// -*- C++ -*-
//===------------------------ propagate_const -----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST
#define _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST
/*
    propagate_const synopsis

    namespace std { namespace experimental { inline namespace fundamentals_v2 {

    // [propagate_const]
    template <class T> class propagate_const;

    // [propagate_const.underlying], underlying pointer access
    constexpr const _Tp& _VSTD_LFTS_V2::get_underlying(const propagate_const<T>& pt) noexcept;
    constexpr T& _VSTD_LFTS_V2::get_underlying(propagate_const<T>& pt) noexcept;

    // [propagate_const.relational], relational operators
    template <class T> constexpr bool operator==(const propagate_const<T>& pt, nullptr_t);
    template <class T> constexpr bool operator==(nullptr_t, const propagate_const<T>& pu);
    template <class T> constexpr bool operator!=(const propagate_const<T>& pt, nullptr_t);
    template <class T> constexpr bool operator!=(nullptr_t, const propagate_const<T>& pu);
    template <class T, class U> constexpr bool operator==(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
    template <class T, class U> constexpr bool operator!=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
    template <class T, class U> constexpr bool operator<(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
    template <class T, class U> constexpr bool operator>(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
    template <class T, class U> constexpr bool operator<=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
    template <class T, class U> constexpr bool operator>=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
    template <class T, class U> constexpr bool operator==(const propagate_const<T>& pt, const _Up& u);
    template <class T, class U> constexpr bool operator!=(const propagate_const<T>& pt, const _Up& u);
    template <class T, class U> constexpr bool operator<(const propagate_const<T>& pt, const _Up& u);
    template <class T, class U> constexpr bool operator>(const propagate_const<T>& pt, const _Up& u);
    template <class T, class U> constexpr bool operator<=(const propagate_const<T>& pt, const _Up& u);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   