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6b513475 | 1 | // Primitive numeric conversions (to_chars and from_chars) -*- C++ -*- |
2 | ||
fbd26352 | 3 | // Copyright (C) 2017-2019 Free Software Foundation, Inc. |
6b513475 | 4 | // |
5 | // This file is part of the GNU ISO C++ Library. This library is free | |
6 | // software; you can redistribute it and/or modify it under the | |
7 | // terms of the GNU General Public License as published by the | |
8 | // Free Software Foundation; either version 3, or (at your option) | |
9 | // any later version. | |
10 | ||
11 | // This library is distributed in the hope that it will be useful, | |
12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | // GNU General Public License for more details. | |
15 | ||
16 | // Under Section 7 of GPL version 3, you are granted additional | |
17 | // permissions described in the GCC Runtime Library Exception, version | |
18 | // 3.1, as published by the Free Software Foundation. | |
19 | ||
20 | // You should have received a copy of the GNU General Public License and | |
21 | // a copy of the GCC Runtime Library Exception along with this program; | |
22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
23 | // <http://www.gnu.org/licenses/>. | |
24 | ||
25 | /** @file include/charconv | |
26 | * This is a Standard C++ Library header. | |
27 | */ | |
28 | ||
29 | #ifndef _GLIBCXX_CHARCONV | |
30 | #define _GLIBCXX_CHARCONV 1 | |
31 | ||
32 | #pragma GCC system_header | |
33 | ||
34 | #if __cplusplus >= 201402L | |
35 | ||
36 | #include <type_traits> | |
37 | #include <limits> | |
38 | #include <cctype> | |
39 | #include <bits/error_constants.h> // for std::errc | |
40 | ||
41 | namespace std _GLIBCXX_VISIBILITY(default) | |
42 | { | |
43 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
44 | ||
45 | /// Result type of std::to_chars | |
46 | struct to_chars_result | |
47 | { | |
48 | char* ptr; | |
49 | errc ec; | |
50 | }; | |
51 | ||
52 | /// Result type of std::from_chars | |
53 | struct from_chars_result | |
54 | { | |
55 | const char* ptr; | |
56 | errc ec; | |
57 | }; | |
58 | ||
59 | namespace __detail | |
60 | { | |
61 | template<typename _Tp, typename... _Types> | |
62 | using __is_one_of = __or_<is_same<_Tp, _Types>...>; | |
63 | ||
64 | template<typename _Tp> | |
65 | using __is_int_to_chars_type = __and_<is_integral<_Tp>, | |
66 | __not_<__is_one_of<_Tp, bool, char16_t, char32_t | |
67 | #if _GLIBCXX_USE_WCHAR_T | |
68 | , wchar_t | |
25694c85 | 69 | #endif |
70 | #if _GLIBCXX_USE_CHAR8_T | |
71 | , char8_t | |
6b513475 | 72 | #endif |
73 | >>>; | |
74 | ||
75 | template<typename _Tp> | |
76 | using __integer_to_chars_result_type | |
77 | = enable_if_t<__is_int_to_chars_type<_Tp>::value, to_chars_result>; | |
78 | ||
79 | template<typename _Tp> | |
80 | using __unsigned_least_t | |
81 | = conditional_t<(sizeof(_Tp) <= sizeof(int)), unsigned int, | |
82 | conditional_t<(sizeof(_Tp) <= sizeof(long)), unsigned long, | |
83 | conditional_t<(sizeof(_Tp) <= sizeof(long long)), unsigned long long, | |
84 | #if _GLIBCXX_USE_INT128 | |
85 | conditional_t<(sizeof(_Tp) <= sizeof(__int128)), unsigned __int128, | |
86 | #endif | |
50521ed1 | 87 | void |
88 | #if _GLIBCXX_USE_INT128 | |
89 | > | |
90 | #endif | |
91 | >>>; | |
6b513475 | 92 | |
93 | // Generic implementation for arbitrary bases. | |
94 | template<typename _Tp> | |
95 | constexpr unsigned | |
96 | __to_chars_len(_Tp __value, int __base = 10) noexcept | |
97 | { | |
98 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
99 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
100 | ||
101 | unsigned __n = 1; | |
102 | const int __b2 = __base * __base; | |
103 | const int __b3 = __b2 * __base; | |
104 | const int __b4 = __b3 * __base; | |
105 | for (;;) | |
106 | { | |
107 | if (__value < __base) return __n; | |
108 | if (__value < __b2) return __n + 1; | |
109 | if (__value < __b3) return __n + 2; | |
110 | if (__value < __b4) return __n + 3; | |
111 | __value /= (unsigned)__b4; | |
112 | __n += 4; | |
113 | } | |
114 | } | |
115 | ||
116 | template<typename _Tp> | |
117 | constexpr unsigned | |
118 | __to_chars_len_2(_Tp __value) noexcept | |
119 | { | |
120 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
121 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
122 | ||
123 | constexpr size_t __nbits = __CHAR_BIT__ * sizeof(_Tp); | |
124 | ||
125 | // N.B. __builtin_clzll is undefined if __value == 0, but std::to_chars | |
126 | // handles zero values directly. | |
127 | ||
128 | // For sizeof(_Tp) > 1 this is an order of magnitude faster than | |
129 | // the generic __to_chars_len. | |
130 | return __nbits | |
131 | - (__builtin_clzll(__value) | |
132 | - ((__CHAR_BIT__ * sizeof(long long)) - __nbits)); | |
133 | } | |
134 | ||
135 | template<typename _Tp> | |
136 | constexpr unsigned | |
137 | __to_chars_len_8(_Tp __value) noexcept | |
138 | { | |
139 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
140 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
141 | ||
142 | constexpr size_t __nbits = __CHAR_BIT__ * sizeof(_Tp); | |
143 | ||
144 | if _GLIBCXX17_CONSTEXPR (__nbits <= 16) | |
145 | { | |
146 | return __value > 077777u ? 6u | |
147 | : __value > 07777u ? 5u | |
148 | : __value > 0777u ? 4u | |
149 | : __value > 077u ? 3u | |
150 | : __value > 07u ? 2u | |
151 | : 1u; | |
152 | } | |
153 | else | |
154 | return __to_chars_len(__value, 8); | |
155 | } | |
156 | ||
157 | // Generic implementation for arbitrary bases. | |
158 | template<typename _Tp> | |
159 | to_chars_result | |
160 | __to_chars(char* __first, char* __last, _Tp __val, int __base) noexcept | |
161 | { | |
162 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
163 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
164 | ||
165 | to_chars_result __res; | |
166 | ||
167 | const unsigned __len = __to_chars_len(__val, __base); | |
168 | ||
169 | if (__builtin_expect((__last - __first) < __len, 0)) | |
170 | { | |
171 | __res.ptr = __last; | |
172 | __res.ec = errc::value_too_large; | |
173 | return __res; | |
174 | } | |
175 | ||
176 | unsigned __pos = __len - 1; | |
177 | ||
178 | static constexpr char __digits[] | |
179 | = "0123456789abcdefghijklmnopqrstuvwxyz"; | |
180 | ||
181 | while (__val >= __base) | |
182 | { | |
183 | auto const __quo = __val / __base; | |
184 | auto const __rem = __val % __base; | |
185 | __first[__pos--] = __digits[__rem]; | |
186 | __val = __quo; | |
187 | } | |
188 | *__first = __digits[__val]; | |
189 | ||
190 | __res.ptr = __first + __len; | |
191 | __res.ec = {}; | |
192 | return __res; | |
193 | } | |
194 | ||
195 | template<typename _Tp> | |
196 | __integer_to_chars_result_type<_Tp> | |
197 | __to_chars_16(char* __first, char* __last, _Tp __val) noexcept | |
198 | { | |
199 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
200 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
201 | ||
202 | to_chars_result __res; | |
203 | ||
204 | const unsigned __len = __to_chars_len(__val, 0x10); | |
205 | ||
206 | if (__builtin_expect((__last - __first) < __len, 0)) | |
207 | { | |
208 | __res.ptr = __last; | |
209 | __res.ec = errc::value_too_large; | |
210 | return __res; | |
211 | } | |
212 | ||
213 | static constexpr char __digits[513] = | |
214 | "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f" | |
215 | "202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f" | |
216 | "404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f" | |
217 | "606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f" | |
218 | "808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f" | |
219 | "a0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebf" | |
220 | "c0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedf" | |
221 | "e0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff"; | |
222 | unsigned __pos = __len - 1; | |
223 | while (__val >= 0x100) | |
224 | { | |
225 | auto const __num = (__val % 0x100) * 2; | |
226 | __val /= 0x100; | |
227 | __first[__pos] = __digits[__num + 1]; | |
228 | __first[__pos - 1] = __digits[__num]; | |
229 | __pos -= 2; | |
230 | } | |
231 | if (__val >= 0x10) | |
232 | { | |
233 | auto const __num = __val * 2; | |
234 | __first[__pos] = __digits[__num + 1]; | |
235 | __first[__pos - 1] = __digits[__num]; | |
236 | } | |
237 | else | |
238 | __first[__pos] = "0123456789abcdef"[__val]; | |
239 | __res.ptr = __first + __len; | |
240 | __res.ec = {}; | |
241 | return __res; | |
242 | } | |
243 | ||
244 | template<typename _Tp> | |
245 | __integer_to_chars_result_type<_Tp> | |
246 | __to_chars_10(char* __first, char* __last, _Tp __val) noexcept | |
247 | { | |
248 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
249 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
250 | ||
251 | to_chars_result __res; | |
252 | ||
253 | const unsigned __len = __to_chars_len(__val, 10); | |
254 | ||
255 | if (__builtin_expect((__last - __first) < __len, 0)) | |
256 | { | |
257 | __res.ptr = __last; | |
258 | __res.ec = errc::value_too_large; | |
259 | return __res; | |
260 | } | |
261 | ||
262 | static constexpr char __digits[201] = | |
263 | "0001020304050607080910111213141516171819" | |
264 | "2021222324252627282930313233343536373839" | |
265 | "4041424344454647484950515253545556575859" | |
266 | "6061626364656667686970717273747576777879" | |
267 | "8081828384858687888990919293949596979899"; | |
268 | unsigned __pos = __len - 1; | |
269 | while (__val >= 100) | |
270 | { | |
271 | auto const __num = (__val % 100) * 2; | |
272 | __val /= 100; | |
273 | __first[__pos] = __digits[__num + 1]; | |
274 | __first[__pos - 1] = __digits[__num]; | |
275 | __pos -= 2; | |
276 | } | |
277 | if (__val >= 10) | |
278 | { | |
279 | auto const __num = __val * 2; | |
280 | __first[__pos] = __digits[__num + 1]; | |
281 | __first[__pos - 1] = __digits[__num]; | |
282 | } | |
283 | else | |
284 | __first[__pos] = '0' + __val; | |
285 | __res.ptr = __first + __len; | |
286 | __res.ec = {}; | |
287 | return __res; | |
288 | } | |
289 | ||
290 | template<typename _Tp> | |
291 | __integer_to_chars_result_type<_Tp> | |
292 | __to_chars_8(char* __first, char* __last, _Tp __val) noexcept | |
293 | { | |
294 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
295 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
296 | ||
297 | to_chars_result __res; | |
298 | ||
299 | const unsigned __len = __to_chars_len_8(__val); | |
300 | ||
301 | if (__builtin_expect((__last - __first) < __len, 0)) | |
302 | { | |
303 | __res.ptr = __last; | |
304 | __res.ec = errc::value_too_large; | |
305 | return __res; | |
306 | } | |
307 | ||
308 | static constexpr char __digits[129] = | |
309 | "00010203040506071011121314151617" | |
310 | "20212223242526273031323334353637" | |
311 | "40414243444546475051525354555657" | |
312 | "60616263646566677071727374757677"; | |
313 | unsigned __pos = __len - 1; | |
314 | while (__val >= 0100) | |
315 | { | |
316 | auto const __num = (__val % 0100) * 2; | |
317 | __val /= 0100; | |
318 | __first[__pos] = __digits[__num + 1]; | |
319 | __first[__pos - 1] = __digits[__num]; | |
320 | __pos -= 2; | |
321 | } | |
322 | if (__val >= 010) | |
323 | { | |
324 | auto const __num = __val * 2; | |
325 | __first[__pos] = __digits[__num + 1]; | |
326 | __first[__pos - 1] = __digits[__num]; | |
327 | } | |
328 | else | |
329 | __first[__pos] = '0' + __val; | |
330 | __res.ptr = __first + __len; | |
331 | __res.ec = {}; | |
332 | return __res; | |
333 | } | |
334 | ||
335 | template<typename _Tp> | |
336 | __integer_to_chars_result_type<_Tp> | |
337 | __to_chars_2(char* __first, char* __last, _Tp __val) noexcept | |
338 | { | |
339 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
340 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
341 | ||
342 | to_chars_result __res; | |
343 | ||
344 | const unsigned __len = __to_chars_len_2(__val); | |
345 | ||
346 | if (__builtin_expect((__last - __first) < __len, 0)) | |
347 | { | |
348 | __res.ptr = __last; | |
349 | __res.ec = errc::value_too_large; | |
350 | return __res; | |
351 | } | |
352 | ||
353 | unsigned __pos = __len - 1; | |
354 | ||
355 | while (__pos) | |
356 | { | |
357 | __first[__pos--] = '0' + (__val & 1); | |
358 | __val >>= 1; | |
359 | } | |
360 | *__first = '0' + (__val & 1); | |
361 | ||
362 | __res.ptr = __first + __len; | |
363 | __res.ec = {}; | |
364 | return __res; | |
365 | } | |
366 | ||
367 | } // namespace __detail | |
368 | ||
369 | template<typename _Tp> | |
370 | __detail::__integer_to_chars_result_type<_Tp> | |
371 | to_chars(char* __first, char* __last, _Tp __value, int __base = 10) | |
372 | { | |
373 | __glibcxx_assert(2 <= __base && __base <= 36); | |
374 | ||
375 | using _Up = __detail::__unsigned_least_t<_Tp>; | |
376 | _Up __unsigned_val = __value; | |
377 | ||
378 | if (__value == 0 && __first != __last) | |
379 | { | |
380 | *__first = '0'; | |
381 | return { __first + 1, errc{} }; | |
382 | } | |
383 | ||
384 | if _GLIBCXX17_CONSTEXPR (std::is_signed<_Tp>::value) | |
385 | if (__value < 0) | |
386 | { | |
387 | if (__builtin_expect(__first != __last, 1)) | |
388 | *__first++ = '-'; | |
389 | __unsigned_val = _Up(~__value) + _Up(1); | |
390 | } | |
391 | ||
392 | switch (__base) | |
393 | { | |
394 | case 16: | |
395 | return __detail::__to_chars_16(__first, __last, __unsigned_val); | |
396 | case 10: | |
397 | return __detail::__to_chars_10(__first, __last, __unsigned_val); | |
398 | case 8: | |
399 | return __detail::__to_chars_8(__first, __last, __unsigned_val); | |
400 | case 2: | |
401 | return __detail::__to_chars_2(__first, __last, __unsigned_val); | |
402 | default: | |
403 | return __detail::__to_chars(__first, __last, __unsigned_val, __base); | |
404 | } | |
405 | } | |
406 | ||
407 | namespace __detail | |
408 | { | |
409 | template<typename _Tp> | |
410 | bool | |
411 | __raise_and_add(_Tp& __val, int __base, unsigned char __c) | |
412 | { | |
413 | if (__builtin_mul_overflow(__val, __base, &__val) | |
414 | || __builtin_add_overflow(__val, __c, &__val)) | |
415 | return false; | |
416 | return true; | |
417 | } | |
418 | ||
419 | /// std::from_chars implementation for integers in base 2. | |
420 | template<typename _Tp> | |
421 | bool | |
422 | __from_chars_binary(const char*& __first, const char* __last, _Tp& __val) | |
423 | { | |
424 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
425 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
426 | ||
427 | const ptrdiff_t __len = __last - __first; | |
428 | int __i = 0; | |
429 | while (__i < __len) | |
430 | { | |
431 | const unsigned char __c = (unsigned)__first[__i] - '0'; | |
432 | if (__c < 2) | |
433 | __val = (__val << 1) | __c; | |
434 | else | |
435 | break; | |
436 | __i++; | |
437 | } | |
438 | __first += __i; | |
439 | return __i <= (sizeof(_Tp) * __CHAR_BIT__); | |
440 | } | |
441 | ||
442 | /// std::from_chars implementation for integers in bases 3 to 10. | |
443 | template<typename _Tp> | |
444 | bool | |
445 | __from_chars_digit(const char*& __first, const char* __last, _Tp& __val, | |
446 | int __base) | |
447 | { | |
448 | static_assert(is_integral<_Tp>::value, "implementation bug"); | |
449 | static_assert(is_unsigned<_Tp>::value, "implementation bug"); | |
450 | ||
451 | auto __matches = [__base](char __c) { | |
452 | return '0' <= __c && __c <= ('0' + (__base - 1)); | |
453 | }; | |
454 | ||
455 | while (__first != __last) | |
456 | { | |
457 | const char __c = *__first; | |
458 | if (__matches(__c)) | |
459 | { | |
460 | if (!__raise_and_add(__val, __base, __c - '0')) | |
461 | { | |
462 | while (++__first != __last && __matches(*__first)) | |
463 | ; | |
464 | return false; | |
465 | } | |
466 | __first++; | |
467 | } | |
468 | else | |
469 | return true; | |
470 | } | |
471 | return true; | |
472 | } | |
473 | ||
474 | constexpr unsigned char | |
475 | __from_chars_alpha_to_num(char __c) | |
476 | { | |
477 | switch (__c) | |
478 | { | |
479 | case 'a': | |
480 | case 'A': | |
481 | return 10; | |
482 | case 'b': | |
483 | case 'B': | |
484 | return 11; | |
485 | case 'c': | |
486 | case 'C': | |
487 | return 12; | |
488 | case 'd': | |
489 | case 'D': | |
490 | return 13; | |
491 | case 'e': | |
492 | case 'E': | |
493 | return 14; | |
494 | case 'f': | |
495 | case 'F': | |
496 | return 15; | |
497 | case 'g': | |
498 | case 'G': | |
499 | return 16; | |
500 | case 'h': | |
501 | case 'H': | |
502 | return 17; | |
503 | case 'i': | |
504 | case 'I': | |
505 | return 18; | |
506 | case 'j': | |
507 | case 'J': | |
508 | return 19; | |
509 | case 'k': | |
510 | case 'K': | |
511 | return 20; | |
512 | case 'l': | |
513 | case 'L': | |
514 | return 21; | |
515 | case 'm': | |
516 | case 'M': | |
517 | return 22; | |
518 | case 'n': | |
519 | case 'N': | |
520 | return 23; | |
521 | case 'o': | |
522 | case 'O': | |
523 | return 24; | |
524 | case 'p': | |
525 | case 'P': | |
526 | return 25; | |
527 | case 'q': | |
528 | case 'Q': | |
529 | return 26; | |
530 | case 'r': | |
531 | case 'R': | |
532 | return 27; | |
533 | case 's': | |
534 | case 'S': | |
535 | return 28; | |
536 | case 't': | |
537 | case 'T': | |
538 | return 29; | |
539 | case 'u': | |
540 | case 'U': | |
541 | return 30; | |
542 | case 'v': | |
543 | case 'V': | |
544 | return 31; | |
545 | case 'w': | |
546 | case 'W': | |
547 | return 32; | |
548 | case 'x': | |
549 | case 'X': | |
550 | return 33; | |
551 | case 'y': | |
552 | case 'Y': | |
553 | return 34; | |
554 | case 'z': | |
555 | case 'Z': | |
556 | return 35; | |
557 | } | |
558 | return std::numeric_limits<unsigned char>::max(); | |
559 | } | |
560 | ||
561 | /// std::from_chars implementation for integers in bases 11 to 26. | |
562 | template<typename _Tp> | |
563 | bool | |
564 | __from_chars_alnum(const char*& __first, const char* __last, _Tp& __val, | |
565 | int __base) | |
566 | { | |
567 | bool __valid = true; | |
568 | while (__first != __last) | |
569 | { | |
570 | unsigned char __c = *__first; | |
571 | if (std::isdigit(__c)) | |
572 | __c -= '0'; | |
573 | else | |
574 | { | |
575 | __c = __from_chars_alpha_to_num(__c); | |
576 | if (__c >= __base) | |
577 | break; | |
578 | } | |
579 | ||
580 | if (__builtin_expect(__valid, 1)) | |
581 | __valid = __raise_and_add(__val, __base, __c); | |
582 | __first++; | |
583 | } | |
584 | return __valid; | |
585 | } | |
586 | ||
587 | template<typename _Tp> | |
588 | using __integer_from_chars_result_type | |
589 | = enable_if_t<__is_int_to_chars_type<_Tp>::value, from_chars_result>; | |
590 | ||
591 | } // namespace __detail | |
592 | ||
593 | /// std::from_chars for integral types. | |
594 | template<typename _Tp> | |
595 | __detail::__integer_from_chars_result_type<_Tp> | |
596 | from_chars(const char* __first, const char* __last, _Tp& __value, | |
597 | int __base = 10) | |
598 | { | |
599 | __glibcxx_assert(2 <= __base && __base <= 36); | |
600 | ||
601 | from_chars_result __res{__first, {}}; | |
602 | ||
603 | int __sign = 1; | |
604 | if _GLIBCXX17_CONSTEXPR (std::is_signed<_Tp>::value) | |
605 | if (__first != __last && *__first == '-') | |
606 | { | |
607 | __sign = -1; | |
608 | ++__first; | |
609 | } | |
610 | ||
611 | using _Up = __detail::__unsigned_least_t<_Tp>; | |
612 | _Up __val = 0; | |
613 | ||
614 | const auto __start = __first; | |
615 | bool __valid; | |
616 | if (__base == 2) | |
617 | __valid = __detail::__from_chars_binary(__first, __last, __val); | |
618 | else if (__base <= 10) | |
619 | __valid = __detail::__from_chars_digit(__first, __last, __val, __base); | |
620 | else | |
621 | __valid = __detail::__from_chars_alnum(__first, __last, __val, __base); | |
622 | ||
623 | if (__builtin_expect(__first == __start, 0)) | |
624 | __res.ec = errc::invalid_argument; | |
625 | else | |
626 | { | |
627 | __res.ptr = __first; | |
628 | if (!__valid) | |
629 | __res.ec = errc::result_out_of_range; | |
630 | else | |
631 | { | |
632 | if _GLIBCXX17_CONSTEXPR (std::is_signed<_Tp>::value) | |
633 | { | |
634 | _Tp __tmp; | |
635 | if (__builtin_mul_overflow(__val, __sign, &__tmp)) | |
636 | __res.ec = errc::result_out_of_range; | |
637 | else | |
638 | __value = __tmp; | |
639 | } | |
640 | else | |
641 | { | |
642 | if _GLIBCXX17_CONSTEXPR | |
643 | (numeric_limits<_Up>::max() > numeric_limits<_Tp>::max()) | |
644 | { | |
645 | if (__val > numeric_limits<_Tp>::max()) | |
646 | __res.ec = errc::result_out_of_range; | |
647 | else | |
648 | __value = __val; | |
649 | } | |
650 | else | |
651 | __value = __val; | |
652 | } | |
653 | } | |
654 | } | |
655 | return __res; | |
656 | } | |
657 | ||
658 | _GLIBCXX_END_NAMESPACE_VERSION | |
659 | } // namespace std | |
660 | #endif // C++14 | |
661 | #endif // _GLIBCXX_CHARCONV |