Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 14 | pmbaty | 1 | //===- llvm/ADT/STLFunctionalExtras.h - Extras for <functional> -*- 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 contains some extension to <functional>. |
||
| 10 | // |
||
| 11 | // No library is required when using these functions. |
||
| 12 | // |
||
| 13 | //===----------------------------------------------------------------------===// |
||
| 14 | |||
| 15 | #ifndef LLVM_ADT_STLFUNCTIONALEXTRAS_H |
||
| 16 | #define LLVM_ADT_STLFUNCTIONALEXTRAS_H |
||
| 17 | |||
| 18 | #include "llvm/ADT/STLForwardCompat.h" |
||
| 19 | |||
| 20 | #include <type_traits> |
||
| 21 | #include <utility> |
||
| 22 | #include <cstdint> |
||
| 23 | |||
| 24 | namespace llvm { |
||
| 25 | |||
| 26 | //===----------------------------------------------------------------------===// |
||
| 27 | // Extra additions to <functional> |
||
| 28 | //===----------------------------------------------------------------------===// |
||
| 29 | |||
| 30 | /// An efficient, type-erasing, non-owning reference to a callable. This is |
||
| 31 | /// intended for use as the type of a function parameter that is not used |
||
| 32 | /// after the function in question returns. |
||
| 33 | /// |
||
| 34 | /// This class does not own the callable, so it is not in general safe to store |
||
| 35 | /// a function_ref. |
||
| 36 | template<typename Fn> class function_ref; |
||
| 37 | |||
| 38 | template<typename Ret, typename ...Params> |
||
| 39 | class function_ref<Ret(Params...)> { |
||
| 40 | Ret (*callback)(intptr_t callable, Params ...params) = nullptr; |
||
| 41 | intptr_t callable; |
||
| 42 | |||
| 43 | template<typename Callable> |
||
| 44 | static Ret callback_fn(intptr_t callable, Params ...params) { |
||
| 45 | return (*reinterpret_cast<Callable*>(callable))( |
||
| 46 | std::forward<Params>(params)...); |
||
| 47 | } |
||
| 48 | |||
| 49 | public: |
||
| 50 | function_ref() = default; |
||
| 51 | function_ref(std::nullptr_t) {} |
||
| 52 | |||
| 53 | template <typename Callable> |
||
| 54 | function_ref( |
||
| 55 | Callable &&callable, |
||
| 56 | // This is not the copy-constructor. |
||
| 57 | std::enable_if_t<!std::is_same<remove_cvref_t<Callable>, |
||
| 58 | function_ref>::value> * = nullptr, |
||
| 59 | // Functor must be callable and return a suitable type. |
||
| 60 | std::enable_if_t<std::is_void<Ret>::value || |
||
| 61 | std::is_convertible<decltype(std::declval<Callable>()( |
||
| 62 | std::declval<Params>()...)), |
||
| 63 | Ret>::value> * = nullptr) |
||
| 64 | : callback(callback_fn<std::remove_reference_t<Callable>>), |
||
| 65 | callable(reinterpret_cast<intptr_t>(&callable)) {} |
||
| 66 | |||
| 67 | Ret operator()(Params ...params) const { |
||
| 68 | return callback(callable, std::forward<Params>(params)...); |
||
| 69 | } |
||
| 70 | |||
| 71 | explicit operator bool() const { return callback; } |
||
| 72 | }; |
||
| 73 | |||
| 74 | } // end namespace llvm |
||
| 75 | |||
| 76 | #endif // LLVM_ADT_STLFUNCTIONALEXTRAS_H |