algorithm/internal/absolute.hpp

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• Last update: 2025-08-23 10:05:58+00:00
• Include: #include "algorithm/internal/absolute.hpp"

Required by

• Greatest Common Divisor（最大公約数） (algorithm/Math/NumberTheory/greatest_common_divisor.hpp)
• Least Common Multiple（最小公倍数） (algorithm/Math/NumberTheory/least_common_multiple.hpp)

Verified with

• verify/aoj-NTL_1_C-least_common_multiple.test.cpp

Code

#ifndef ALGORITHM_ABSOLUTE_HPP
#define ALGORITHM_ABSOLUTE_HPP 1

#include <concepts>
#include <type_traits>

namespace algorithm {

namespace internal {

// Returns the absolute value as type Res.
template <std::integral Res, std::unsigned_integral Type>
constexpr Res abs(Type n) {
    static_assert(sizeof(Res) >= sizeof(Type));
    return static_cast<Res>(n);
}

// Returns the absolute value as type Res.
template <std::integral Res, std::signed_integral Type>
constexpr Res abs(Type n) {
    static_assert(sizeof(Res) >= sizeof(Type));
    return static_cast<Res>(std::make_unsigned_t<Type>(n < 0 ? -n : n));
}

}  // namespace internal

}  // namespace algorithm

#endif

#line 1 "algorithm/internal/absolute.hpp"



#include <concepts>
#include <type_traits>

namespace algorithm {

namespace internal {

// Returns the absolute value as type Res.
template <std::integral Res, std::unsigned_integral Type>
constexpr Res abs(Type n) {
    static_assert(sizeof(Res) >= sizeof(Type));
    return static_cast<Res>(n);
}

// Returns the absolute value as type Res.
template <std::integral Res, std::signed_integral Type>
constexpr Res abs(Type n) {
    static_assert(sizeof(Res) >= sizeof(Type));
    return static_cast<Res>(std::make_unsigned_t<Type>(n < 0 ? -n : n));
}

}  // namespace internal

}  // namespace algorithm

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