libcxx/test/std/ranges/range.factories/range.iota.view/views_iota.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 // UNSUPPORTED: c++03, c++11, c++14, c++17
  10
  11 // views::iota
  12
  13 #include <cassert>
  14 #include <concepts>
  15 #include <ranges>
  16 #include <type_traits>
  17
  18 #include "test_macros.h"
  19 #include "types.h"
  20
  21 template<class T, class U>
  22 constexpr void testType(U u) {
  23   // Test that this generally does the right thing.
  24   // Test with only one argument.
  25   {
  26     assert(*std::views::iota(T(0)).begin() == T(0));
  27   }
  28   {
  29     const auto io = std::views::iota(T(10));
  30     assert(*io.begin() == T(10));
  31   }
  32   // Test with two arguments.
  33   {
  34     assert(*std::views::iota(T(0), u).begin() == T(0));
  35   }
  36   {
  37     const auto io = std::views::iota(T(10), u);
  38     assert(*io.begin() == T(10));
  39   }
  40   // Test that we return the correct type.
  41   {
  42     ASSERT_SAME_TYPE(decltype(std::views::iota(T(10))), std::ranges::iota_view<T>);
  43     ASSERT_SAME_TYPE(decltype(std::views::iota(T(10), u)), std::ranges::iota_view<T, U>);
  44   }
  45 }
  46
  47 struct X {};
  48
  49 constexpr bool test() {
  50   testType<SomeInt>(SomeInt(10));
  51   testType<SomeInt>(IntComparableWith(SomeInt(10)));
  52   testType<signed long>(IntComparableWith<signed long>(10));
  53   testType<unsigned long>(IntComparableWith<unsigned long>(10));
  54   testType<int>(IntComparableWith<int>(10));
  55   testType<int>(int(10));
  56   testType<unsigned>(unsigned(10));
  57   testType<unsigned>(IntComparableWith<unsigned>(10));
  58   testType<short>(short(10));
  59   testType<short>(IntComparableWith<short>(10));
  60   testType<unsigned short>(IntComparableWith<unsigned short>(10));
  61
  62   {
  63     static_assert( std::is_invocable_v<decltype(std::views::iota), int>);
  64     static_assert(!std::is_invocable_v<decltype(std::views::iota), X>);
  65     static_assert( std::is_invocable_v<decltype(std::views::iota), int, int>);
  66     static_assert(!std::is_invocable_v<decltype(std::views::iota), int, X>);
  67   }
  68   {
  69     static_assert(std::same_as<decltype(std::views::iota), decltype(std::ranges::views::iota)>);
  70   }
  71
  72   return true;
  73 }
  74
  75 int main(int, char**) {
  76   test();
  77   static_assert(test());
  78
  79   return 0;
  80 }