xref: /llvm-project/libcxx/test/std/ranges/range.access/size.pass.cpp (revision 6842f52a0bbf851b43b51fa8dc7dd8dfb533d0e7)
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-no-concepts
11 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
12 
13 // std::ranges::size
14 
15 #include <ranges>
16 
17 #include <cassert>
18 #include "test_macros.h"
19 #include "test_iterators.h"
20 
21 using RangeSizeT = decltype(std::ranges::size);
22 
23 static_assert(!std::is_invocable_v<RangeSizeT, int[]>);
24 static_assert( std::is_invocable_v<RangeSizeT, int[1]>);
25 static_assert( std::is_invocable_v<RangeSizeT, int (&&)[1]>);
26 static_assert( std::is_invocable_v<RangeSizeT, int (&)[1]>);
27 
28 struct Incomplete;
29 static_assert(!std::is_invocable_v<RangeSizeT, Incomplete[]>);
30 static_assert(!std::is_invocable_v<RangeSizeT, Incomplete(&)[]>);
31 static_assert(!std::is_invocable_v<RangeSizeT, Incomplete(&&)[]>);
32 
33 extern Incomplete array_of_incomplete[42];
34 static_assert(std::ranges::size(array_of_incomplete) == 42);
35 static_assert(std::ranges::size(std::move(array_of_incomplete)) == 42);
36 static_assert(std::ranges::size(std::as_const(array_of_incomplete)) == 42);
37 static_assert(std::ranges::size(static_cast<const Incomplete(&&)[42]>(array_of_incomplete)) == 42);
38 
39 static_assert(std::semiregular<std::remove_cv_t<RangeSizeT>>);
40 
41 struct SizeMember {
42   constexpr size_t size() { return 42; }
43 };
44 
45 struct StaticSizeMember {
46   constexpr static size_t size() { return 42; }
47 };
48 
49 static_assert(!std::is_invocable_v<RangeSizeT, const SizeMember>);
50 
51 struct SizeFunction {
52   friend constexpr size_t size(SizeFunction) { return 42; }
53 };
54 
55 // Make sure the size member is preferred.
56 struct SizeMemberAndFunction {
57   constexpr size_t size() { return 42; }
58   friend constexpr size_t size(SizeMemberAndFunction) { return 0; }
59 };
60 
61 bool constexpr testArrayType() {
62   int a[4];
63   int b[1];
64   SizeMember c[4];
65   SizeFunction d[4];
66 
67   assert(std::ranges::size(a) == 4);
68   ASSERT_SAME_TYPE(decltype(std::ranges::size(a)), size_t);
69   assert(std::ranges::size(b) == 1);
70   ASSERT_SAME_TYPE(decltype(std::ranges::size(b)), size_t);
71   assert(std::ranges::size(c) == 4);
72   ASSERT_SAME_TYPE(decltype(std::ranges::size(c)), size_t);
73   assert(std::ranges::size(d) == 4);
74   ASSERT_SAME_TYPE(decltype(std::ranges::size(d)), size_t);
75 
76   return true;
77 }
78 
79 struct SizeMemberConst {
80   constexpr size_t size() const { return 42; }
81 };
82 
83 struct SizeMemberSigned {
84   constexpr long size() { return 42; }
85 };
86 
87 bool constexpr testHasSizeMember() {
88   assert(std::ranges::size(SizeMember()) == 42);
89   ASSERT_SAME_TYPE(decltype(std::ranges::size(SizeMember())), size_t);
90 
91   const SizeMemberConst sizeMemberConst;
92   assert(std::ranges::size(sizeMemberConst) == 42);
93 
94   assert(std::ranges::size(SizeMemberAndFunction()) == 42);
95 
96   assert(std::ranges::size(SizeMemberSigned()) == 42);
97   ASSERT_SAME_TYPE(decltype(std::ranges::size(SizeMemberSigned())), long);
98 
99   assert(std::ranges::size(StaticSizeMember()) == 42);
100   ASSERT_SAME_TYPE(decltype(std::ranges::size(StaticSizeMember())), size_t);
101 
102   return true;
103 }
104 
105 struct MoveOnlySizeFunction {
106   MoveOnlySizeFunction() = default;
107   MoveOnlySizeFunction(MoveOnlySizeFunction &&) = default;
108   MoveOnlySizeFunction(MoveOnlySizeFunction const&) = delete;
109 
110   friend constexpr size_t size(MoveOnlySizeFunction) { return 42; }
111 };
112 
113 enum EnumSizeFunction {
114   a, b
115 };
116 
117 constexpr size_t size(EnumSizeFunction) { return 42; }
118 
119 struct SizeFunctionConst {
120   friend constexpr size_t size(const SizeFunctionConst) { return 42; }
121 };
122 
123 struct SizeFunctionRef {
124   friend constexpr size_t size(SizeFunctionRef&) { return 42; }
125 };
126 
127 struct SizeFunctionConstRef {
128   friend constexpr size_t size(SizeFunctionConstRef const&) { return 42; }
129 };
130 
131 struct SizeFunctionSigned {
132   friend constexpr long size(SizeFunctionSigned) { return 42; }
133 };
134 
135 bool constexpr testHasSizeFunction() {
136   assert(std::ranges::size(SizeFunction()) == 42);
137   ASSERT_SAME_TYPE(decltype(std::ranges::size(SizeFunction())), size_t);
138   static_assert(!std::is_invocable_v<RangeSizeT, MoveOnlySizeFunction>);
139   assert(std::ranges::size(EnumSizeFunction()) == 42);
140   assert(std::ranges::size(SizeFunctionConst()) == 42);
141 
142   SizeFunctionRef a;
143   assert(std::ranges::size(a) == 42);
144 
145   const SizeFunctionConstRef b;
146   assert(std::ranges::size(b) == 42);
147 
148   assert(std::ranges::size(SizeFunctionSigned()) == 42);
149   ASSERT_SAME_TYPE(decltype(std::ranges::size(SizeFunctionSigned())), long);
150 
151   return true;
152 }
153 
154 struct Empty { };
155 static_assert(!std::is_invocable_v<RangeSizeT, Empty>);
156 
157 struct InvalidReturnTypeMember {
158   Empty size();
159 };
160 
161 struct InvalidReturnTypeFunction {
162   friend Empty size(InvalidReturnTypeFunction);
163 };
164 
165 struct Convertible {
166   operator size_t();
167 };
168 
169 struct ConvertibleReturnTypeMember {
170   Convertible size();
171 };
172 
173 struct ConvertibleReturnTypeFunction {
174   friend Convertible size(ConvertibleReturnTypeFunction);
175 };
176 
177 struct BoolReturnTypeMember {
178   bool size() const;
179 };
180 
181 struct BoolReturnTypeFunction {
182   friend bool size(BoolReturnTypeFunction const&);
183 };
184 
185 static_assert(!std::is_invocable_v<RangeSizeT, InvalidReturnTypeMember>);
186 static_assert(!std::is_invocable_v<RangeSizeT, InvalidReturnTypeFunction>);
187 static_assert( std::is_invocable_v<RangeSizeT, InvalidReturnTypeMember (&)[4]>);
188 static_assert( std::is_invocable_v<RangeSizeT, InvalidReturnTypeFunction (&)[4]>);
189 static_assert(!std::is_invocable_v<RangeSizeT, ConvertibleReturnTypeMember>);
190 static_assert(!std::is_invocable_v<RangeSizeT, ConvertibleReturnTypeFunction>);
191 static_assert(!std::is_invocable_v<RangeSizeT, BoolReturnTypeMember const&>);
192 static_assert(!std::is_invocable_v<RangeSizeT, BoolReturnTypeFunction const&>);
193 
194 struct SizeMemberDisabled {
195   size_t size() { return 42; }
196 };
197 
198 template <>
199 inline constexpr bool std::ranges::disable_sized_range<SizeMemberDisabled> = true;
200 
201 struct ImproperlyDisabledMember {
202   size_t size() const { return 42; }
203 };
204 
205 // Intentionally disabling "const ConstSizeMemberDisabled". This doesn't disable anything
206 // because T is always uncvrefed before being checked.
207 template <>
208 inline constexpr bool std::ranges::disable_sized_range<const ImproperlyDisabledMember> = true;
209 
210 struct SizeFunctionDisabled {
211   friend size_t size(SizeFunctionDisabled) { return 42; }
212 };
213 
214 template <>
215 inline constexpr bool std::ranges::disable_sized_range<SizeFunctionDisabled> = true;
216 
217 struct ImproperlyDisabledFunction {
218   friend size_t size(ImproperlyDisabledFunction const&) { return 42; }
219 };
220 
221 template <>
222 inline constexpr bool std::ranges::disable_sized_range<const ImproperlyDisabledFunction> = true;
223 
224 static_assert( std::is_invocable_v<RangeSizeT, ImproperlyDisabledMember&>);
225 static_assert( std::is_invocable_v<RangeSizeT, const ImproperlyDisabledMember&>);
226 static_assert(!std::is_invocable_v<RangeSizeT, ImproperlyDisabledFunction&>);
227 static_assert( std::is_invocable_v<RangeSizeT, const ImproperlyDisabledFunction&>);
228 
229 // No begin end.
230 struct HasMinusOperator {
231   friend constexpr size_t operator-(HasMinusOperator, HasMinusOperator) { return 2; }
232 };
233 static_assert(!std::is_invocable_v<RangeSizeT, HasMinusOperator>);
234 
235 struct HasMinusBeginEnd {
236   struct sentinel {
237     friend bool operator==(sentinel, forward_iterator<int*>);
238     friend constexpr std::ptrdiff_t operator-(const sentinel, const forward_iterator<int*>) { return 2; }
239     friend constexpr std::ptrdiff_t operator-(const forward_iterator<int*>, const sentinel) { return 2; }
240   };
241 
242   friend constexpr forward_iterator<int*> begin(HasMinusBeginEnd) { return {}; }
243   friend constexpr sentinel end(HasMinusBeginEnd) { return {}; }
244 };
245 
246 struct other_forward_iterator : forward_iterator<int*> { };
247 
248 struct InvalidMinusBeginEnd {
249   struct sentinel {
250     friend bool operator==(sentinel, other_forward_iterator);
251     friend constexpr std::ptrdiff_t operator-(const sentinel, const other_forward_iterator) { return 2; }
252     friend constexpr std::ptrdiff_t operator-(const other_forward_iterator, const sentinel) { return 2; }
253   };
254 
255   friend constexpr other_forward_iterator begin(InvalidMinusBeginEnd) { return {}; }
256   friend constexpr sentinel end(InvalidMinusBeginEnd) { return {}; }
257 };
258 
259 // short is integer-like, but it is not other_forward_iterator's difference_type.
260 static_assert(!std::same_as<other_forward_iterator::difference_type, short>);
261 static_assert(!std::is_invocable_v<RangeSizeT, InvalidMinusBeginEnd>);
262 
263 struct RandomAccessRange {
264   struct sentinel {
265     friend bool operator==(sentinel, random_access_iterator<int*>);
266     friend constexpr std::ptrdiff_t operator-(const sentinel, const random_access_iterator<int*>) { return 2; }
267     friend constexpr std::ptrdiff_t operator-(const random_access_iterator<int*>, const sentinel) { return 2; }
268   };
269 
270   constexpr random_access_iterator<int*> begin() { return {}; }
271   constexpr sentinel end() { return {}; }
272 };
273 
274 struct IntPtrBeginAndEnd {
275   int buff[8];
276   constexpr int* begin() { return buff; }
277   constexpr int* end() { return buff + 8; }
278 };
279 
280 struct DisabledSizeRangeWithBeginEnd {
281   int buff[8];
282   constexpr int* begin() { return buff; }
283   constexpr int* end() { return buff + 8; }
284   constexpr size_t size() { return 1; }
285 };
286 
287 template <>
288 inline constexpr bool std::ranges::disable_sized_range<DisabledSizeRangeWithBeginEnd> = true;
289 
290 struct SizeBeginAndEndMembers {
291   int buff[8];
292   constexpr int* begin() { return buff; }
293   constexpr int* end() { return buff + 8; }
294   constexpr size_t size() { return 1; }
295 };
296 
297 constexpr bool testRanges() {
298   HasMinusBeginEnd a;
299   assert(std::ranges::size(a) == 2);
300   // Ensure that this is converted to an *unsigned* type.
301   ASSERT_SAME_TYPE(decltype(std::ranges::size(a)), size_t);
302 
303   IntPtrBeginAndEnd b;
304   assert(std::ranges::size(b) == 8);
305 
306   DisabledSizeRangeWithBeginEnd c;
307   assert(std::ranges::size(c) == 8);
308 
309   RandomAccessRange d;
310   assert(std::ranges::size(d) == 2);
311   ASSERT_SAME_TYPE(decltype(std::ranges::size(d)), size_t);
312 
313   SizeBeginAndEndMembers e;
314   assert(std::ranges::size(e) == 1);
315 
316   return true;
317 }
318 
319 int main(int, char**) {
320   testArrayType();
321   static_assert(testArrayType());
322 
323   testHasSizeMember();
324   static_assert(testHasSizeMember());
325 
326   testHasSizeFunction();
327   static_assert(testHasSizeFunction());
328 
329   testRanges();
330   static_assert(testRanges());
331 
332   return 0;
333 }
334