libcxx/test/std/iterators/iterator.primitives/iterator.basic/iterator.pass.cpp

   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 // <iterator>
  10
  11 // template<class Category, class T, class Distance = ptrdiff_t,
  12 //          class Pointer = T*, class Reference = T&>
  13 // struct iterator
  14 // {
  15 //   typedef T         value_type;
  16 //   typedef Distance  difference_type;
  17 //   typedef Pointer   pointer;
  18 //   typedef Reference reference;
  19 //   typedef Category  iterator_category;
  20 // };
  21
  22 #include <iterator>
  23 #include <type_traits>
  24
  25 #include "test_macros.h"
  26
  27 struct A {};
  28
  29 template <class T>
  30 void
  31 test2()
  32 {
  33     typedef std::iterator<std::forward_iterator_tag, T> It;
  34     static_assert((std::is_same<typename It::value_type, T>::value), "");
  35     static_assert((std::is_same<typename It::difference_type, std::ptrdiff_t>::value), "");
  36     static_assert((std::is_same<typename It::pointer, T*>::value), "");
  37     static_assert((std::is_same<typename It::reference, T&>::value), "");
  38     static_assert((std::is_same<typename It::iterator_category, std::forward_iterator_tag>::value), "");
  39 }
  40
  41 template <class T>
  42 void
  43 test3()
  44 {
  45     typedef std::iterator<std::bidirectional_iterator_tag, T, short> It;
  46     static_assert((std::is_same<typename It::value_type, T>::value), "");
  47     static_assert((std::is_same<typename It::difference_type, short>::value), "");
  48     static_assert((std::is_same<typename It::pointer, T*>::value), "");
  49     static_assert((std::is_same<typename It::reference, T&>::value), "");
  50     static_assert((std::is_same<typename It::iterator_category, std::bidirectional_iterator_tag>::value), "");
  51 }
  52
  53 template <class T>
  54 void
  55 test4()
  56 {
  57     typedef std::iterator<std::random_access_iterator_tag, T, int, const T*> It;
  58     static_assert((std::is_same<typename It::value_type, T>::value), "");
  59     static_assert((std::is_same<typename It::difference_type, int>::value), "");
  60     static_assert((std::is_same<typename It::pointer, const T*>::value), "");
  61     static_assert((std::is_same<typename It::reference, T&>::value), "");
  62     static_assert((std::is_same<typename It::iterator_category, std::random_access_iterator_tag>::value), "");
  63 }
  64
  65 template <class T>
  66 void
  67 test5()
  68 {
  69     typedef std::iterator<std::input_iterator_tag, T, long, const T*, const T&> It;
  70     static_assert((std::is_same<typename It::value_type, T>::value), "");
  71     static_assert((std::is_same<typename It::difference_type, long>::value), "");
  72     static_assert((std::is_same<typename It::pointer, const T*>::value), "");
  73     static_assert((std::is_same<typename It::reference, const T&>::value), "");
  74     static_assert((std::is_same<typename It::iterator_category, std::input_iterator_tag>::value), "");
  75 }
  76
  77 int main(int, char**)
  78 {
  79     test2<A>();
  80     test3<A>();
  81     test4<A>();
  82     test5<A>();
  83
  84   return 0;
  85 }