xref: /freebsd-12.1/contrib/libc++/include/numeric (revision 24d58133) 
1// -*- C++ -*-
2//===---------------------------- numeric ---------------------------------===//
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_NUMERIC
12#define _LIBCPP_NUMERIC
13
14/*
15    numeric synopsis
16
17namespace std
18{
19
20template <class InputIterator, class T>
21    T
22    accumulate(InputIterator first, InputIterator last, T init);
23
24template <class InputIterator, class T, class BinaryOperation>
25    T
26    accumulate(InputIterator first, InputIterator last, T init, BinaryOperation binary_op);
27
28template<class InputIterator>
29    typename iterator_traits<InputIterator>::value_type
30    reduce(InputIterator first, InputIterator last);  // C++17
31
32template<class InputIterator, class T>
33    T
34    reduce(InputIterator first, InputIterator last, T init);  // C++17
35
36template<class InputIterator, class T, class BinaryOperation>
37    T
38    reduce(InputIterator first, InputIterator last, T init, BinaryOperation binary_op);  // C++17
39
40template <class InputIterator1, class InputIterator2, class T>
41    T
42    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, T init);
43
44template <class InputIterator1, class InputIterator2, class T, class BinaryOperation1, class BinaryOperation2>
45    T
46    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
47                  T init, BinaryOperation1 binary_op1, BinaryOperation2 binary_op2);
48
49
50template<class InputIterator1, class InputIterator2, class T>
51    T
52    transform_reduce(InputIterator1 first1, InputIterator1 last1,
53                     InputIterator2 first2, T init);  // C++17
54
55template<class InputIterator1, class InputIterator2, class T, class BinaryOperation1, class BinaryOperation2>
56    T
57    transform_reduce(InputIterator1 first1, InputIterator1 last1,
58                     InputIterator2 first2, T init,
59                     BinaryOperation1 binary_op1, BinaryOperation2 binary_op2);  // C++17
60
61template<class InputIterator, class T, class BinaryOperation, class UnaryOperation>
62    T
63    transform_reduce(InputIterator first, InputIterator last, T init,
64                     BinaryOperation binary_op, UnaryOperation unary_op);  // C++17
65
66template <class InputIterator, class OutputIterator>
67    OutputIterator
68    partial_sum(InputIterator first, InputIterator last, OutputIterator result);
69
70template <class InputIterator, class OutputIterator, class BinaryOperation>
71    OutputIterator
72    partial_sum(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
73
74template<class InputIterator, class OutputIterator, class T>
75    OutputIterator
76    exclusive_scan(InputIterator first, InputIterator last,
77                   OutputIterator result, T init); // C++17
78
79template<class InputIterator, class OutputIterator, class T, class BinaryOperation>
80    OutputIterator
81    exclusive_scan(InputIterator first, InputIterator last,
82                   OutputIterator result, T init, BinaryOperation binary_op); // C++17
83
84template<class InputIterator, class OutputIterator, class T,
85         class BinaryOperation, class UnaryOperation>
86    OutputIterator
87    transform_exclusive_scan(InputIterator first, InputIterator last,
88                             OutputIterator result, T init,
89                             BinaryOperation binary_op, UnaryOperation unary_op);  // C++17
90
91template <class InputIterator, class OutputIterator>
92    OutputIterator
93    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result);
94
95template <class InputIterator, class OutputIterator, class BinaryOperation>
96    OutputIterator
97    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
98
99template <class ForwardIterator, class T>
100    void iota(ForwardIterator first, ForwardIterator last, T value);
101
102template <class M, class N>
103    constexpr common_type_t<M,N> gcd(M m, N n);    // C++17
104
105template <class M, class N>
106    constexpr common_type_t<M,N> lcm(M m, N n);    // C++17
107
108}  // std
109
110*/
111
112#include <__config>
113#include <iterator>
114#include <limits> // for numeric_limits
115#include <functional>
116
117#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
118#pragma GCC system_header
119#endif
120
121_LIBCPP_PUSH_MACROS
122#include <__undef_macros>
123
124_LIBCPP_BEGIN_NAMESPACE_STD
125
126template <class _InputIterator, class _Tp>
127inline _LIBCPP_INLINE_VISIBILITY
128_Tp
129accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
130{
131    for (; __first != __last; ++__first)
132        __init = __init + *__first;
133    return __init;
134}
135
136template <class _InputIterator, class _Tp, class _BinaryOperation>
137inline _LIBCPP_INLINE_VISIBILITY
138_Tp
139accumulate(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOperation __binary_op)
140{
141    for (; __first != __last; ++__first)
142        __init = __binary_op(__init, *__first);
143    return __init;
144}
145
146#if _LIBCPP_STD_VER > 14
147template <class _InputIterator, class _Tp, class _BinaryOp>
148inline _LIBCPP_INLINE_VISIBILITY
149_Tp
150reduce(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOp __b)
151{
152    for (; __first != __last; ++__first)
153        __init = __b(__init, *__first);
154    return __init;
155}
156
157template <class _InputIterator, class _Tp>
158inline _LIBCPP_INLINE_VISIBILITY
159_Tp
160reduce(_InputIterator __first, _InputIterator __last, _Tp __init)
161{
162    return _VSTD::reduce(__first, __last, __init, _VSTD::plus<>());
163}
164
165template <class _InputIterator>
166inline _LIBCPP_INLINE_VISIBILITY
167typename iterator_traits<_InputIterator>::value_type
168reduce(_InputIterator __first, _InputIterator __last)
169{
170    return _VSTD::reduce(__first, __last,
171       typename iterator_traits<_InputIterator>::value_type{});
172}
173#endif
174
175template <class _InputIterator1, class _InputIterator2, class _Tp>
176inline _LIBCPP_INLINE_VISIBILITY
177_Tp
178inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _Tp __init)
179{
180    for (; __first1 != __last1; ++__first1, (void) ++__first2)
181        __init = __init + *__first1 * *__first2;
182    return __init;
183}
184
185template <class _InputIterator1, class _InputIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
186inline _LIBCPP_INLINE_VISIBILITY
187_Tp
188inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
189              _Tp __init, _BinaryOperation1 __binary_op1, _BinaryOperation2 __binary_op2)
190{
191    for (; __first1 != __last1; ++__first1, (void) ++__first2)
192        __init = __binary_op1(__init, __binary_op2(*__first1, *__first2));
193    return __init;
194}
195
196#if _LIBCPP_STD_VER > 14
197template <class _InputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
198inline _LIBCPP_INLINE_VISIBILITY
199_Tp
200transform_reduce(_InputIterator __first, _InputIterator __last,
201           _Tp __init,  _BinaryOp __b, _UnaryOp __u)
202{
203    for (; __first != __last; ++__first)
204        __init = __b(__init, __u(*__first));
205    return __init;
206}
207
208template <class _InputIterator1, class _InputIterator2,
209          class _Tp, class _BinaryOp1, class _BinaryOp2>
210inline _LIBCPP_INLINE_VISIBILITY
211_Tp
212transform_reduce(_InputIterator1 __first1, _InputIterator1 __last1,
213                 _InputIterator2 __first2, _Tp __init,  _BinaryOp1 __b1, _BinaryOp2 __b2)
214{
215    for (; __first1 != __last1; ++__first1, (void) ++__first2)
216        __init = __b1(__init, __b2(*__first1, *__first2));
217    return __init;
218}
219
220template <class _InputIterator1, class _InputIterator2, class _Tp>
221inline _LIBCPP_INLINE_VISIBILITY
222_Tp
223transform_reduce(_InputIterator1 __first1, _InputIterator1 __last1,
224                 _InputIterator2 __first2, _Tp __init)
225{
226    return _VSTD::transform_reduce(__first1, __last1, __first2, __init,
227                                   _VSTD::plus<>(), _VSTD::multiplies<>());
228}
229#endif
230
231template <class _InputIterator, class _OutputIterator>
232inline _LIBCPP_INLINE_VISIBILITY
233_OutputIterator
234partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
235{
236    if (__first != __last)
237    {
238        typename iterator_traits<_InputIterator>::value_type __t(*__first);
239        *__result = __t;
240        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
241        {
242            __t = __t + *__first;
243            *__result = __t;
244        }
245    }
246    return __result;
247}
248
249template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
250inline _LIBCPP_INLINE_VISIBILITY
251_OutputIterator
252partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
253              _BinaryOperation __binary_op)
254{
255    if (__first != __last)
256    {
257        typename iterator_traits<_InputIterator>::value_type __t(*__first);
258        *__result = __t;
259        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
260        {
261            __t = __binary_op(__t, *__first);
262            *__result = __t;
263        }
264    }
265    return __result;
266}
267
268#if _LIBCPP_STD_VER > 14
269template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
270inline _LIBCPP_INLINE_VISIBILITY
271_OutputIterator
272exclusive_scan(_InputIterator __first, _InputIterator __last,
273               _OutputIterator __result, _Tp __init, _BinaryOp __b)
274{
275    if (__first != __last)
276    {
277        _Tp __saved = __init;
278        do
279        {
280            __init = __b(__init, *__first);
281            *__result = __saved;
282            __saved = __init;
283            ++__result;
284        } while (++__first != __last);
285    }
286    return __result;
287}
288
289template <class _InputIterator, class _OutputIterator, class _Tp>
290inline _LIBCPP_INLINE_VISIBILITY
291_OutputIterator
292exclusive_scan(_InputIterator __first, _InputIterator __last,
293               _OutputIterator __result, _Tp __init)
294{
295    return _VSTD::exclusive_scan(__first, __last, __result, __init, _VSTD::plus<>());
296}
297
298template <class _InputIterator, class _OutputIterator, class _Tp,
299          class _BinaryOp, class _UnaryOp>
300inline _LIBCPP_INLINE_VISIBILITY
301_OutputIterator
302transform_exclusive_scan(_InputIterator __first, _InputIterator __last,
303                           _OutputIterator __result, _Tp __init,
304                           _BinaryOp __b, _UnaryOp __u)
305{
306    if (__first != __last)
307    {
308        _Tp __saved = __init;
309        do
310        {
311            __init = __b(__init, __u(*__first));
312            *__result = __saved;
313            __saved = __init;
314            ++__result;
315        } while (++__first != __last);
316    }
317    return __result;
318}
319#endif
320
321template <class _InputIterator, class _OutputIterator>
322inline _LIBCPP_INLINE_VISIBILITY
323_OutputIterator
324adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
325{
326    if (__first != __last)
327    {
328        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
329        *__result = __t1;
330        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
331        {
332            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
333            *__result = __t2 - __t1;
334            __t1 = _VSTD::move(__t2);
335        }
336    }
337    return __result;
338}
339
340template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
341inline _LIBCPP_INLINE_VISIBILITY
342_OutputIterator
343adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
344                      _BinaryOperation __binary_op)
345{
346    if (__first != __last)
347    {
348        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
349        *__result = __t1;
350        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
351        {
352            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
353            *__result = __binary_op(__t2, __t1);
354            __t1 = _VSTD::move(__t2);
355        }
356    }
357    return __result;
358}
359
360template <class _ForwardIterator, class _Tp>
361inline _LIBCPP_INLINE_VISIBILITY
362void
363iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value_)
364{
365    for (; __first != __last; ++__first, (void) ++__value_)
366        *__first = __value_;
367}
368
369
370#if _LIBCPP_STD_VER > 14
371template <typename _Result, typename _Source, bool _IsSigned = is_signed<_Source>::value> struct __abs;
372
373template <typename _Result, typename _Source>
374struct __abs<_Result, _Source, true> {
375    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
376    _Result operator()(_Source __t) const noexcept
377    {
378    if (__t >= 0) return __t;
379    if (__t == numeric_limits<_Source>::min()) return -static_cast<_Result>(__t);
380    return -__t;
381    }
382};
383
384template <typename _Result, typename _Source>
385struct __abs<_Result, _Source, false> {
386    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
387    _Result operator()(_Source __t) const noexcept { return __t; }
388};
389
390
391template<class _Tp>
392_LIBCPP_CONSTEXPR _LIBCPP_HIDDEN
393_Tp __gcd(_Tp __m, _Tp __n)
394{
395    static_assert((!is_signed<_Tp>::value), "");
396    return __n == 0 ? __m : _VSTD::__gcd<_Tp>(__n, __m % __n);
397}
398
399
400template<class _Tp, class _Up>
401_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
402common_type_t<_Tp,_Up>
403gcd(_Tp __m, _Up __n)
404{
405    static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to gcd must be integer types");
406    static_assert((!is_same<typename remove_cv<_Tp>::type, bool>::value), "First argument to gcd cannot be bool" );
407    static_assert((!is_same<typename remove_cv<_Up>::type, bool>::value), "Second argument to gcd cannot be bool" );
408    using _Rp = common_type_t<_Tp,_Up>;
409    using _Wp = make_unsigned_t<_Rp>;
410    return static_cast<_Rp>(_VSTD::__gcd(
411        static_cast<_Wp>(__abs<_Rp, _Tp>()(__m)),
412        static_cast<_Wp>(__abs<_Rp, _Up>()(__n))));
413}
414
415template<class _Tp, class _Up>
416_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
417common_type_t<_Tp,_Up>
418lcm(_Tp __m, _Up __n)
419{
420    static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to lcm must be integer types");
421    static_assert((!is_same<typename remove_cv<_Tp>::type, bool>::value), "First argument to lcm cannot be bool" );
422    static_assert((!is_same<typename remove_cv<_Up>::type, bool>::value), "Second argument to lcm cannot be bool" );
423    if (__m == 0 || __n == 0)
424        return 0;
425
426    using _Rp = common_type_t<_Tp,_Up>;
427    _Rp __val1 = __abs<_Rp, _Tp>()(__m) / _VSTD::gcd(__m, __n);
428    _Rp __val2 = __abs<_Rp, _Up>()(__n);
429    _LIBCPP_ASSERT((numeric_limits<_Rp>::max() / __val1 > __val2), "Overflow in lcm");
430    return __val1 * __val2;
431}
432
433#endif /* _LIBCPP_STD_VER > 14 */
434
435_LIBCPP_END_NAMESPACE_STD
436
437_LIBCPP_POP_MACROS
438
439#endif  // _LIBCPP_NUMERIC
440