libstdc++-v3/testsuite/20_util/is_nothrow_invocable/91456.cc

// Copyright (C) 2019-2025 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-do compile { target c++17 } }

// PR 91456
// std::function and std::is_invocable_r do not understand guaranteed elision

#include <type_traits>

#include <functional>

struct Immovable {
  Immovable() = default;
  Immovable(const Immovable&) = delete;
  Immovable& operator=(const Immovable&) = delete;
};

static_assert(std::is_nothrow_invocable_r_v<Immovable, Immovable(*)() noexcept>);
static_assert(std::is_nothrow_invocable_r_v<const Immovable, Immovable(*)() noexcept>);
static_assert(std::is_nothrow_invocable_r_v<Immovable, const Immovable(*)() noexcept>);