xref: /llvm-project/libcxx/test/std/ranges/range.req/range.range/range_size_t.compile.pass.cpp (revision b8cb1dc9ea87faa8e8e9ab7a31710a8c0bb8b084)
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 // template<sized_range R>
12 // using range_size_t = decltype(ranges::size(declval<R&>()));
13 
14 #include <ranges>
15 #include <concepts>
16 #include <cstddef>
17 
18 #include "test_iterators.h"
19 
20 template<class T>
21 concept has_range_size_t = requires { typename std::ranges::range_size_t<T>; };
22 
23 struct A { int *begin(); int *end(); short size(); };
24 static_assert(std::same_as<std::ranges::range_size_t<A>, short>);
25 static_assert(std::same_as<std::ranges::range_size_t<A&>, short>);
26 static_assert(std::same_as<std::ranges::range_size_t<A&&>, short>);
27 static_assert(!has_range_size_t<const A>);
28 static_assert(!has_range_size_t<const A&>);
29 static_assert(!has_range_size_t<const A&&>);
30 
31 struct B { int *begin(); int *end(); };
32 static_assert(std::same_as<std::ranges::range_size_t<B>, std::size_t>);
33 static_assert(std::same_as<std::ranges::range_size_t<B&>, std::size_t>);
34 static_assert(std::same_as<std::ranges::range_size_t<B&&>, std::size_t>);
35 static_assert(!has_range_size_t<const B>);
36 static_assert(!has_range_size_t<const B&>);
37 static_assert(!has_range_size_t<const B&&>);
38 
39 struct C { bidirectional_iterator<int*> begin(); bidirectional_iterator<int*> end(); };
40 static_assert(!has_range_size_t<C>);
41