libcxx/test/support/counting_predicates.h

   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_PREDICATES_H
  10 #define TEST_SUPPORT_COUNTING_PREDICATES_H
  11
  12 #include <cstddef>
  13 #include <utility>
  14 #include "test_macros.h"
  15
  16 template <typename Predicate, typename Arg>
  17 struct unary_counting_predicate {
  18 public:
  19     typedef Arg argument_type;
  20     typedef bool result_type;
  21
  22     unary_counting_predicate(Predicate p) : p_(p), count_(0) {}
  23     unary_counting_predicate(const unary_counting_predicate&) = default;
  24     unary_counting_predicate& operator=(const unary_counting_predicate&) = default;
  25     ~unary_counting_predicate() {}
  26
  27     bool operator () (const Arg &a) const { ++count_; return p_(a); }
  28     std::size_t count() const { return count_; }
  29     void reset() { count_ = 0; }
  30
  31 private:
  32     Predicate p_;
  33     mutable std::size_t count_;
  34 };
  35
  36
  37 template <typename Predicate, typename Arg1, typename Arg2=Arg1>
  38 struct binary_counting_predicate {
  39 public:
  40     typedef Arg1 first_argument_type;
  41     typedef Arg2 second_argument_type;
  42     typedef bool result_type;
  43
  44     binary_counting_predicate ( Predicate p ) : p_(p), count_(0) {}
  45     ~binary_counting_predicate() {}
  46
  47     bool operator () (const Arg1 &a1, const Arg2 &a2) const { ++count_; return p_(a1, a2); }
  48     std::size_t count() const { return count_; }
  49     void reset() { count_ = 0; }
  50
  51 private:
  52     Predicate p_;
  53     mutable std::size_t count_;
  54 };
  55
  56 #if TEST_STD_VER > 14
  57
  58 template <class Predicate>
  59 class counting_predicate {
  60   Predicate pred_;
  61   int* count_ = nullptr;
  62
  63 public:
  64   constexpr counting_predicate() = default;
  65   constexpr counting_predicate(Predicate pred, int& count) : pred_(std::move(pred)), count_(&count) {}
  66
  67   template <class... Args>
  68   constexpr decltype(auto) operator()(Args&& ...args) {
  69     ++(*count_);
  70     return pred_(std::forward<Args>(args)...);
  71   }
  72
  73   template <class... Args>
  74   constexpr decltype(auto) operator()(Args&& ...args) const {
  75     ++(*count_);
  76     return pred_(std::forward<Args>(args)...);
  77   }
  78 };
  79
  80 template <class Predicate>
  81 counting_predicate(Predicate pred, int& count) -> counting_predicate<Predicate>;
  82
  83 #endif // TEST_STD_VER > 14
  84
  85 #endif // TEST_SUPPORT_COUNTING_PREDICATES_H