llvm/libc/src/__support/CPP/type_traits/add_lvalue_reference.h

//===-- add_lvalue_reference type_traits ------------------------*- C++ -*-===//
//
// 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 LLVM_LIBC_SRC___SUPPORT_CPP_TYPE_TRAITS_ADD_LVALUE_REFERENCE_H
#define LLVM_LIBC_SRC___SUPPORT_CPP_TYPE_TRAITS_ADD_LVALUE_REFERENCE_H

#include "src/__support/CPP/type_traits/type_identity.h"
#include "src/__support/macros/config.h"

namespace LIBC_NAMESPACE_DECL {
namespace cpp {

// add_lvalue_reference
namespace detail {
template <class T> // Note that `cv void&` is a substitution failure
auto try_add_lvalue_reference(int) -> cpp::type_identity<T &>;
template <class T> // Handle T = cv void case
auto try_add_lvalue_reference(...) -> cpp::type_identity<T>;
} // namespace detail
template <class T>
struct add_lvalue_reference : decltype(detail::try_add_lvalue_reference<T>(0)) { … };
add_lvalue_reference_t;

} // namespace cpp
} // namespace LIBC_NAMESPACE_DECL

#endif // LLVM_LIBC_SRC___SUPPORT_CPP_TYPE_TRAITS_ADD_LVALUE_REFERENCE_H