| 1 | //===- llvm/ADT/Identity.h - Provide std::identity from C++20 ---*- 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 | // |
|---|
| 9 | // This file provides an implementation of std::identity from C++20. |
|---|
| 10 | // |
|---|
| 11 | // No library is required when using these functions. |
|---|
| 12 | // |
|---|
| 13 | //===----------------------------------------------------------------------===// |
|---|
| 14 | |
|---|
| 15 | #ifndef LLVM_ADT_IDENTITY_H |
|---|
| 16 | #define LLVM_ADT_IDENTITY_H |
|---|
| 17 | |
|---|
| 18 | |
|---|
| 19 | namespace llvm { |
|---|
| 20 | |
|---|
| 21 | // Similar to `std::identity` from C++20. |
|---|
| 22 | template <class Ty> struct identity { |
|---|
| 23 | using is_transparent = void; |
|---|
| 24 | using argument_type = Ty; |
|---|
| 25 | |
|---|
| 26 | Ty &operator()(Ty &self) const { |
|---|
| 27 | return self; |
|---|
| 28 | } |
|---|
| 29 | const Ty &operator()(const Ty &self) const { |
|---|
| 30 | return self; |
|---|
| 31 | } |
|---|
| 32 | }; |
|---|
| 33 | |
|---|
| 34 | } // end namespace llvm |
|---|
| 35 | |
|---|
| 36 | #endif // LLVM_ADT_IDENTITY_H |
|---|
| 37 | |
|---|
