// Copyright (C) 2019-2023 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3.  If not see
// <http://www.gnu.org/licenses/>.

// { dg-options "-std=gnu++2a" }
// { dg-do compile { target c++2a } }

#include <functional>

struct F
{
  int i;
  constexpr int add(int j) { return i + j; }
};

constexpr int
test01(int i)
{
  F f{i};
  return std::mem_fn(&F::i)(f);
}

static_assert( test01(2) == 2 );

constexpr int
test02(int i, int j)
{
  F f{i};
  return std::mem_fn(&F::add)(&f, j);
}

static_assert( test02(3, 4) == 7 );