is_same_function.hpp

/*
 * mstd - Maipa's Standard Library
 *
 * Licensed under the BSD 3-Clause License with Attribution Requirement.
 * See the LICENSE file for details: https://github.com/MAIPA01/mstd/blob/main/LICENSE
 *
 * Copyright (c) 2025, Patryk Antosik (MAIPA01)
 */
 
#pragma once
#ifndef _MSTD_IS_SAME_FUNCTION_HPP_
    #define _MSTD_IS_SAME_FUNCTION_HPP_
 
    #include <mstd/config.hpp>
 
    #if !_MSTD_HAS_CXX17
_MSTD_WARNING("this is only available for c++17 and greater!");
    #else
 
        #include <mstd/functions_types.hpp>
 
namespace mstd {
    // Checking If functions are same
    template<class Fa, class Fb, class = void>
    struct is_same_function : std::false_type {};
 
    template<class F>
    struct is_same_function<F, F, std::void_t<std::enable_if_t<is_function_v<F> > > > : std::true_type {};
 
    template<class Fa, class Fb>
    struct is_same_function<Fa, Fb, std::void_t<as_std_function_t<Fa>, as_std_function_t<Fb> > >
        : std::is_same<as_std_function_t<Fa>, as_std_function_t<Fb> > {};
 
    template<class Fa, class Fb>
    _MSTD_CONSTEXPR17 bool is_same_function_v = is_same_function<Fa, Fb>::value;
 
        #if _MSTD_HAS_CXX20
    template<class Fa, class Fb> concept same_function_as = is_same_function_v<Fa, Fb>;
        #endif
} // namespace mstd
    #endif
#endif