1 //===-- forward utility -----------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 #ifndef LLVM_LIBC_SRC___SUPPORT_CPP_UTILITY_FORWARD_H 9 #define LLVM_LIBC_SRC___SUPPORT_CPP_UTILITY_FORWARD_H 10 11 #include "src/__support/CPP/type_traits/is_lvalue_reference.h" 12 #include "src/__support/CPP/type_traits/remove_reference.h" 13 #include "src/__support/macros/attributes.h" 14 #include "src/__support/macros/config.h" 15 16 namespace LIBC_NAMESPACE_DECL { 17 namespace cpp { 18 19 // forward 20 template <typename T> forward(remove_reference_t<T> & value)21LIBC_INLINE constexpr T &&forward(remove_reference_t<T> &value) { 22 return static_cast<T &&>(value); 23 } 24 25 template <typename T> forward(remove_reference_t<T> && value)26LIBC_INLINE constexpr T &&forward(remove_reference_t<T> &&value) { 27 static_assert(!is_lvalue_reference_v<T>, 28 "cannot forward an rvalue as an lvalue"); 29 return static_cast<T &&>(value); 30 } 31 32 } // namespace cpp 33 } // namespace LIBC_NAMESPACE_DECL 34 35 #endif // LLVM_LIBC_SRC___SUPPORT_CPP_UTILITY_FORWARD_H 36