits) { return min_[nBits - 1]; }
static constexpr ValueType max(std::size_t nBits) { return max_[nBits - 1]; }
};
// Example:
// For a 16-bit unsigned integer, the minimum and maximum values are:
// nbits | min | max
// nBits | min | max
// ----- | --- | ---
// 1 | 0 | 1
// 2 | 0 | 3
@ -82,29 +81,20 @@ public:
template <typename ValueType>
struct NumericLimits<ValueType, false, true>
{
static_assert(std::is_integral<ValueType>::value, "ValueType must be an integral type");
private:
static constexpr uint8_t MaxN = CHAR_BIT * sizeof(ValueType);
static constexpr std::size_t maxNBits = CHAR_BIT * sizeof(ValueType);
static constexpr std::array<ValueType, MaxN> max_ = []() {
std::array<ValueType, MaxN> max{};
static constexpr std::array<ValueType, maxNBits> max_ = []() {
std::array<ValueType, maxNBits> max{};
constexpr ValueType ones = ~(static_cast<ValueType>(0));
max[0] = 1;
for (uint8_t i = 1; i < MaxN; ++i) {
max[i] = ones >> (MaxN - i - 1);
for (std::size_t i = 1; i < maxNBits; ++i) {
max[i] = ones >> (maxNBits - i - 1);
}
return max;
}();
public:
static constexpr ValueType min(uint8_t nbits)
{
return 0;
}
static constexpr ValueType max(uint8_t nbits)
{
return max_[nbits - 1];
}
static constexpr ValueType min(std::size_t nBits) { return 0; }
static constexpr ValueType max(std::size_t nBits) { return max_[nBits - 1]; }
};