1 //===----------------------------------------------------------------------===// 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 #ifndef TEST_SUPPORT_COUNTING_PROJECTION_H 10 #define TEST_SUPPORT_COUNTING_PROJECTION_H 11 12 #include <functional> 13 #include <utility> 14 #include "test_macros.h" 15 16 #if TEST_STD_VER > 14 17 18 template <class Proj = std::identity> 19 class counting_projection { 20 Proj proj_; 21 int* count_ = nullptr; 22 23 public: 24 constexpr counting_projection() = default; counting_projection(int & count)25 constexpr counting_projection(int& count) : count_(&count) {} counting_projection(Proj proj,int & count)26 constexpr counting_projection(Proj proj, int& count) : proj_(std::move(proj)), count_(&count) {} 27 28 template <class T> decltype(auto)29 constexpr decltype(auto) operator()(T&& value) const { 30 ++(*count_); 31 return std::invoke(proj_, std::forward<T>(value)); 32 } 33 }; 34 35 counting_projection(int& count) -> counting_projection<std::identity>; 36 template <class Proj> 37 counting_projection(Proj proj, int& count) -> counting_projection<Proj>; 38 39 #endif // TEST_STD_VER > 14 40 41 #endif // TEST_SUPPORT_COUNTING_PROJECTION_H 42