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      1 // -*- C++ -*-
      2 //===---------------------------- ratio -----------------------------------===//
      3 //
      4 //                     The LLVM Compiler Infrastructure
      5 //
      6 // This file is dual licensed under the MIT and the University of Illinois Open
      7 // Source Licenses. See LICENSE.TXT for details.
      8 //
      9 //===----------------------------------------------------------------------===//
     10 
     11 #ifndef _LIBCPP_RATIO
     12 #define _LIBCPP_RATIO
     13 
     14 /*
     15     ratio synopsis
     16 
     17 namespace std
     18 {
     19 
     20 template <intmax_t N, intmax_t D = 1>
     21 class ratio
     22 {
     23 public:
     24     static constexpr intmax_t num;
     25     static constexpr intmax_t den;
     26     typedef ratio<num, den> type;
     27 };
     28 
     29 // ratio arithmetic
     30 template <class R1, class R2> using ratio_add = ...;
     31 template <class R1, class R2> using ratio_subtract = ...;
     32 template <class R1, class R2> using ratio_multiply = ...;
     33 template <class R1, class R2> using ratio_divide = ...;
     34 
     35 // ratio comparison
     36 template <class R1, class R2> struct ratio_equal;
     37 template <class R1, class R2> struct ratio_not_equal;
     38 template <class R1, class R2> struct ratio_less;
     39 template <class R1, class R2> struct ratio_less_equal;
     40 template <class R1, class R2> struct ratio_greater;
     41 template <class R1, class R2> struct ratio_greater_equal;
     42 
     43 // convenience SI typedefs
     44 typedef ratio<1, 1000000000000000000000000> yocto;  // not supported
     45 typedef ratio<1,    1000000000000000000000> zepto;  // not supported
     46 typedef ratio<1,       1000000000000000000> atto;
     47 typedef ratio<1,          1000000000000000> femto;
     48 typedef ratio<1,             1000000000000> pico;
     49 typedef ratio<1,                1000000000> nano;
     50 typedef ratio<1,                   1000000> micro;
     51 typedef ratio<1,                      1000> milli;
     52 typedef ratio<1,                       100> centi;
     53 typedef ratio<1,                        10> deci;
     54 typedef ratio<                       10, 1> deca;
     55 typedef ratio<                      100, 1> hecto;
     56 typedef ratio<                     1000, 1> kilo;
     57 typedef ratio<                  1000000, 1> mega;
     58 typedef ratio<               1000000000, 1> giga;
     59 typedef ratio<            1000000000000, 1> tera;
     60 typedef ratio<         1000000000000000, 1> peta;
     61 typedef ratio<      1000000000000000000, 1> exa;
     62 typedef ratio<   1000000000000000000000, 1> zetta;  // not supported
     63 typedef ratio<1000000000000000000000000, 1> yotta;  // not supported
     64 
     65   // 20.11.5, ratio comparison
     66   template <class R1, class R2> inline constexpr bool ratio_equal_v
     67     = ratio_equal<R1, R2>::value;                                       // C++17
     68   template <class R1, class R2> inline constexpr bool ratio_not_equal_v
     69     = ratio_not_equal<R1, R2>::value;                                   // C++17
     70   template <class R1, class R2> inline constexpr bool ratio_less_v
     71     = ratio_less<R1, R2>::value;                                        // C++17
     72   template <class R1, class R2> inline constexpr bool ratio_less_equal_v
     73     = ratio_less_equal<R1, R2>::value;                                  // C++17
     74   template <class R1, class R2> inline constexpr bool ratio_greater_v
     75     = ratio_greater<R1, R2>::value;                                     // C++17
     76   template <class R1, class R2> inline constexpr bool ratio_greater_equal_v
     77     = ratio_greater_equal<R1, R2>::value;                               // C++17
     78 }
     79 */
     80 
     81 #include <__config>
     82 #include <cstdint>
     83 #include <climits>
     84 #include <type_traits>
     85 
     86 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
     87 #pragma GCC system_header
     88 #endif
     89 
     90 _LIBCPP_PUSH_MACROS
     91 #include <__undef_macros>
     92 
     93 
     94 _LIBCPP_BEGIN_NAMESPACE_STD
     95 
     96 // __static_gcd
     97 
     98 template <intmax_t _Xp, intmax_t _Yp>
     99 struct __static_gcd
    100 {
    101     static const intmax_t value = __static_gcd<_Yp, _Xp % _Yp>::value;
    102 };
    103 
    104 template <intmax_t _Xp>
    105 struct __static_gcd<_Xp, 0>
    106 {
    107     static const intmax_t value = _Xp;
    108 };
    109 
    110 template <>
    111 struct __static_gcd<0, 0>
    112 {
    113     static const intmax_t value = 1;
    114 };
    115 
    116 // __static_lcm
    117 
    118 template <intmax_t _Xp, intmax_t _Yp>
    119 struct __static_lcm
    120 {
    121     static const intmax_t value = _Xp / __static_gcd<_Xp, _Yp>::value * _Yp;
    122 };
    123 
    124 template <intmax_t _Xp>
    125 struct __static_abs
    126 {
    127     static const intmax_t value = _Xp < 0 ? -_Xp : _Xp;
    128 };
    129 
    130 template <intmax_t _Xp>
    131 struct __static_sign
    132 {
    133     static const intmax_t value = _Xp == 0 ? 0 : (_Xp < 0 ? -1 : 1);
    134 };
    135 
    136 template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
    137 class __ll_add;
    138 
    139 template <intmax_t _Xp, intmax_t _Yp>
    140 class __ll_add<_Xp, _Yp, 1>
    141 {
    142     static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
    143     static const intmax_t max = -min;
    144 
    145     static_assert(_Xp <= max - _Yp, "overflow in __ll_add");
    146 public:
    147     static const intmax_t value = _Xp + _Yp;
    148 };
    149 
    150 template <intmax_t _Xp, intmax_t _Yp>
    151 class __ll_add<_Xp, _Yp, 0>
    152 {
    153 public:
    154     static const intmax_t value = _Xp;
    155 };
    156 
    157 template <intmax_t _Xp, intmax_t _Yp>
    158 class __ll_add<_Xp, _Yp, -1>
    159 {
    160     static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
    161     static const intmax_t max = -min;
    162 
    163     static_assert(min - _Yp <= _Xp, "overflow in __ll_add");
    164 public:
    165     static const intmax_t value = _Xp + _Yp;
    166 };
    167 
    168 template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
    169 class __ll_sub;
    170 
    171 template <intmax_t _Xp, intmax_t _Yp>
    172 class __ll_sub<_Xp, _Yp, 1>
    173 {
    174     static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
    175     static const intmax_t max = -min;
    176 
    177     static_assert(min + _Yp <= _Xp, "overflow in __ll_sub");
    178 public:
    179     static const intmax_t value = _Xp - _Yp;
    180 };
    181 
    182 template <intmax_t _Xp, intmax_t _Yp>
    183 class __ll_sub<_Xp, _Yp, 0>
    184 {
    185 public:
    186     static const intmax_t value = _Xp;
    187 };
    188 
    189 template <intmax_t _Xp, intmax_t _Yp>
    190 class __ll_sub<_Xp, _Yp, -1>
    191 {
    192     static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
    193     static const intmax_t max = -min;
    194 
    195     static_assert(_Xp <= max + _Yp, "overflow in __ll_sub");
    196 public:
    197     static const intmax_t value = _Xp - _Yp;
    198 };
    199 
    200 template <intmax_t _Xp, intmax_t _Yp>
    201 class __ll_mul
    202 {
    203     static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
    204     static const intmax_t min = nan + 1;
    205     static const intmax_t max = -min;
    206     static const intmax_t __a_x = __static_abs<_Xp>::value;
    207     static const intmax_t __a_y = __static_abs<_Yp>::value;
    208 
    209     static_assert(_Xp != nan && _Yp != nan && __a_x <= max / __a_y, "overflow in __ll_mul");
    210 public:
    211     static const intmax_t value = _Xp * _Yp;
    212 };
    213 
    214 template <intmax_t _Yp>
    215 class __ll_mul<0, _Yp>
    216 {
    217 public:
    218     static const intmax_t value = 0;
    219 };
    220 
    221 template <intmax_t _Xp>
    222 class __ll_mul<_Xp, 0>
    223 {
    224 public:
    225     static const intmax_t value = 0;
    226 };
    227 
    228 template <>
    229 class __ll_mul<0, 0>
    230 {
    231 public:
    232     static const intmax_t value = 0;
    233 };
    234 
    235 // Not actually used but left here in case needed in future maintenance
    236 template <intmax_t _Xp, intmax_t _Yp>
    237 class __ll_div
    238 {
    239     static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
    240     static const intmax_t min = nan + 1;
    241     static const intmax_t max = -min;
    242 
    243     static_assert(_Xp != nan && _Yp != nan && _Yp != 0, "overflow in __ll_div");
    244 public:
    245     static const intmax_t value = _Xp / _Yp;
    246 };
    247 
    248 template <intmax_t _Num, intmax_t _Den = 1>
    249 class _LIBCPP_TEMPLATE_VIS ratio
    250 {
    251     static_assert(__static_abs<_Num>::value >= 0, "ratio numerator is out of range");
    252     static_assert(_Den != 0, "ratio divide by 0");
    253     static_assert(__static_abs<_Den>::value >  0, "ratio denominator is out of range");
    254     static _LIBCPP_CONSTEXPR const intmax_t __na = __static_abs<_Num>::value;
    255     static _LIBCPP_CONSTEXPR const intmax_t __da = __static_abs<_Den>::value;
    256     static _LIBCPP_CONSTEXPR const intmax_t __s = __static_sign<_Num>::value * __static_sign<_Den>::value;
    257     static _LIBCPP_CONSTEXPR const intmax_t __gcd = __static_gcd<__na, __da>::value;
    258 public:
    259     static _LIBCPP_CONSTEXPR const intmax_t num = __s * __na / __gcd;
    260     static _LIBCPP_CONSTEXPR const intmax_t den = __da / __gcd;
    261 
    262     typedef ratio<num, den> type;
    263 };
    264 
    265 template <intmax_t _Num, intmax_t _Den>
    266 _LIBCPP_CONSTEXPR const intmax_t ratio<_Num, _Den>::num;
    267 
    268 template <intmax_t _Num, intmax_t _Den>
    269 _LIBCPP_CONSTEXPR const intmax_t ratio<_Num, _Den>::den;
    270 
    271 template <class _Tp>                    struct __is_ratio                     : false_type {};
    272 template <intmax_t _Num, intmax_t _Den> struct __is_ratio<ratio<_Num, _Den> > : true_type  {};
    273 
    274 typedef ratio<1LL, 1000000000000000000LL> atto;
    275 typedef ratio<1LL,    1000000000000000LL> femto;
    276 typedef ratio<1LL,       1000000000000LL> pico;
    277 typedef ratio<1LL,          1000000000LL> nano;
    278 typedef ratio<1LL,             1000000LL> micro;
    279 typedef ratio<1LL,                1000LL> milli;
    280 typedef ratio<1LL,                 100LL> centi;
    281 typedef ratio<1LL,                  10LL> deci;
    282 typedef ratio<                 10LL, 1LL> deca;
    283 typedef ratio<                100LL, 1LL> hecto;
    284 typedef ratio<               1000LL, 1LL> kilo;
    285 typedef ratio<            1000000LL, 1LL> mega;
    286 typedef ratio<         1000000000LL, 1LL> giga;
    287 typedef ratio<      1000000000000LL, 1LL> tera;
    288 typedef ratio<   1000000000000000LL, 1LL> peta;
    289 typedef ratio<1000000000000000000LL, 1LL> exa;
    290 
    291 template <class _R1, class _R2>
    292 struct __ratio_multiply
    293 {
    294 private:
    295     static const intmax_t __gcd_n1_d2 = __static_gcd<_R1::num, _R2::den>::value;
    296     static const intmax_t __gcd_d1_n2 = __static_gcd<_R1::den, _R2::num>::value;
    297 public:
    298     typedef typename ratio
    299         <
    300             __ll_mul<_R1::num / __gcd_n1_d2, _R2::num / __gcd_d1_n2>::value,
    301             __ll_mul<_R2::den / __gcd_n1_d2, _R1::den / __gcd_d1_n2>::value
    302         >::type type;
    303 };
    304 
    305 #ifndef _LIBCPP_CXX03_LANG
    306 
    307 template <class _R1, class _R2> using ratio_multiply
    308                                     = typename __ratio_multiply<_R1, _R2>::type;
    309 
    310 #else  // _LIBCPP_CXX03_LANG
    311 
    312 template <class _R1, class _R2>
    313 struct _LIBCPP_TEMPLATE_VIS ratio_multiply
    314     : public __ratio_multiply<_R1, _R2>::type {};
    315 
    316 #endif  // _LIBCPP_CXX03_LANG
    317 
    318 template <class _R1, class _R2>
    319 struct __ratio_divide
    320 {
    321 private:
    322     static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
    323     static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
    324 public:
    325     typedef typename ratio
    326         <
    327             __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
    328             __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
    329         >::type type;
    330 };
    331 
    332 #ifndef _LIBCPP_CXX03_LANG
    333 
    334 template <class _R1, class _R2> using ratio_divide
    335                                       = typename __ratio_divide<_R1, _R2>::type;
    336 
    337 #else  // _LIBCPP_CXX03_LANG
    338 
    339 template <class _R1, class _R2>
    340 struct _LIBCPP_TEMPLATE_VIS ratio_divide
    341     : public __ratio_divide<_R1, _R2>::type {};
    342 
    343 #endif  // _LIBCPP_CXX03_LANG
    344 
    345 template <class _R1, class _R2>
    346 struct __ratio_add
    347 {
    348 private:
    349     static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
    350     static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
    351 public:
    352     typedef typename ratio_multiply
    353         <
    354             ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
    355             ratio
    356             <
    357                 __ll_add
    358                 <
    359                     __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
    360                     __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
    361                 >::value,
    362                 _R2::den
    363             >
    364         >::type type;
    365 };
    366 
    367 #ifndef _LIBCPP_CXX03_LANG
    368 
    369 template <class _R1, class _R2> using ratio_add
    370                                          = typename __ratio_add<_R1, _R2>::type;
    371 
    372 #else  // _LIBCPP_CXX03_LANG
    373 
    374 template <class _R1, class _R2>
    375 struct _LIBCPP_TEMPLATE_VIS ratio_add
    376     : public __ratio_add<_R1, _R2>::type {};
    377 
    378 #endif  // _LIBCPP_CXX03_LANG
    379 
    380 template <class _R1, class _R2>
    381 struct __ratio_subtract
    382 {
    383 private:
    384     static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
    385     static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
    386 public:
    387     typedef typename ratio_multiply
    388         <
    389             ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
    390             ratio
    391             <
    392                 __ll_sub
    393                 <
    394                     __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
    395                     __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
    396                 >::value,
    397                 _R2::den
    398             >
    399         >::type type;
    400 };
    401 
    402 #ifndef _LIBCPP_CXX03_LANG
    403 
    404 template <class _R1, class _R2> using ratio_subtract
    405                                     = typename __ratio_subtract<_R1, _R2>::type;
    406 
    407 #else  // _LIBCPP_CXX03_LANG
    408 
    409 template <class _R1, class _R2>
    410 struct _LIBCPP_TEMPLATE_VIS ratio_subtract
    411     : public __ratio_subtract<_R1, _R2>::type {};
    412 
    413 #endif  // _LIBCPP_CXX03_LANG
    414 
    415 // ratio_equal
    416 
    417 template <class _R1, class _R2>
    418 struct _LIBCPP_TEMPLATE_VIS ratio_equal
    419     : public _LIBCPP_BOOL_CONSTANT((_R1::num == _R2::num && _R1::den == _R2::den)) {};
    420 
    421 template <class _R1, class _R2>
    422 struct _LIBCPP_TEMPLATE_VIS ratio_not_equal
    423     : public _LIBCPP_BOOL_CONSTANT((!ratio_equal<_R1, _R2>::value)) {};
    424 
    425 // ratio_less
    426 
    427 template <class _R1, class _R2, bool _Odd = false,
    428           intmax_t _Q1 = _R1::num / _R1::den, intmax_t _M1 = _R1::num % _R1::den,
    429           intmax_t _Q2 = _R2::num / _R2::den, intmax_t _M2 = _R2::num % _R2::den>
    430 struct __ratio_less1
    431 {
    432     static const bool value = _Odd ? _Q2 < _Q1 : _Q1 < _Q2;
    433 };
    434 
    435 template <class _R1, class _R2, bool _Odd, intmax_t _Qp>
    436 struct __ratio_less1<_R1, _R2, _Odd, _Qp, 0, _Qp, 0>
    437 {
    438     static const bool value = false;
    439 };
    440 
    441 template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M2>
    442 struct __ratio_less1<_R1, _R2, _Odd, _Qp, 0, _Qp, _M2>
    443 {
    444     static const bool value = !_Odd;
    445 };
    446 
    447 template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M1>
    448 struct __ratio_less1<_R1, _R2, _Odd, _Qp, _M1, _Qp, 0>
    449 {
    450     static const bool value = _Odd;
    451 };
    452 
    453 template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M1,
    454                                                         intmax_t _M2>
    455 struct __ratio_less1<_R1, _R2, _Odd, _Qp, _M1, _Qp, _M2>
    456 {
    457     static const bool value = __ratio_less1<ratio<_R1::den, _M1>,
    458                                             ratio<_R2::den, _M2>, !_Odd>::value;
    459 };
    460 
    461 template <class _R1, class _R2, intmax_t _S1 = __static_sign<_R1::num>::value,
    462                                 intmax_t _S2 = __static_sign<_R2::num>::value>
    463 struct __ratio_less
    464 {
    465     static const bool value = _S1 < _S2;
    466 };
    467 
    468 template <class _R1, class _R2>
    469 struct __ratio_less<_R1, _R2, 1LL, 1LL>
    470 {
    471     static const bool value = __ratio_less1<_R1, _R2>::value;
    472 };
    473 
    474 template <class _R1, class _R2>
    475 struct __ratio_less<_R1, _R2, -1LL, -1LL>
    476 {
    477     static const bool value = __ratio_less1<ratio<-_R2::num, _R2::den>, ratio<-_R1::num, _R1::den> >::value;
    478 };
    479 
    480 template <class _R1, class _R2>
    481 struct _LIBCPP_TEMPLATE_VIS ratio_less
    482     : public _LIBCPP_BOOL_CONSTANT((__ratio_less<_R1, _R2>::value)) {};
    483 
    484 template <class _R1, class _R2>
    485 struct _LIBCPP_TEMPLATE_VIS ratio_less_equal
    486     : public _LIBCPP_BOOL_CONSTANT((!ratio_less<_R2, _R1>::value)) {};
    487 
    488 template <class _R1, class _R2>
    489 struct _LIBCPP_TEMPLATE_VIS ratio_greater
    490     : public _LIBCPP_BOOL_CONSTANT((ratio_less<_R2, _R1>::value)) {};
    491 
    492 template <class _R1, class _R2>
    493 struct _LIBCPP_TEMPLATE_VIS ratio_greater_equal
    494     : public _LIBCPP_BOOL_CONSTANT((!ratio_less<_R1, _R2>::value)) {};
    495 
    496 template <class _R1, class _R2>
    497 struct __ratio_gcd
    498 {
    499     typedef ratio<__static_gcd<_R1::num, _R2::num>::value,
    500                   __static_lcm<_R1::den, _R2::den>::value> type;
    501 };
    502 
    503 #if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
    504 template <class _R1, class _R2>
    505 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_equal_v
    506     = ratio_equal<_R1, _R2>::value;
    507 
    508 template <class _R1, class _R2>
    509 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_not_equal_v
    510     = ratio_not_equal<_R1, _R2>::value;
    511 
    512 template <class _R1, class _R2>
    513 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_less_v
    514     = ratio_less<_R1, _R2>::value;
    515 
    516 template <class _R1, class _R2>
    517 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_less_equal_v
    518     = ratio_less_equal<_R1, _R2>::value;
    519 
    520 template <class _R1, class _R2>
    521 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_greater_v
    522     = ratio_greater<_R1, _R2>::value;
    523 
    524 template <class _R1, class _R2>
    525 _LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_greater_equal_v
    526     = ratio_greater_equal<_R1, _R2>::value;
    527 #endif
    528 
    529 _LIBCPP_END_NAMESPACE_STD
    530 
    531 _LIBCPP_POP_MACROS
    532 
    533 #endif  // _LIBCPP_RATIO
    534