lib_math

/* File: /cpp/lib_math
 *
 * This file is a part of cpplib project which is distributed under MIT License.
 * See file LICENSE for full license details.
 *
 * Copyright (c) 2020-present Nikita Zuev (V.Slavski!) <nikita.zuev@gmx.com>
 */
#ifndef CPPLIB__cpp__lib_math
#define CPPLIB__cpp__lib_math

#include <cmath>

#include <limits>

#include "lib_concepts"

namespace cpp {

/** @copyright As the original source code was taken from [cppreference.com](https://cppreference.com/) site, source
 *  code of this function is distributed under [CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/) license.
 *  @see https://en.cppreference.com/w/cpp/types/numeric_limits/epsilon
 */

template< FloatingPoint T >
inline constexpr bool epsilon_eq( T a, T b, int ulp = 1 ) noexcept {
	const auto diff = ::std::abs( a - b );
	const auto epsilon = ::std::numeric_limits<T>::epsilon() * ::std::abs( a + b ) * (T) ulp;
	return diff <= epsilon || diff < ::std::numeric_limits<T>::min();
}

} // namespace cpp

#endif // CPPLIB__cpp__lib_math