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1 | # =========================================================================== |
2 | # https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html | |
3 | # =========================================================================== | |
4 | # | |
5 | # SYNOPSIS | |
6 | # | |
7 | # AX_CXX_COMPILE_STDCXX(VERSION, [ext|noext], [mandatory|optional]) | |
8 | # | |
9 | # DESCRIPTION | |
10 | # | |
11 | # Check for baseline language coverage in the compiler for the specified | |
12 | # version of the C++ standard. If necessary, add switches to CXX and | |
13 | # CXXCPP to enable support. VERSION may be '11' (for the C++11 standard) | |
14 | # or '14' (for the C++14 standard). | |
15 | # | |
16 | # The second argument, if specified, indicates whether you insist on an | |
17 | # extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g. | |
18 | # -std=c++11). If neither is specified, you get whatever works, with | |
19 | # preference for an extended mode. | |
20 | # | |
21 | # The third argument, if specified 'mandatory' or if left unspecified, | |
22 | # indicates that baseline support for the specified C++ standard is | |
23 | # required and that the macro should error out if no mode with that | |
24 | # support is found. If specified 'optional', then configuration proceeds | |
25 | # regardless, after defining HAVE_CXX${VERSION} if and only if a | |
26 | # supporting mode is found. | |
27 | # | |
28 | # LICENSE | |
29 | # | |
30 | # Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com> | |
31 | # Copyright (c) 2012 Zack Weinberg <zackw@panix.com> | |
32 | # Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu> | |
33 | # Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com> | |
34 | # Copyright (c) 2015 Paul Norman <penorman@mac.com> | |
35 | # Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu> | |
36 | # Copyright (c) 2016 Krzesimir Nowak <qdlacz@gmail.com> | |
37 | # | |
38 | # Copying and distribution of this file, with or without modification, are | |
39 | # permitted in any medium without royalty provided the copyright notice | |
40 | # and this notice are preserved. This file is offered as-is, without any | |
41 | # warranty. | |
42 | ||
43 | #serial 7 | |
44 | ||
45 | dnl This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro | |
46 | dnl (serial version number 13). | |
47 | ||
48 | AX_REQUIRE_DEFINED([AC_MSG_WARN]) | |
49 | AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl | |
50 | m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"], | |
51 | [$1], [14], [ax_cxx_compile_alternatives="14 1y"], | |
52 | [$1], [17], [ax_cxx_compile_alternatives="17 1z"], | |
53 | [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl | |
54 | m4_if([$2], [], [], | |
55 | [$2], [ext], [], | |
56 | [$2], [noext], [], | |
57 | [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX])])dnl | |
58 | m4_if([$3], [], [ax_cxx_compile_cxx$1_required=true], | |
59 | [$3], [mandatory], [ax_cxx_compile_cxx$1_required=true], | |
60 | [$3], [optional], [ax_cxx_compile_cxx$1_required=false], | |
61 | [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])]) | |
62 | AC_LANG_PUSH([C++])dnl | |
63 | ac_success=no | |
64 | AC_CACHE_CHECK(whether $CXX supports C++$1 features by default, | |
65 | ax_cv_cxx_compile_cxx$1, | |
66 | [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], | |
67 | [ax_cv_cxx_compile_cxx$1=yes], | |
68 | [ax_cv_cxx_compile_cxx$1=no])]) | |
69 | if test x$ax_cv_cxx_compile_cxx$1 = xyes; then | |
70 | ac_success=yes | |
71 | fi | |
72 | ||
73 | m4_if([$2], [noext], [], [dnl | |
74 | if test x$ac_success = xno; then | |
75 | for alternative in ${ax_cxx_compile_alternatives}; do | |
76 | switch="-std=gnu++${alternative}" | |
77 | cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) | |
78 | AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, | |
79 | $cachevar, | |
80 | [ac_save_CXX="$CXX" | |
81 | CXX="$CXX $switch" | |
82 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], | |
83 | [eval $cachevar=yes], | |
84 | [eval $cachevar=no]) | |
85 | CXX="$ac_save_CXX"]) | |
86 | if eval test x\$$cachevar = xyes; then | |
87 | CXX="$CXX $switch" | |
88 | if test -n "$CXXCPP" ; then | |
89 | CXXCPP="$CXXCPP $switch" | |
90 | fi | |
91 | ac_success=yes | |
92 | break | |
93 | fi | |
94 | done | |
95 | fi]) | |
96 | ||
97 | m4_if([$2], [ext], [], [dnl | |
98 | if test x$ac_success = xno; then | |
99 | dnl HP's aCC needs +std=c++11 according to: | |
100 | dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf | |
101 | dnl Cray's crayCC needs "-h std=c++11" | |
102 | for alternative in ${ax_cxx_compile_alternatives}; do | |
103 | for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do | |
104 | cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) | |
105 | AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, | |
106 | $cachevar, | |
107 | [ac_save_CXX="$CXX" | |
108 | CXX="$CXX $switch" | |
109 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], | |
110 | [eval $cachevar=yes], | |
111 | [eval $cachevar=no]) | |
112 | CXX="$ac_save_CXX"]) | |
113 | if eval test x\$$cachevar = xyes; then | |
114 | CXX="$CXX $switch" | |
115 | if test -n "$CXXCPP" ; then | |
116 | CXXCPP="$CXXCPP $switch" | |
117 | fi | |
118 | ac_success=yes | |
119 | break | |
120 | fi | |
121 | done | |
122 | if test x$ac_success = xyes; then | |
123 | break | |
124 | fi | |
125 | done | |
126 | fi]) | |
127 | AC_LANG_POP([C++]) | |
128 | if test x$ax_cxx_compile_cxx$1_required = xtrue; then | |
129 | if test x$ac_success = xno; then | |
130 | AC_MSG_ERROR([*** A compiler with support for C++$1 language features is required.]) | |
131 | fi | |
132 | fi | |
133 | if test x$ac_success = xno; then | |
134 | HAVE_CXX$1=0 | |
135 | AC_MSG_NOTICE([No compiler with C++$1 support was found]) | |
136 | else | |
137 | HAVE_CXX$1=1 | |
138 | AC_DEFINE(HAVE_CXX$1,1, | |
139 | [define if the compiler supports basic C++$1 syntax]) | |
140 | fi | |
141 | AC_SUBST(HAVE_CXX$1) | |
142 | m4_if([$1], [17], [AC_MSG_WARN([C++17 is not yet standardized, so the checks may change in incompatible ways anytime])]) | |
143 | ]) | |
144 | ||
145 | ||
146 | dnl Test body for checking C++11 support | |
147 | ||
148 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11], | |
149 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 | |
150 | ) | |
151 | ||
152 | ||
153 | dnl Test body for checking C++14 support | |
154 | ||
155 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14], | |
156 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 | |
157 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 | |
158 | ) | |
159 | ||
160 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17], | |
161 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 | |
162 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 | |
163 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_17 | |
164 | ) | |
165 | ||
166 | dnl Tests for new features in C++11 | |
167 | ||
168 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[ | |
169 | ||
170 | // If the compiler admits that it is not ready for C++11, why torture it? | |
171 | // Hopefully, this will speed up the test. | |
172 | ||
173 | #ifndef __cplusplus | |
174 | ||
175 | #error "This is not a C++ compiler" | |
176 | ||
177 | #elif __cplusplus < 201103L | |
178 | ||
179 | #error "This is not a C++11 compiler" | |
180 | ||
181 | #else | |
182 | ||
183 | namespace cxx11 | |
184 | { | |
185 | ||
186 | namespace test_static_assert | |
187 | { | |
188 | ||
189 | template <typename T> | |
190 | struct check | |
191 | { | |
192 | static_assert(sizeof(int) <= sizeof(T), "not big enough"); | |
193 | }; | |
194 | ||
195 | } | |
196 | ||
197 | namespace test_final_override | |
198 | { | |
199 | ||
200 | struct Base | |
201 | { | |
202 | virtual void f() {} | |
203 | }; | |
204 | ||
205 | struct Derived : public Base | |
206 | { | |
207 | virtual void f() override {} | |
208 | }; | |
209 | ||
210 | } | |
211 | ||
212 | namespace test_double_right_angle_brackets | |
213 | { | |
214 | ||
215 | template < typename T > | |
216 | struct check {}; | |
217 | ||
218 | typedef check<void> single_type; | |
219 | typedef check<check<void>> double_type; | |
220 | typedef check<check<check<void>>> triple_type; | |
221 | typedef check<check<check<check<void>>>> quadruple_type; | |
222 | ||
223 | } | |
224 | ||
225 | namespace test_decltype | |
226 | { | |
227 | ||
228 | int | |
229 | f() | |
230 | { | |
231 | int a = 1; | |
232 | decltype(a) b = 2; | |
233 | return a + b; | |
234 | } | |
235 | ||
236 | } | |
237 | ||
238 | namespace test_type_deduction | |
239 | { | |
240 | ||
241 | template < typename T1, typename T2 > | |
242 | struct is_same | |
243 | { | |
244 | static const bool value = false; | |
245 | }; | |
246 | ||
247 | template < typename T > | |
248 | struct is_same<T, T> | |
249 | { | |
250 | static const bool value = true; | |
251 | }; | |
252 | ||
253 | template < typename T1, typename T2 > | |
254 | auto | |
255 | add(T1 a1, T2 a2) -> decltype(a1 + a2) | |
256 | { | |
257 | return a1 + a2; | |
258 | } | |
259 | ||
260 | int | |
261 | test(const int c, volatile int v) | |
262 | { | |
263 | static_assert(is_same<int, decltype(0)>::value == true, ""); | |
264 | static_assert(is_same<int, decltype(c)>::value == false, ""); | |
265 | static_assert(is_same<int, decltype(v)>::value == false, ""); | |
266 | auto ac = c; | |
267 | auto av = v; | |
268 | auto sumi = ac + av + 'x'; | |
269 | auto sumf = ac + av + 1.0; | |
270 | static_assert(is_same<int, decltype(ac)>::value == true, ""); | |
271 | static_assert(is_same<int, decltype(av)>::value == true, ""); | |
272 | static_assert(is_same<int, decltype(sumi)>::value == true, ""); | |
273 | static_assert(is_same<int, decltype(sumf)>::value == false, ""); | |
274 | static_assert(is_same<int, decltype(add(c, v))>::value == true, ""); | |
275 | return (sumf > 0.0) ? sumi : add(c, v); | |
276 | } | |
277 | ||
278 | } | |
279 | ||
280 | namespace test_noexcept | |
281 | { | |
282 | ||
283 | int f() { return 0; } | |
284 | int g() noexcept { return 0; } | |
285 | ||
286 | static_assert(noexcept(f()) == false, ""); | |
287 | static_assert(noexcept(g()) == true, ""); | |
288 | ||
289 | } | |
290 | ||
291 | namespace test_constexpr | |
292 | { | |
293 | ||
294 | template < typename CharT > | |
295 | unsigned long constexpr | |
296 | strlen_c_r(const CharT *const s, const unsigned long acc) noexcept | |
297 | { | |
298 | return *s ? strlen_c_r(s + 1, acc + 1) : acc; | |
299 | } | |
300 | ||
301 | template < typename CharT > | |
302 | unsigned long constexpr | |
303 | strlen_c(const CharT *const s) noexcept | |
304 | { | |
305 | return strlen_c_r(s, 0UL); | |
306 | } | |
307 | ||
308 | static_assert(strlen_c("") == 0UL, ""); | |
309 | static_assert(strlen_c("1") == 1UL, ""); | |
310 | static_assert(strlen_c("example") == 7UL, ""); | |
311 | static_assert(strlen_c("another\0example") == 7UL, ""); | |
312 | ||
313 | } | |
314 | ||
315 | namespace test_rvalue_references | |
316 | { | |
317 | ||
318 | template < int N > | |
319 | struct answer | |
320 | { | |
321 | static constexpr int value = N; | |
322 | }; | |
323 | ||
324 | answer<1> f(int&) { return answer<1>(); } | |
325 | answer<2> f(const int&) { return answer<2>(); } | |
326 | answer<3> f(int&&) { return answer<3>(); } | |
327 | ||
328 | void | |
329 | test() | |
330 | { | |
331 | int i = 0; | |
332 | const int c = 0; | |
333 | static_assert(decltype(f(i))::value == 1, ""); | |
334 | static_assert(decltype(f(c))::value == 2, ""); | |
335 | static_assert(decltype(f(0))::value == 3, ""); | |
336 | } | |
337 | ||
338 | } | |
339 | ||
340 | namespace test_uniform_initialization | |
341 | { | |
342 | ||
343 | struct test | |
344 | { | |
345 | static const int zero {}; | |
346 | static const int one {1}; | |
347 | }; | |
348 | ||
349 | static_assert(test::zero == 0, ""); | |
350 | static_assert(test::one == 1, ""); | |
351 | ||
352 | } | |
353 | ||
354 | namespace test_lambdas | |
355 | { | |
356 | ||
357 | void | |
358 | test1() | |
359 | { | |
360 | auto lambda1 = [](){}; | |
361 | auto lambda2 = lambda1; | |
362 | lambda1(); | |
363 | lambda2(); | |
364 | } | |
365 | ||
366 | int | |
367 | test2() | |
368 | { | |
369 | auto a = [](int i, int j){ return i + j; }(1, 2); | |
370 | auto b = []() -> int { return '0'; }(); | |
371 | auto c = [=](){ return a + b; }(); | |
372 | auto d = [&](){ return c; }(); | |
373 | auto e = [a, &b](int x) mutable { | |
374 | const auto identity = [](int y){ return y; }; | |
375 | for (auto i = 0; i < a; ++i) | |
376 | a += b--; | |
377 | return x + identity(a + b); | |
378 | }(0); | |
379 | return a + b + c + d + e; | |
380 | } | |
381 | ||
382 | int | |
383 | test3() | |
384 | { | |
385 | const auto nullary = [](){ return 0; }; | |
386 | const auto unary = [](int x){ return x; }; | |
387 | using nullary_t = decltype(nullary); | |
388 | using unary_t = decltype(unary); | |
389 | const auto higher1st = [](nullary_t f){ return f(); }; | |
390 | const auto higher2nd = [unary](nullary_t f1){ | |
391 | return [unary, f1](unary_t f2){ return f2(unary(f1())); }; | |
392 | }; | |
393 | return higher1st(nullary) + higher2nd(nullary)(unary); | |
394 | } | |
395 | ||
396 | } | |
397 | ||
398 | namespace test_variadic_templates | |
399 | { | |
400 | ||
401 | template <int...> | |
402 | struct sum; | |
403 | ||
404 | template <int N0, int... N1toN> | |
405 | struct sum<N0, N1toN...> | |
406 | { | |
407 | static constexpr auto value = N0 + sum<N1toN...>::value; | |
408 | }; | |
409 | ||
410 | template <> | |
411 | struct sum<> | |
412 | { | |
413 | static constexpr auto value = 0; | |
414 | }; | |
415 | ||
416 | static_assert(sum<>::value == 0, ""); | |
417 | static_assert(sum<1>::value == 1, ""); | |
418 | static_assert(sum<23>::value == 23, ""); | |
419 | static_assert(sum<1, 2>::value == 3, ""); | |
420 | static_assert(sum<5, 5, 11>::value == 21, ""); | |
421 | static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); | |
422 | ||
423 | } | |
424 | ||
425 | // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae | |
426 | // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function | |
427 | // because of this. | |
428 | namespace test_template_alias_sfinae | |
429 | { | |
430 | ||
431 | struct foo {}; | |
432 | ||
433 | template<typename T> | |
434 | using member = typename T::member_type; | |
435 | ||
436 | template<typename T> | |
437 | void func(...) {} | |
438 | ||
439 | template<typename T> | |
440 | void func(member<T>*) {} | |
441 | ||
442 | void test(); | |
443 | ||
444 | void test() { func<foo>(0); } | |
445 | ||
446 | } | |
447 | ||
448 | } // namespace cxx11 | |
449 | ||
450 | #endif // __cplusplus >= 201103L | |
451 | ||
452 | ]]) | |
453 | ||
454 | ||
455 | dnl Tests for new features in C++14 | |
456 | ||
457 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[ | |
458 | ||
459 | // If the compiler admits that it is not ready for C++14, why torture it? | |
460 | // Hopefully, this will speed up the test. | |
461 | ||
462 | #ifndef __cplusplus | |
463 | ||
464 | #error "This is not a C++ compiler" | |
465 | ||
466 | #elif __cplusplus < 201402L | |
467 | ||
468 | #error "This is not a C++14 compiler" | |
469 | ||
470 | #else | |
471 | ||
472 | namespace cxx14 | |
473 | { | |
474 | ||
475 | namespace test_polymorphic_lambdas | |
476 | { | |
477 | ||
478 | int | |
479 | test() | |
480 | { | |
481 | const auto lambda = [](auto&&... args){ | |
482 | const auto istiny = [](auto x){ | |
483 | return (sizeof(x) == 1UL) ? 1 : 0; | |
484 | }; | |
485 | const int aretiny[] = { istiny(args)... }; | |
486 | return aretiny[0]; | |
487 | }; | |
488 | return lambda(1, 1L, 1.0f, '1'); | |
489 | } | |
490 | ||
491 | } | |
492 | ||
493 | namespace test_binary_literals | |
494 | { | |
495 | ||
496 | constexpr auto ivii = 0b0000000000101010; | |
497 | static_assert(ivii == 42, "wrong value"); | |
498 | ||
499 | } | |
500 | ||
501 | namespace test_generalized_constexpr | |
502 | { | |
503 | ||
504 | template < typename CharT > | |
505 | constexpr unsigned long | |
506 | strlen_c(const CharT *const s) noexcept | |
507 | { | |
508 | auto length = 0UL; | |
509 | for (auto p = s; *p; ++p) | |
510 | ++length; | |
511 | return length; | |
512 | } | |
513 | ||
514 | static_assert(strlen_c("") == 0UL, ""); | |
515 | static_assert(strlen_c("x") == 1UL, ""); | |
516 | static_assert(strlen_c("test") == 4UL, ""); | |
517 | static_assert(strlen_c("another\0test") == 7UL, ""); | |
518 | ||
519 | } | |
520 | ||
521 | namespace test_lambda_init_capture | |
522 | { | |
523 | ||
524 | int | |
525 | test() | |
526 | { | |
527 | auto x = 0; | |
528 | const auto lambda1 = [a = x](int b){ return a + b; }; | |
529 | const auto lambda2 = [a = lambda1(x)](){ return a; }; | |
530 | return lambda2(); | |
531 | } | |
532 | ||
533 | } | |
534 | ||
535 | namespace test_digit_separators | |
536 | { | |
537 | ||
538 | constexpr auto ten_million = 100'000'000; | |
539 | static_assert(ten_million == 100000000, ""); | |
540 | ||
541 | } | |
542 | ||
543 | namespace test_return_type_deduction | |
544 | { | |
545 | ||
546 | auto f(int& x) { return x; } | |
547 | decltype(auto) g(int& x) { return x; } | |
548 | ||
549 | template < typename T1, typename T2 > | |
550 | struct is_same | |
551 | { | |
552 | static constexpr auto value = false; | |
553 | }; | |
554 | ||
555 | template < typename T > | |
556 | struct is_same<T, T> | |
557 | { | |
558 | static constexpr auto value = true; | |
559 | }; | |
560 | ||
561 | int | |
562 | test() | |
563 | { | |
564 | auto x = 0; | |
565 | static_assert(is_same<int, decltype(f(x))>::value, ""); | |
566 | static_assert(is_same<int&, decltype(g(x))>::value, ""); | |
567 | return x; | |
568 | } | |
569 | ||
570 | } | |
571 | ||
572 | } // namespace cxx14 | |
573 | ||
574 | #endif // __cplusplus >= 201402L | |
575 | ||
576 | ]]) | |
577 | ||
578 | ||
579 | dnl Tests for new features in C++17 | |
580 | ||
581 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[ | |
582 | ||
583 | // If the compiler admits that it is not ready for C++17, why torture it? | |
584 | // Hopefully, this will speed up the test. | |
585 | ||
586 | #ifndef __cplusplus | |
587 | ||
588 | #error "This is not a C++ compiler" | |
589 | ||
590 | #elif __cplusplus <= 201402L | |
591 | ||
592 | #error "This is not a C++17 compiler" | |
593 | ||
594 | #else | |
595 | ||
596 | #if defined(__clang__) | |
597 | #define REALLY_CLANG | |
598 | #else | |
599 | #if defined(__GNUC__) | |
600 | #define REALLY_GCC | |
601 | #endif | |
602 | #endif | |
603 | ||
604 | #include <initializer_list> | |
605 | #include <utility> | |
606 | #include <type_traits> | |
607 | ||
608 | namespace cxx17 | |
609 | { | |
610 | ||
611 | #if !defined(REALLY_CLANG) | |
612 | namespace test_constexpr_lambdas | |
613 | { | |
614 | ||
615 | // TODO: test it with clang++ from git | |
616 | ||
617 | constexpr int foo = [](){return 42;}(); | |
618 | ||
619 | } | |
620 | #endif // !defined(REALLY_CLANG) | |
621 | ||
622 | namespace test::nested_namespace::definitions | |
623 | { | |
624 | ||
625 | } | |
626 | ||
627 | namespace test_fold_expression | |
628 | { | |
629 | ||
630 | template<typename... Args> | |
631 | int multiply(Args... args) | |
632 | { | |
633 | return (args * ... * 1); | |
634 | } | |
635 | ||
636 | template<typename... Args> | |
637 | bool all(Args... args) | |
638 | { | |
639 | return (args && ...); | |
640 | } | |
641 | ||
642 | } | |
643 | ||
644 | namespace test_extended_static_assert | |
645 | { | |
646 | ||
647 | static_assert (true); | |
648 | ||
649 | } | |
650 | ||
651 | namespace test_auto_brace_init_list | |
652 | { | |
653 | ||
654 | auto foo = {5}; | |
655 | auto bar {5}; | |
656 | ||
657 | static_assert(std::is_same<std::initializer_list<int>, decltype(foo)>::value); | |
658 | static_assert(std::is_same<int, decltype(bar)>::value); | |
659 | } | |
660 | ||
661 | namespace test_typename_in_template_template_parameter | |
662 | { | |
663 | ||
664 | template<template<typename> typename X> struct D; | |
665 | ||
666 | } | |
667 | ||
668 | namespace test_fallthrough_nodiscard_maybe_unused_attributes | |
669 | { | |
670 | ||
671 | int f1() | |
672 | { | |
673 | return 42; | |
674 | } | |
675 | ||
676 | [[nodiscard]] int f2() | |
677 | { | |
678 | [[maybe_unused]] auto unused = f1(); | |
679 | ||
680 | switch (f1()) | |
681 | { | |
682 | case 17: | |
683 | f1(); | |
684 | [[fallthrough]]; | |
685 | case 42: | |
686 | f1(); | |
687 | } | |
688 | return f1(); | |
689 | } | |
690 | ||
691 | } | |
692 | ||
693 | namespace test_extended_aggregate_initialization | |
694 | { | |
695 | ||
696 | struct base1 | |
697 | { | |
698 | int b1, b2 = 42; | |
699 | }; | |
700 | ||
701 | struct base2 | |
702 | { | |
703 | base2() { | |
704 | b3 = 42; | |
705 | } | |
706 | int b3; | |
707 | }; | |
708 | ||
709 | struct derived : base1, base2 | |
710 | { | |
711 | int d; | |
712 | }; | |
713 | ||
714 | derived d1 {{1, 2}, {}, 4}; // full initialization | |
715 | derived d2 {{}, {}, 4}; // value-initialized bases | |
716 | ||
717 | } | |
718 | ||
719 | namespace test_general_range_based_for_loop | |
720 | { | |
721 | ||
722 | struct iter | |
723 | { | |
724 | int i; | |
725 | ||
726 | int& operator* () | |
727 | { | |
728 | return i; | |
729 | } | |
730 | ||
731 | const int& operator* () const | |
732 | { | |
733 | return i; | |
734 | } | |
735 | ||
736 | iter& operator++() | |
737 | { | |
738 | ++i; | |
739 | return *this; | |
740 | } | |
741 | }; | |
742 | ||
743 | struct sentinel | |
744 | { | |
745 | int i; | |
746 | }; | |
747 | ||
748 | bool operator== (const iter& i, const sentinel& s) | |
749 | { | |
750 | return i.i == s.i; | |
751 | } | |
752 | ||
753 | bool operator!= (const iter& i, const sentinel& s) | |
754 | { | |
755 | return !(i == s); | |
756 | } | |
757 | ||
758 | struct range | |
759 | { | |
760 | iter begin() const | |
761 | { | |
762 | return {0}; | |
763 | } | |
764 | ||
765 | sentinel end() const | |
766 | { | |
767 | return {5}; | |
768 | } | |
769 | }; | |
770 | ||
771 | void f() | |
772 | { | |
773 | range r {}; | |
774 | ||
775 | for (auto i : r) | |
776 | { | |
777 | [[maybe_unused]] auto v = i; | |
778 | } | |
779 | } | |
780 | ||
781 | } | |
782 | ||
783 | namespace test_lambda_capture_asterisk_this_by_value | |
784 | { | |
785 | ||
786 | struct t | |
787 | { | |
788 | int i; | |
789 | int foo() | |
790 | { | |
791 | return [*this]() | |
792 | { | |
793 | return i; | |
794 | }(); | |
795 | } | |
796 | }; | |
797 | ||
798 | } | |
799 | ||
800 | namespace test_enum_class_construction | |
801 | { | |
802 | ||
803 | enum class byte : unsigned char | |
804 | {}; | |
805 | ||
806 | byte foo {42}; | |
807 | ||
808 | } | |
809 | ||
810 | namespace test_constexpr_if | |
811 | { | |
812 | ||
813 | template <bool cond> | |
814 | int f () | |
815 | { | |
816 | if constexpr(cond) | |
817 | { | |
818 | return 13; | |
819 | } | |
820 | else | |
821 | { | |
822 | return 42; | |
823 | } | |
824 | } | |
825 | ||
826 | } | |
827 | ||
828 | namespace test_selection_statement_with_initializer | |
829 | { | |
830 | ||
831 | int f() | |
832 | { | |
833 | return 13; | |
834 | } | |
835 | ||
836 | int f2() | |
837 | { | |
838 | if (auto i = f(); i > 0) | |
839 | { | |
840 | return 3; | |
841 | } | |
842 | ||
843 | switch (auto i = f(); i + 4) | |
844 | { | |
845 | case 17: | |
846 | return 2; | |
847 | ||
848 | default: | |
849 | return 1; | |
850 | } | |
851 | } | |
852 | ||
853 | } | |
854 | ||
855 | #if !defined(REALLY_CLANG) | |
856 | namespace test_template_argument_deduction_for_class_templates | |
857 | { | |
858 | ||
859 | // TODO: test it with clang++ from git | |
860 | ||
861 | template <typename T1, typename T2> | |
862 | struct pair | |
863 | { | |
864 | pair (T1 p1, T2 p2) | |
865 | : m1 {p1}, | |
866 | m2 {p2} | |
867 | {} | |
868 | ||
869 | T1 m1; | |
870 | T2 m2; | |
871 | }; | |
872 | ||
873 | void f() | |
874 | { | |
875 | [[maybe_unused]] auto p = pair{13, 42u}; | |
876 | } | |
877 | ||
878 | } | |
879 | #endif // !defined(REALLY_CLANG) | |
880 | ||
881 | namespace test_non_type_auto_template_parameters | |
882 | { | |
883 | ||
884 | template <auto n> | |
885 | struct B | |
886 | {}; | |
887 | ||
888 | B<5> b1; | |
889 | B<'a'> b2; | |
890 | ||
891 | } | |
892 | ||
893 | #if !defined(REALLY_CLANG) | |
894 | namespace test_structured_bindings | |
895 | { | |
896 | ||
897 | // TODO: test it with clang++ from git | |
898 | ||
899 | int arr[2] = { 1, 2 }; | |
900 | std::pair<int, int> pr = { 1, 2 }; | |
901 | ||
902 | auto f1() -> int(&)[2] | |
903 | { | |
904 | return arr; | |
905 | } | |
906 | ||
907 | auto f2() -> std::pair<int, int>& | |
908 | { | |
909 | return pr; | |
910 | } | |
911 | ||
912 | struct S | |
913 | { | |
914 | int x1 : 2; | |
915 | volatile double y1; | |
916 | }; | |
917 | ||
918 | S f3() | |
919 | { | |
920 | return {}; | |
921 | } | |
922 | ||
923 | auto [ x1, y1 ] = f1(); | |
924 | auto& [ xr1, yr1 ] = f1(); | |
925 | auto [ x2, y2 ] = f2(); | |
926 | auto& [ xr2, yr2 ] = f2(); | |
927 | const auto [ x3, y3 ] = f3(); | |
928 | ||
929 | } | |
930 | #endif // !defined(REALLY_CLANG) | |
931 | ||
932 | #if !defined(REALLY_CLANG) | |
933 | namespace test_exception_spec_type_system | |
934 | { | |
935 | ||
936 | // TODO: test it with clang++ from git | |
937 | ||
938 | struct Good {}; | |
939 | struct Bad {}; | |
940 | ||
941 | void g1() noexcept; | |
942 | void g2(); | |
943 | ||
944 | template<typename T> | |
945 | Bad | |
946 | f(T*, T*); | |
947 | ||
948 | template<typename T1, typename T2> | |
949 | Good | |
950 | f(T1*, T2*); | |
951 | ||
952 | static_assert (std::is_same_v<Good, decltype(f(g1, g2))>); | |
953 | ||
954 | } | |
955 | #endif // !defined(REALLY_CLANG) | |
956 | ||
957 | namespace test_inline_variables | |
958 | { | |
959 | ||
960 | template<class T> void f(T) | |
961 | {} | |
962 | ||
963 | template<class T> inline T g(T) | |
964 | { | |
965 | return T{}; | |
966 | } | |
967 | ||
968 | template<> inline void f<>(int) | |
969 | {} | |
970 | ||
971 | template<> int g<>(int) | |
972 | { | |
973 | return 5; | |
974 | } | |
975 | ||
976 | } | |
977 | ||
978 | } // namespace cxx17 | |
979 | ||
980 | #endif // __cplusplus <= 201402L | |
981 | ||
982 | ]]) |