llvm-project/libcxx/test/support/is_transparent.h

74 lines
2.3 KiB
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef TRANSPARENT_H
#define TRANSPARENT_H
// testing transparent
#if _LIBCPP_STD_VER > 11
struct transparent_less
{
template <class T, class U>
constexpr auto operator()(T&& t, U&& u) const
noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u)))
-> decltype (std::forward<T>(t) < std::forward<U>(u))
{ return std::forward<T>(t) < std::forward<U>(u); }
typedef void is_transparent; // correct
};
struct transparent_less_no_type
{
template <class T, class U>
constexpr auto operator()(T&& t, U&& u) const
noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u)))
-> decltype (std::forward<T>(t) < std::forward<U>(u))
{ return std::forward<T>(t) < std::forward<U>(u); }
private:
// typedef void is_transparent; // error - should exist
};
struct transparent_less_private
{
template <class T, class U>
constexpr auto operator()(T&& t, U&& u) const
noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u)))
-> decltype (std::forward<T>(t) < std::forward<U>(u))
{ return std::forward<T>(t) < std::forward<U>(u); }
private:
typedef void is_transparent; // error - should be accessible
};
struct transparent_less_not_a_type
{
template <class T, class U>
constexpr auto operator()(T&& t, U&& u) const
noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u)))
-> decltype (std::forward<T>(t) < std::forward<U>(u))
{ return std::forward<T>(t) < std::forward<U>(u); }
int is_transparent; // error - should be a type
};
struct C2Int { // comparable to int
C2Int() : i_(0) {}
C2Int(int i): i_(i) {}
int get () const { return i_; }
private:
int i_;
};
bool operator <(int rhs, const C2Int& lhs) { return rhs < lhs.get(); }
bool operator <(const C2Int& rhs, const C2Int& lhs) { return rhs.get() < lhs.get(); }
bool operator <(const C2Int& rhs, int lhs) { return rhs.get() < lhs; }
#endif
#endif // TRANSPARENT_H