libcxx/test/support/boolean_testable.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 LIBCXX_TEST_SUPPORT_BOOLEAN_TESTABLE_H
  10 #define LIBCXX_TEST_SUPPORT_BOOLEAN_TESTABLE_H
  11
  12 #include "test_macros.h"
  13
  14 #if TEST_STD_VER > 17
  15
  16 class BooleanTestable {
  17 public:
  18   constexpr operator bool() const {
  19     return value_;
  20   }
  21
  22   friend constexpr BooleanTestable operator==(const BooleanTestable& lhs, const BooleanTestable& rhs) {
  23     return lhs.value_ == rhs.value_;
  24   }
  25
  26   friend constexpr BooleanTestable operator!=(const BooleanTestable& lhs, const BooleanTestable& rhs) {
  27     return !(lhs == rhs);
  28   }
  29
  30   constexpr BooleanTestable operator!() {
  31     return BooleanTestable{!value_};
  32   }
  33
  34   // this class should behave like a bool, so the constructor shouldn't be explicit
  35   constexpr BooleanTestable(bool value) : value_{value} {}
  36   constexpr BooleanTestable(const BooleanTestable&) = delete;
  37   constexpr BooleanTestable(BooleanTestable&&) = delete;
  38
  39 private:
  40   bool value_;
  41 };
  42
  43 template <class T>
  44 class StrictComparable {
  45 public:
  46   // this shouldn't be explicit to make it easier to initlaize inside arrays (which it almost always is)
  47   constexpr StrictComparable(T value) : value_{value} {}
  48
  49   friend constexpr BooleanTestable operator==(const StrictComparable& lhs, const StrictComparable& rhs) {
  50     return (lhs.value_ == rhs.value_);
  51   }
  52
  53   friend constexpr BooleanTestable operator!=(const StrictComparable& lhs, const StrictComparable& rhs) {
  54     return !(lhs == rhs);
  55   }
  56
  57 private:
  58   T value_;
  59 };
  60
  61 #endif // TEST_STD_VER > 17
  62
  63 #endif // LIBCXX_TEST_SUPPORT_BOOLEAN_TESTABLE_H