xref: /llvm-project/libcxx/test/std/ranges/range.access/ssize.pass.cpp (revision d2baefae6846765eef6a6dd69d4fdf1082ce29ad)
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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
11 
12 // std::ranges::ssize
13 
14 #include <ranges>
15 
16 #include <cassert>
17 #include "test_macros.h"
18 #include "test_iterators.h"
19 
20 using RangeSSizeT = decltype(std::ranges::ssize);
21 
22 static_assert(!std::is_invocable_v<RangeSSizeT, int[]>);
23 static_assert( std::is_invocable_v<RangeSSizeT, int[1]>);
24 static_assert( std::is_invocable_v<RangeSSizeT, int (&&)[1]>);
25 static_assert( std::is_invocable_v<RangeSSizeT, int (&)[1]>);
26 
27 struct SizeMember {
28   constexpr size_t size() { return 42; }
29 };
30 static_assert(!std::is_invocable_v<decltype(std::ranges::ssize), const SizeMember&>);
31 
32 struct SizeFunction {
33   friend constexpr size_t size(SizeFunction) { return 42; }
34 };
35 
36 struct SizeFunctionSigned {
37   friend constexpr std::ptrdiff_t size(SizeFunctionSigned) { return 42; }
38 };
39 
40 struct SizedSentinelRange {
41   int data_[2] = {};
42   constexpr int *begin() { return data_; }
43   constexpr auto end() { return sized_sentinel<int*>(data_ + 2); }
44 };
45 
46 struct ShortUnsignedReturnType {
47   constexpr unsigned short size() { return 42; }
48 };
49 
50 // size_t changes depending on the platform.
51 using SignedSizeT = std::make_signed_t<size_t>;
52 
53 constexpr bool test() {
54   int a[4];
55 
56   assert(std::ranges::ssize(a) == 4);
57   ASSERT_SAME_TYPE(decltype(std::ranges::ssize(a)), SignedSizeT);
58 
59   assert(std::ranges::ssize(SizeMember()) == 42);
60   ASSERT_SAME_TYPE(decltype(std::ranges::ssize(SizeMember())), SignedSizeT);
61 
62   assert(std::ranges::ssize(SizeFunction()) == 42);
63   ASSERT_SAME_TYPE(decltype(std::ranges::ssize(SizeFunction())), SignedSizeT);
64 
65   assert(std::ranges::ssize(SizeFunctionSigned()) == 42);
66   ASSERT_SAME_TYPE(decltype(std::ranges::ssize(SizeFunctionSigned())), std::ptrdiff_t);
67 
68   SizedSentinelRange b;
69   assert(std::ranges::ssize(b) == 2);
70   ASSERT_SAME_TYPE(decltype(std::ranges::ssize(b)), std::ptrdiff_t);
71 
72   // This gets converted to ptrdiff_t because it's wider.
73   ShortUnsignedReturnType c;
74   assert(std::ranges::ssize(c) == 42);
75   ASSERT_SAME_TYPE(decltype(std::ranges::ssize(c)), ptrdiff_t);
76 
77   return true;
78 }
79 
80 // Test ADL-proofing.
81 struct Incomplete;
82 template<class T> struct Holder { T t; };
83 static_assert(!std::is_invocable_v<RangeSSizeT, Holder<Incomplete>*>);
84 static_assert(!std::is_invocable_v<RangeSSizeT, Holder<Incomplete>*&>);
85 
86 int main(int, char**) {
87   test();
88   static_assert(test());
89 
90   return 0;
91 }
92