ratio revision 1.1 1 // -*- C++ -*-
2 //===---------------------------- ratio -----------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9
10 #ifndef _LIBCPP_RATIO
11 #define _LIBCPP_RATIO
12
13 /*
14 ratio synopsis
15
16 namespace std
17 {
18
19 template <intmax_t N, intmax_t D = 1>
20 class ratio
21 {
22 public:
23 static constexpr intmax_t num;
24 static constexpr intmax_t den;
25 typedef ratio<num, den> type;
26 };
27
28 // ratio arithmetic
29 template <class R1, class R2> using ratio_add = ...;
30 template <class R1, class R2> using ratio_subtract = ...;
31 template <class R1, class R2> using ratio_multiply = ...;
32 template <class R1, class R2> using ratio_divide = ...;
33
34 // ratio comparison
35 template <class R1, class R2> struct ratio_equal;
36 template <class R1, class R2> struct ratio_not_equal;
37 template <class R1, class R2> struct ratio_less;
38 template <class R1, class R2> struct ratio_less_equal;
39 template <class R1, class R2> struct ratio_greater;
40 template <class R1, class R2> struct ratio_greater_equal;
41
42 // convenience SI typedefs
43 typedef ratio<1, 1000000000000000000000000> yocto; // not supported
44 typedef ratio<1, 1000000000000000000000> zepto; // not supported
45 typedef ratio<1, 1000000000000000000> atto;
46 typedef ratio<1, 1000000000000000> femto;
47 typedef ratio<1, 1000000000000> pico;
48 typedef ratio<1, 1000000000> nano;
49 typedef ratio<1, 1000000> micro;
50 typedef ratio<1, 1000> milli;
51 typedef ratio<1, 100> centi;
52 typedef ratio<1, 10> deci;
53 typedef ratio< 10, 1> deca;
54 typedef ratio< 100, 1> hecto;
55 typedef ratio< 1000, 1> kilo;
56 typedef ratio< 1000000, 1> mega;
57 typedef ratio< 1000000000, 1> giga;
58 typedef ratio< 1000000000000, 1> tera;
59 typedef ratio< 1000000000000000, 1> peta;
60 typedef ratio< 1000000000000000000, 1> exa;
61 typedef ratio< 1000000000000000000000, 1> zetta; // not supported
62 typedef ratio<1000000000000000000000000, 1> yotta; // not supported
63
64 // 20.11.5, ratio comparison
65 template <class R1, class R2> inline constexpr bool ratio_equal_v
66 = ratio_equal<R1, R2>::value; // C++17
67 template <class R1, class R2> inline constexpr bool ratio_not_equal_v
68 = ratio_not_equal<R1, R2>::value; // C++17
69 template <class R1, class R2> inline constexpr bool ratio_less_v
70 = ratio_less<R1, R2>::value; // C++17
71 template <class R1, class R2> inline constexpr bool ratio_less_equal_v
72 = ratio_less_equal<R1, R2>::value; // C++17
73 template <class R1, class R2> inline constexpr bool ratio_greater_v
74 = ratio_greater<R1, R2>::value; // C++17
75 template <class R1, class R2> inline constexpr bool ratio_greater_equal_v
76 = ratio_greater_equal<R1, R2>::value; // C++17
77 }
78 */
79
80 #include <__config>
81 #include <cstdint>
82 #include <climits>
83 #include <type_traits>
84
85 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
86 #pragma GCC system_header
87 #endif
88
89 _LIBCPP_PUSH_MACROS
90 #include <__undef_macros>
91
92
93 _LIBCPP_BEGIN_NAMESPACE_STD
94
95 // __static_gcd
96
97 template <intmax_t _Xp, intmax_t _Yp>
98 struct __static_gcd
99 {
100 static const intmax_t value = __static_gcd<_Yp, _Xp % _Yp>::value;
101 };
102
103 template <intmax_t _Xp>
104 struct __static_gcd<_Xp, 0>
105 {
106 static const intmax_t value = _Xp;
107 };
108
109 template <>
110 struct __static_gcd<0, 0>
111 {
112 static const intmax_t value = 1;
113 };
114
115 // __static_lcm
116
117 template <intmax_t _Xp, intmax_t _Yp>
118 struct __static_lcm
119 {
120 static const intmax_t value = _Xp / __static_gcd<_Xp, _Yp>::value * _Yp;
121 };
122
123 template <intmax_t _Xp>
124 struct __static_abs
125 {
126 static const intmax_t value = _Xp < 0 ? -_Xp : _Xp;
127 };
128
129 template <intmax_t _Xp>
130 struct __static_sign
131 {
132 static const intmax_t value = _Xp == 0 ? 0 : (_Xp < 0 ? -1 : 1);
133 };
134
135 template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
136 class __ll_add;
137
138 template <intmax_t _Xp, intmax_t _Yp>
139 class __ll_add<_Xp, _Yp, 1>
140 {
141 static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
142 static const intmax_t max = -min;
143
144 static_assert(_Xp <= max - _Yp, "overflow in __ll_add");
145 public:
146 static const intmax_t value = _Xp + _Yp;
147 };
148
149 template <intmax_t _Xp, intmax_t _Yp>
150 class __ll_add<_Xp, _Yp, 0>
151 {
152 public:
153 static const intmax_t value = _Xp;
154 };
155
156 template <intmax_t _Xp, intmax_t _Yp>
157 class __ll_add<_Xp, _Yp, -1>
158 {
159 static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
160 static const intmax_t max = -min;
161
162 static_assert(min - _Yp <= _Xp, "overflow in __ll_add");
163 public:
164 static const intmax_t value = _Xp + _Yp;
165 };
166
167 template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
168 class __ll_sub;
169
170 template <intmax_t _Xp, intmax_t _Yp>
171 class __ll_sub<_Xp, _Yp, 1>
172 {
173 static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
174 static const intmax_t max = -min;
175
176 static_assert(min + _Yp <= _Xp, "overflow in __ll_sub");
177 public:
178 static const intmax_t value = _Xp - _Yp;
179 };
180
181 template <intmax_t _Xp, intmax_t _Yp>
182 class __ll_sub<_Xp, _Yp, 0>
183 {
184 public:
185 static const intmax_t value = _Xp;
186 };
187
188 template <intmax_t _Xp, intmax_t _Yp>
189 class __ll_sub<_Xp, _Yp, -1>
190 {
191 static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
192 static const intmax_t max = -min;
193
194 static_assert(_Xp <= max + _Yp, "overflow in __ll_sub");
195 public:
196 static const intmax_t value = _Xp - _Yp;
197 };
198
199 template <intmax_t _Xp, intmax_t _Yp>
200 class __ll_mul
201 {
202 static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
203 static const intmax_t min = nan + 1;
204 static const intmax_t max = -min;
205 static const intmax_t __a_x = __static_abs<_Xp>::value;
206 static const intmax_t __a_y = __static_abs<_Yp>::value;
207
208 static_assert(_Xp != nan && _Yp != nan && __a_x <= max / __a_y, "overflow in __ll_mul");
209 public:
210 static const intmax_t value = _Xp * _Yp;
211 };
212
213 template <intmax_t _Yp>
214 class __ll_mul<0, _Yp>
215 {
216 public:
217 static const intmax_t value = 0;
218 };
219
220 template <intmax_t _Xp>
221 class __ll_mul<_Xp, 0>
222 {
223 public:
224 static const intmax_t value = 0;
225 };
226
227 template <>
228 class __ll_mul<0, 0>
229 {
230 public:
231 static const intmax_t value = 0;
232 };
233
234 // Not actually used but left here in case needed in future maintenance
235 template <intmax_t _Xp, intmax_t _Yp>
236 class __ll_div
237 {
238 static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
239 static const intmax_t min = nan + 1;
240 static const intmax_t max = -min;
241
242 static_assert(_Xp != nan && _Yp != nan && _Yp != 0, "overflow in __ll_div");
243 public:
244 static const intmax_t value = _Xp / _Yp;
245 };
246
247 template <intmax_t _Num, intmax_t _Den = 1>
248 class _LIBCPP_TEMPLATE_VIS ratio
249 {
250 static_assert(__static_abs<_Num>::value >= 0, "ratio numerator is out of range");
251 static_assert(_Den != 0, "ratio divide by 0");
252 static_assert(__static_abs<_Den>::value > 0, "ratio denominator is out of range");
253 static _LIBCPP_CONSTEXPR const intmax_t __na = __static_abs<_Num>::value;
254 static _LIBCPP_CONSTEXPR const intmax_t __da = __static_abs<_Den>::value;
255 static _LIBCPP_CONSTEXPR const intmax_t __s = __static_sign<_Num>::value * __static_sign<_Den>::value;
256 static _LIBCPP_CONSTEXPR const intmax_t __gcd = __static_gcd<__na, __da>::value;
257 public:
258 static _LIBCPP_CONSTEXPR const intmax_t num = __s * __na / __gcd;
259 static _LIBCPP_CONSTEXPR const intmax_t den = __da / __gcd;
260
261 typedef ratio<num, den> type;
262 };
263
264 template <intmax_t _Num, intmax_t _Den>
265 _LIBCPP_CONSTEXPR const intmax_t ratio<_Num, _Den>::num;
266
267 template <intmax_t _Num, intmax_t _Den>
268 _LIBCPP_CONSTEXPR const intmax_t ratio<_Num, _Den>::den;
269
270 template <class _Tp> struct __is_ratio : false_type {};
271 template <intmax_t _Num, intmax_t _Den> struct __is_ratio<ratio<_Num, _Den> > : true_type {};
272
273 typedef ratio<1LL, 1000000000000000000LL> atto;
274 typedef ratio<1LL, 1000000000000000LL> femto;
275 typedef ratio<1LL, 1000000000000LL> pico;
276 typedef ratio<1LL, 1000000000LL> nano;
277 typedef ratio<1LL, 1000000LL> micro;
278 typedef ratio<1LL, 1000LL> milli;
279 typedef ratio<1LL, 100LL> centi;
280 typedef ratio<1LL, 10LL> deci;
281 typedef ratio< 10LL, 1LL> deca;
282 typedef ratio< 100LL, 1LL> hecto;
283 typedef ratio< 1000LL, 1LL> kilo;
284 typedef ratio< 1000000LL, 1LL> mega;
285 typedef ratio< 1000000000LL, 1LL> giga;
286 typedef ratio< 1000000000000LL, 1LL> tera;
287 typedef ratio< 1000000000000000LL, 1LL> peta;
288 typedef ratio<1000000000000000000LL, 1LL> exa;
289
290 template <class _R1, class _R2>
291 struct __ratio_multiply
292 {
293 private:
294 static const intmax_t __gcd_n1_d2 = __static_gcd<_R1::num, _R2::den>::value;
295 static const intmax_t __gcd_d1_n2 = __static_gcd<_R1::den, _R2::num>::value;
296 public:
297 typedef typename ratio
298 <
299 __ll_mul<_R1::num / __gcd_n1_d2, _R2::num / __gcd_d1_n2>::value,
300 __ll_mul<_R2::den / __gcd_n1_d2, _R1::den / __gcd_d1_n2>::value
301 >::type type;
302 };
303
304 #ifndef _LIBCPP_CXX03_LANG
305
306 template <class _R1, class _R2> using ratio_multiply
307 = typename __ratio_multiply<_R1, _R2>::type;
308
309 #else // _LIBCPP_CXX03_LANG
310
311 template <class _R1, class _R2>
312 struct _LIBCPP_TEMPLATE_VIS ratio_multiply
313 : public __ratio_multiply<_R1, _R2>::type {};
314
315 #endif // _LIBCPP_CXX03_LANG
316
317 template <class _R1, class _R2>
318 struct __ratio_divide
319 {
320 private:
321 static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
322 static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
323 public:
324 typedef typename ratio
325 <
326 __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
327 __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
328 >::type type;
329 };
330
331 #ifndef _LIBCPP_CXX03_LANG
332
333 template <class _R1, class _R2> using ratio_divide
334 = typename __ratio_divide<_R1, _R2>::type;
335
336 #else // _LIBCPP_CXX03_LANG
337
338 template <class _R1, class _R2>
339 struct _LIBCPP_TEMPLATE_VIS ratio_divide
340 : public __ratio_divide<_R1, _R2>::type {};
341
342 #endif // _LIBCPP_CXX03_LANG
343
344 template <class _R1, class _R2>
345 struct __ratio_add
346 {
347 private:
348 static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
349 static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
350 public:
351 typedef typename ratio_multiply
352 <
353 ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
354 ratio
355 <
356 __ll_add
357 <
358 __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
359 __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
360 >::value,
361 _R2::den
362 >
363 >::type type;
364 };
365
366 #ifndef _LIBCPP_CXX03_LANG
367
368 template <class _R1, class _R2> using ratio_add
369 = typename __ratio_add<_R1, _R2>::type;
370
371 #else // _LIBCPP_CXX03_LANG
372
373 template <class _R1, class _R2>
374 struct _LIBCPP_TEMPLATE_VIS ratio_add
375 : public __ratio_add<_R1, _R2>::type {};
376
377 #endif // _LIBCPP_CXX03_LANG
378
379 template <class _R1, class _R2>
380 struct __ratio_subtract
381 {
382 private:
383 static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
384 static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
385 public:
386 typedef typename ratio_multiply
387 <
388 ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
389 ratio
390 <
391 __ll_sub
392 <
393 __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
394 __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
395 >::value,
396 _R2::den
397 >
398 >::type type;
399 };
400
401 #ifndef _LIBCPP_CXX03_LANG
402
403 template <class _R1, class _R2> using ratio_subtract
404 = typename __ratio_subtract<_R1, _R2>::type;
405
406 #else // _LIBCPP_CXX03_LANG
407
408 template <class _R1, class _R2>
409 struct _LIBCPP_TEMPLATE_VIS ratio_subtract
410 : public __ratio_subtract<_R1, _R2>::type {};
411
412 #endif // _LIBCPP_CXX03_LANG
413
414 // ratio_equal
415
416 template <class _R1, class _R2>
417 struct _LIBCPP_TEMPLATE_VIS ratio_equal
418 : public _LIBCPP_BOOL_CONSTANT((_R1::num == _R2::num && _R1::den == _R2::den)) {};
419
420 template <class _R1, class _R2>
421 struct _LIBCPP_TEMPLATE_VIS ratio_not_equal
422 : public _LIBCPP_BOOL_CONSTANT((!ratio_equal<_R1, _R2>::value)) {};
423
424 // ratio_less
425
426 template <class _R1, class _R2, bool _Odd = false,
427 intmax_t _Q1 = _R1::num / _R1::den, intmax_t _M1 = _R1::num % _R1::den,
428 intmax_t _Q2 = _R2::num / _R2::den, intmax_t _M2 = _R2::num % _R2::den>
429 struct __ratio_less1
430 {
431 static const bool value = _Odd ? _Q2 < _Q1 : _Q1 < _Q2;
432 };
433
434 template <class _R1, class _R2, bool _Odd, intmax_t _Qp>
435 struct __ratio_less1<_R1, _R2, _Odd, _Qp, 0, _Qp, 0>
436 {
437 static const bool value = false;
438 };
439
440 template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M2>
441 struct __ratio_less1<_R1, _R2, _Odd, _Qp, 0, _Qp, _M2>
442 {
443 static const bool value = !_Odd;
444 };
445
446 template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M1>
447 struct __ratio_less1<_R1, _R2, _Odd, _Qp, _M1, _Qp, 0>
448 {
449 static const bool value = _Odd;
450 };
451
452 template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M1,
453 intmax_t _M2>
454 struct __ratio_less1<_R1, _R2, _Odd, _Qp, _M1, _Qp, _M2>
455 {
456 static const bool value = __ratio_less1<ratio<_R1::den, _M1>,
457 ratio<_R2::den, _M2>, !_Odd>::value;
458 };
459
460 template <class _R1, class _R2, intmax_t _S1 = __static_sign<_R1::num>::value,
461 intmax_t _S2 = __static_sign<_R2::num>::value>
462 struct __ratio_less
463 {
464 static const bool value = _S1 < _S2;
465 };
466
467 template <class _R1, class _R2>
468 struct __ratio_less<_R1, _R2, 1LL, 1LL>
469 {
470 static const bool value = __ratio_less1<_R1, _R2>::value;
471 };
472
473 template <class _R1, class _R2>
474 struct __ratio_less<_R1, _R2, -1LL, -1LL>
475 {
476 static const bool value = __ratio_less1<ratio<-_R2::num, _R2::den>, ratio<-_R1::num, _R1::den> >::value;
477 };
478
479 template <class _R1, class _R2>
480 struct _LIBCPP_TEMPLATE_VIS ratio_less
481 : public _LIBCPP_BOOL_CONSTANT((__ratio_less<_R1, _R2>::value)) {};
482
483 template <class _R1, class _R2>
484 struct _LIBCPP_TEMPLATE_VIS ratio_less_equal
485 : public _LIBCPP_BOOL_CONSTANT((!ratio_less<_R2, _R1>::value)) {};
486
487 template <class _R1, class _R2>
488 struct _LIBCPP_TEMPLATE_VIS ratio_greater
489 : public _LIBCPP_BOOL_CONSTANT((ratio_less<_R2, _R1>::value)) {};
490
491 template <class _R1, class _R2>
492 struct _LIBCPP_TEMPLATE_VIS ratio_greater_equal
493 : public _LIBCPP_BOOL_CONSTANT((!ratio_less<_R1, _R2>::value)) {};
494
495 template <class _R1, class _R2>
496 struct __ratio_gcd
497 {
498 typedef ratio<__static_gcd<_R1::num, _R2::num>::value,
499 __static_lcm<_R1::den, _R2::den>::value> type;
500 };
501
502 #if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
503 template <class _R1, class _R2>
504 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_equal_v
505 = ratio_equal<_R1, _R2>::value;
506
507 template <class _R1, class _R2>
508 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_not_equal_v
509 = ratio_not_equal<_R1, _R2>::value;
510
511 template <class _R1, class _R2>
512 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_less_v
513 = ratio_less<_R1, _R2>::value;
514
515 template <class _R1, class _R2>
516 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_less_equal_v
517 = ratio_less_equal<_R1, _R2>::value;
518
519 template <class _R1, class _R2>
520 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_greater_v
521 = ratio_greater<_R1, _R2>::value;
522
523 template <class _R1, class _R2>
524 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_greater_equal_v
525 = ratio_greater_equal<_R1, _R2>::value;
526 #endif
527
528 _LIBCPP_END_NAMESPACE_STD
529
530 _LIBCPP_POP_MACROS
531
532 #endif // _LIBCPP_RATIO
533