libcxx/test/std/containers/from_range_helpers.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 SUPPORT_FROM_RANGE_HELPERS_H
  10 #define SUPPORT_FROM_RANGE_HELPERS_H
  11
  12 #include <array>
  13 #include <cstddef>
  14 #include <iterator>
  15 #include <type_traits>
  16 #include <vector>
  17
  18 #include "min_allocator.h"
  19 #include "test_allocator.h"
  20 #include "test_iterators.h"
  21 #include "test_macros.h"
  22 #include "type_algorithms.h"
  23
  24 struct Empty {};
  25
  26 template <class T>
  27 struct InputRange {
  28   cpp20_input_iterator<T*> begin();
  29   sentinel_wrapper<cpp20_input_iterator<T*>> end();
  30 };
  31
  32 template <class Iter, class Sent, std::ranges::input_range Range>
  33 constexpr auto wrap_input(Range&& input) {
  34   auto b = Iter(std::ranges::begin(input));
  35   auto e = Sent(Iter(std::ranges::end(input)));
  36   return std::ranges::subrange(std::move(b), std::move(e));
  37 }
  38
  39 template <class Iter, class Sent, class T, std::size_t N>
  40 constexpr auto wrap_input(std::array<T, N>& input) {
  41   auto b = Iter(input.data());
  42   auto e = Sent(Iter(input.data() + input.size()));
  43   return std::ranges::subrange(std::move(b), std::move(e));
  44 }
  45
  46 template <class Iter, class Sent, class T>
  47 constexpr auto wrap_input(std::vector<T>& input) {
  48   auto b = Iter(input.data());
  49   auto e = Sent(Iter(input.data() + input.size()));
  50   return std::ranges::subrange(std::move(b), std::move(e));
  51 }
  52
  53 struct KeyValue {
  54   int key; // Only the key is considered for equality comparison.
  55   char value; // Allows distinguishing equivalent instances.
  56
  57   bool operator<(const KeyValue& other) const { return key < other.key; }
  58   bool operator==(const KeyValue& other) const { return key == other.key; }
  59 };
  60
  61 template <>
  62 struct std::hash<KeyValue> {
  63   std::size_t operator()(const KeyValue& kv) const {
  64     return kv.key;
  65   }
  66 };
  67
  68 #if !defined(TEST_HAS_NO_EXCEPTIONS)
  69
  70 template <class T>
  71 struct ThrowingAllocator {
  72   using value_type = T;
  73   using char_type = T;
  74   using is_always_equal = std::false_type;
  75
  76   ThrowingAllocator() = default;
  77
  78   template <class U>
  79   ThrowingAllocator(const ThrowingAllocator<U>&) {}
  80
  81   T* allocate(std::size_t) { throw 1; }
  82   void deallocate(T*, std::size_t) {}
  83
  84   template <class U>
  85   friend bool operator==(const ThrowingAllocator&, const ThrowingAllocator<U>&) {
  86     return true;
  87   }
  88 };
  89 #endif
  90
  91 template <class T, class Func>
  92 constexpr void for_all_iterators_and_allocators(Func f) {
  93   using Iterators = types::type_list<
  94     cpp20_input_iterator<T*>,
  95     forward_iterator<T*>,
  96     bidirectional_iterator<T*>,
  97     random_access_iterator<T*>,
  98     contiguous_iterator<T*>,
  99     T*
 100   >;
 101
 102   types::for_each(Iterators{}, [=]<class Iter>() {
 103     f.template operator()<Iter, sentinel_wrapper<Iter>, std::allocator<T>>();
 104     f.template operator()<Iter, sentinel_wrapper<Iter>, test_allocator<T>>();
 105     f.template operator()<Iter, sentinel_wrapper<Iter>, min_allocator<T>>();
 106     f.template operator()<Iter, sentinel_wrapper<Iter>, safe_allocator<T>>();
 107
 108     if constexpr (std::sentinel_for<Iter, Iter>) {
 109       f.template operator()<Iter, Iter, std::allocator<T>>();
 110       f.template operator()<Iter, Iter, test_allocator<T>>();
 111       f.template operator()<Iter, Iter, min_allocator<T>>();
 112       f.template operator()<Iter, Iter, safe_allocator<T>>();
 113     }
 114   });
 115 }
 116
 117 #endif // SUPPORT_FROM_RANGE_HELPERS_H