overflow.h File Reference

#include <util/check.h>
#include <climits>
#include <concepts>
#include <limits>
#include <optional>
#include <type_traits>

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Functions
template<std::integral T>
bool	AdditionOverflow (const T i, const T j) noexcept
template<class T>
std::optional< T >	CheckedAdd (const T i, const T j) noexcept
template<std::unsigned_integral T, std::unsigned_integral U>
constexpr bool	TrySub (T &i, const U j) noexcept
template<std::integral T>
T	SaturatingAdd (const T i, const T j) noexcept
template<std::unsigned_integral Dividend, std::unsigned_integral Divisor>
constexpr auto	CeilDiv (const Dividend dividend, const Divisor divisor)
	Integer ceiling division (for unsigned values).
template<std::integral T>
constexpr std::optional< T >	CheckedLeftShift (T input, unsigned shift) noexcept
	Left bit shift with overflow checking.
template<std::integral T>
constexpr T	SaturatingLeftShift (T input, unsigned shift) noexcept
	Left bit shift with safe minimum and maximum values.

Function Documentation

AdditionOverflow()

template<std::integral T>

bool AdditionOverflow ( const T i, const T j )

nodiscardnoexcept

Definition at line 17 of file overflow.h.

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CeilDiv()

template<std::unsigned_integral Dividend, std::unsigned_integral Divisor>

auto CeilDiv ( const Dividend dividend, const Divisor divisor )

nodiscardconstexpr

Integer ceiling division (for unsigned values).

Computes the smallest integer q such that q * divisor >= dividend. Both dividend and divisor must be unsigned, and divisor must be non-zero.

The implementation avoids overflow that can occur with (dividend + divisor - 1) / divisor.

Definition at line 70 of file overflow.h.

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CheckedAdd()

template<class T>

std::optional< T > CheckedAdd ( const T i, const T j )

nodiscardnoexcept

Definition at line 27 of file overflow.h.

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CheckedLeftShift()

template<std::integral T>

std::optional< T > CheckedLeftShift ( T input, unsigned shift )

constexprnoexcept

Left bit shift with overflow checking.

Parameters

input	The input value to be left shifted.
shift	The number of bits to left shift.

Returns

(input * 2^shift) or nullopt if it would not fit in the return type.

Definition at line 83 of file overflow.h.

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SaturatingAdd()

template<std::integral T>

T SaturatingAdd ( const T i, const T j )

nodiscardnoexcept

Definition at line 44 of file overflow.h.

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SaturatingLeftShift()

template<std::integral T>

T SaturatingLeftShift ( T input, unsigned shift )

constexprnoexcept

Left bit shift with safe minimum and maximum values.

Parameters

input	The input value to be left shifted.
shift	The number of bits to left shift.

Returns

(input * 2^shift) clamped to fit between the lowest and highest representable values of the type T.

Definition at line 102 of file overflow.h.

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TrySub()

template<std::unsigned_integral T, std::unsigned_integral U>

bool TrySub ( T & i, const U j )

nodiscardconstexprnoexcept

Definition at line 36 of file overflow.h.

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