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1 | // Functional extensions -*- C++ -*- |
2 | ||
8fc81078 | 3 | // Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010 |
681a6919 | 4 | // Free Software Foundation, Inc. |
01b0d4b8 PC |
5 | // |
6 | // This file is part of the GNU ISO C++ Library. This library is free | |
7 | // software; you can redistribute it and/or modify it under the | |
8 | // terms of the GNU General Public License as published by the | |
748086b7 | 9 | // Free Software Foundation; either version 3, or (at your option) |
01b0d4b8 PC |
10 | // any later version. |
11 | ||
12 | // This library is distributed in the hope that it will be useful, | |
13 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | // GNU General Public License for more details. | |
16 | ||
748086b7 JJ |
17 | // Under Section 7 of GPL version 3, you are granted additional |
18 | // permissions described in the GCC Runtime Library Exception, version | |
19 | // 3.1, as published by the Free Software Foundation. | |
01b0d4b8 | 20 | |
748086b7 JJ |
21 | // You should have received a copy of the GNU General Public License and |
22 | // a copy of the GCC Runtime Library Exception along with this program; | |
23 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
24 | // <http://www.gnu.org/licenses/>. | |
01b0d4b8 PC |
25 | |
26 | /* | |
27 | * | |
28 | * Copyright (c) 1994 | |
29 | * Hewlett-Packard Company | |
30 | * | |
31 | * Permission to use, copy, modify, distribute and sell this software | |
32 | * and its documentation for any purpose is hereby granted without fee, | |
33 | * provided that the above copyright notice appear in all copies and | |
34 | * that both that copyright notice and this permission notice appear | |
35 | * in supporting documentation. Hewlett-Packard Company makes no | |
36 | * representations about the suitability of this software for any | |
37 | * purpose. It is provided "as is" without express or implied warranty. | |
38 | * | |
39 | * | |
40 | * Copyright (c) 1996 | |
41 | * Silicon Graphics Computer Systems, Inc. | |
42 | * | |
43 | * Permission to use, copy, modify, distribute and sell this software | |
44 | * and its documentation for any purpose is hereby granted without fee, | |
45 | * provided that the above copyright notice appear in all copies and | |
46 | * that both that copyright notice and this permission notice appear | |
47 | * in supporting documentation. Silicon Graphics makes no | |
48 | * representations about the suitability of this software for any | |
49 | * purpose. It is provided "as is" without express or implied warranty. | |
50 | */ | |
51 | ||
ffe94f83 PE |
52 | /** @file ext/functional |
53 | * This file is a GNU extension to the Standard C++ Library (possibly | |
0aa06b18 | 54 | * containing extensions from the HP/SGI STL subset). |
ffe94f83 PE |
55 | */ |
56 | ||
01b0d4b8 | 57 | #ifndef _EXT_FUNCTIONAL |
b2acb86f | 58 | #define _EXT_FUNCTIONAL 1 |
01b0d4b8 PC |
59 | |
60 | #pragma GCC system_header | |
b2acb86f | 61 | |
54c1bf78 | 62 | #include <functional> |
01b0d4b8 | 63 | |
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64 | namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) |
65 | { | |
66 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
3cbc7af0 | 67 | |
05a2763e | 68 | using std::size_t; |
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69 | using std::unary_function; |
70 | using std::binary_function; | |
71 | using std::mem_fun1_t; | |
72 | using std::const_mem_fun1_t; | |
73 | using std::mem_fun1_ref_t; | |
74 | using std::const_mem_fun1_ref_t; | |
75 | ||
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76 | /** The @c identity_element functions are not part of the C++ |
77 | * standard; SGI provided them as an extension. Its argument is an | |
78 | * operation, and its return value is the identity element for that | |
79 | * operation. It is overloaded for addition and multiplication, | |
80 | * and you can overload it for your own nefarious operations. | |
4a787fa8 PC |
81 | * |
82 | * @addtogroup SGIextensions | |
83 | * @{ | |
84 | */ | |
85 | /// An \link SGIextensions SGI extension \endlink. | |
86 | template <class _Tp> | |
87 | inline _Tp | |
88 | identity_element(std::plus<_Tp>) | |
89 | { return _Tp(0); } | |
90 | ||
91 | /// An \link SGIextensions SGI extension \endlink. | |
92 | template <class _Tp> | |
93 | inline _Tp | |
94 | identity_element(std::multiplies<_Tp>) | |
95 | { return _Tp(1); } | |
96 | /** @} */ | |
97 | ||
98 | /** As an extension to the binders, SGI provided composition functors and | |
99 | * wrapper functions to aid in their creation. The @c unary_compose | |
100 | * functor is constructed from two functions/functors, @c f and @c g. | |
101 | * Calling @c operator() with a single argument @c x returns @c f(g(x)). | |
102 | * The function @c compose1 takes the two functions and constructs a | |
103 | * @c unary_compose variable for you. | |
104 | * | |
105 | * @c binary_compose is constructed from three functors, @c f, @c g1, | |
106 | * and @c g2. Its @c operator() returns @c f(g1(x),g2(x)). The function | |
107 | * @compose2 takes f, g1, and g2, and constructs the @c binary_compose | |
108 | * instance for you. For example, if @c f returns an int, then | |
109 | * \code | |
110 | * int answer = (compose2(f,g1,g2))(x); | |
111 | * \endcode | |
112 | * is equivalent to | |
113 | * \code | |
114 | * int temp1 = g1(x); | |
115 | * int temp2 = g2(x); | |
116 | * int answer = f(temp1,temp2); | |
117 | * \endcode | |
118 | * But the first form is more compact, and can be passed around as a | |
119 | * functor to other algorithms. | |
120 | * | |
121 | * @addtogroup SGIextensions | |
122 | * @{ | |
123 | */ | |
124 | /// An \link SGIextensions SGI extension \endlink. | |
125 | template <class _Operation1, class _Operation2> | |
126 | class unary_compose | |
127 | : public unary_function<typename _Operation2::argument_type, | |
128 | typename _Operation1::result_type> | |
129 | { | |
130 | protected: | |
131 | _Operation1 _M_fn1; | |
132 | _Operation2 _M_fn2; | |
133 | ||
134 | public: | |
135 | unary_compose(const _Operation1& __x, const _Operation2& __y) | |
136 | : _M_fn1(__x), _M_fn2(__y) {} | |
137 | ||
138 | typename _Operation1::result_type | |
139 | operator()(const typename _Operation2::argument_type& __x) const | |
140 | { return _M_fn1(_M_fn2(__x)); } | |
141 | }; | |
142 | ||
143 | /// An \link SGIextensions SGI extension \endlink. | |
144 | template <class _Operation1, class _Operation2> | |
145 | inline unary_compose<_Operation1, _Operation2> | |
146 | compose1(const _Operation1& __fn1, const _Operation2& __fn2) | |
147 | { return unary_compose<_Operation1,_Operation2>(__fn1, __fn2); } | |
148 | ||
149 | /// An \link SGIextensions SGI extension \endlink. | |
150 | template <class _Operation1, class _Operation2, class _Operation3> | |
151 | class binary_compose | |
152 | : public unary_function<typename _Operation2::argument_type, | |
153 | typename _Operation1::result_type> | |
154 | { | |
155 | protected: | |
156 | _Operation1 _M_fn1; | |
157 | _Operation2 _M_fn2; | |
158 | _Operation3 _M_fn3; | |
159 | ||
160 | public: | |
161 | binary_compose(const _Operation1& __x, const _Operation2& __y, | |
162 | const _Operation3& __z) | |
163 | : _M_fn1(__x), _M_fn2(__y), _M_fn3(__z) { } | |
164 | ||
165 | typename _Operation1::result_type | |
166 | operator()(const typename _Operation2::argument_type& __x) const | |
167 | { return _M_fn1(_M_fn2(__x), _M_fn3(__x)); } | |
168 | }; | |
169 | ||
170 | /// An \link SGIextensions SGI extension \endlink. | |
171 | template <class _Operation1, class _Operation2, class _Operation3> | |
172 | inline binary_compose<_Operation1, _Operation2, _Operation3> | |
173 | compose2(const _Operation1& __fn1, const _Operation2& __fn2, | |
174 | const _Operation3& __fn3) | |
175 | { return binary_compose<_Operation1, _Operation2, _Operation3> | |
176 | (__fn1, __fn2, __fn3); } | |
177 | /** @} */ | |
178 | ||
179 | /** As an extension, SGI provided a functor called @c identity. When a | |
180 | * functor is required but no operations are desired, this can be used as a | |
181 | * pass-through. Its @c operator() returns its argument unchanged. | |
182 | * | |
183 | * @addtogroup SGIextensions | |
184 | */ | |
185 | template <class _Tp> | |
186 | struct identity : public std::_Identity<_Tp> {}; | |
187 | ||
188 | /** @c select1st and @c select2nd are extensions provided by SGI. Their | |
189 | * @c operator()s | |
190 | * take a @c std::pair as an argument, and return either the first member | |
191 | * or the second member, respectively. They can be used (especially with | |
2a60a9f6 | 192 | * the composition functors) to @a strip data from a sequence before |
4a787fa8 PC |
193 | * performing the remainder of an algorithm. |
194 | * | |
195 | * @addtogroup SGIextensions | |
196 | * @{ | |
197 | */ | |
198 | /// An \link SGIextensions SGI extension \endlink. | |
199 | template <class _Pair> | |
200 | struct select1st : public std::_Select1st<_Pair> {}; | |
201 | ||
202 | /// An \link SGIextensions SGI extension \endlink. | |
203 | template <class _Pair> | |
204 | struct select2nd : public std::_Select2nd<_Pair> {}; | |
205 | /** @} */ | |
206 | ||
207 | // extension documented next | |
208 | template <class _Arg1, class _Arg2> | |
209 | struct _Project1st : public binary_function<_Arg1, _Arg2, _Arg1> | |
210 | { | |
211 | _Arg1 | |
212 | operator()(const _Arg1& __x, const _Arg2&) const | |
213 | { return __x; } | |
214 | }; | |
215 | ||
216 | template <class _Arg1, class _Arg2> | |
217 | struct _Project2nd : public binary_function<_Arg1, _Arg2, _Arg2> | |
218 | { | |
219 | _Arg2 | |
220 | operator()(const _Arg1&, const _Arg2& __y) const | |
221 | { return __y; } | |
222 | }; | |
223 | ||
224 | /** The @c operator() of the @c project1st functor takes two arbitrary | |
225 | * arguments and returns the first one, while @c project2nd returns the | |
226 | * second one. They are extensions provided by SGI. | |
227 | * | |
228 | * @addtogroup SGIextensions | |
229 | * @{ | |
230 | */ | |
231 | ||
232 | /// An \link SGIextensions SGI extension \endlink. | |
233 | template <class _Arg1, class _Arg2> | |
234 | struct project1st : public _Project1st<_Arg1, _Arg2> {}; | |
235 | ||
236 | /// An \link SGIextensions SGI extension \endlink. | |
237 | template <class _Arg1, class _Arg2> | |
238 | struct project2nd : public _Project2nd<_Arg1, _Arg2> {}; | |
239 | /** @} */ | |
240 | ||
241 | // extension documented next | |
242 | template <class _Result> | |
243 | struct _Constant_void_fun | |
244 | { | |
245 | typedef _Result result_type; | |
246 | result_type _M_val; | |
247 | ||
248 | _Constant_void_fun(const result_type& __v) : _M_val(__v) {} | |
249 | ||
250 | const result_type& | |
251 | operator()() const | |
252 | { return _M_val; } | |
253 | }; | |
254 | ||
255 | template <class _Result, class _Argument> | |
256 | struct _Constant_unary_fun | |
257 | { | |
258 | typedef _Argument argument_type; | |
259 | typedef _Result result_type; | |
260 | result_type _M_val; | |
261 | ||
262 | _Constant_unary_fun(const result_type& __v) : _M_val(__v) {} | |
263 | ||
264 | const result_type& | |
265 | operator()(const _Argument&) const | |
266 | { return _M_val; } | |
267 | }; | |
268 | ||
269 | template <class _Result, class _Arg1, class _Arg2> | |
270 | struct _Constant_binary_fun | |
271 | { | |
272 | typedef _Arg1 first_argument_type; | |
273 | typedef _Arg2 second_argument_type; | |
274 | typedef _Result result_type; | |
275 | _Result _M_val; | |
276 | ||
277 | _Constant_binary_fun(const _Result& __v) : _M_val(__v) {} | |
278 | ||
279 | const result_type& | |
280 | operator()(const _Arg1&, const _Arg2&) const | |
281 | { return _M_val; } | |
282 | }; | |
283 | ||
284 | /** These three functors are each constructed from a single arbitrary | |
285 | * variable/value. Later, their @c operator()s completely ignore any | |
286 | * arguments passed, and return the stored value. | |
287 | * - @c constant_void_fun's @c operator() takes no arguments | |
288 | * - @c constant_unary_fun's @c operator() takes one argument (ignored) | |
289 | * - @c constant_binary_fun's @c operator() takes two arguments (ignored) | |
290 | * | |
291 | * The helper creator functions @c constant0, @c constant1, and | |
2a60a9f6 | 292 | * @c constant2 each take a @a result argument and construct variables of |
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293 | * the appropriate functor type. |
294 | * | |
295 | * @addtogroup SGIextensions | |
296 | * @{ | |
297 | */ | |
298 | /// An \link SGIextensions SGI extension \endlink. | |
299 | template <class _Result> | |
300 | struct constant_void_fun | |
301 | : public _Constant_void_fun<_Result> | |
302 | { | |
303 | constant_void_fun(const _Result& __v) | |
304 | : _Constant_void_fun<_Result>(__v) {} | |
305 | }; | |
306 | ||
307 | /// An \link SGIextensions SGI extension \endlink. | |
308 | template <class _Result, class _Argument = _Result> | |
309 | struct constant_unary_fun : public _Constant_unary_fun<_Result, _Argument> | |
310 | { | |
311 | constant_unary_fun(const _Result& __v) | |
312 | : _Constant_unary_fun<_Result, _Argument>(__v) {} | |
313 | }; | |
314 | ||
315 | /// An \link SGIextensions SGI extension \endlink. | |
316 | template <class _Result, class _Arg1 = _Result, class _Arg2 = _Arg1> | |
317 | struct constant_binary_fun | |
318 | : public _Constant_binary_fun<_Result, _Arg1, _Arg2> | |
319 | { | |
320 | constant_binary_fun(const _Result& __v) | |
321 | : _Constant_binary_fun<_Result, _Arg1, _Arg2>(__v) {} | |
322 | }; | |
323 | ||
324 | /// An \link SGIextensions SGI extension \endlink. | |
325 | template <class _Result> | |
326 | inline constant_void_fun<_Result> | |
327 | constant0(const _Result& __val) | |
328 | { return constant_void_fun<_Result>(__val); } | |
329 | ||
330 | /// An \link SGIextensions SGI extension \endlink. | |
331 | template <class _Result> | |
332 | inline constant_unary_fun<_Result, _Result> | |
333 | constant1(const _Result& __val) | |
334 | { return constant_unary_fun<_Result, _Result>(__val); } | |
335 | ||
336 | /// An \link SGIextensions SGI extension \endlink. | |
337 | template <class _Result> | |
338 | inline constant_binary_fun<_Result,_Result,_Result> | |
339 | constant2(const _Result& __val) | |
340 | { return constant_binary_fun<_Result, _Result, _Result>(__val); } | |
341 | /** @} */ | |
342 | ||
343 | /** The @c subtractive_rng class is documented on | |
344 | * <a href="http://www.sgi.com/tech/stl/">SGI's site</a>. | |
345 | * Note that this code assumes that @c int is 32 bits. | |
346 | * | |
347 | * @ingroup SGIextensions | |
348 | */ | |
349 | class subtractive_rng | |
350 | : public unary_function<unsigned int, unsigned int> | |
01b0d4b8 | 351 | { |
4a787fa8 PC |
352 | private: |
353 | unsigned int _M_table[55]; | |
354 | size_t _M_index1; | |
355 | size_t _M_index2; | |
356 | ||
357 | public: | |
358 | /// Returns a number less than the argument. | |
359 | unsigned int | |
360 | operator()(unsigned int __limit) | |
361 | { | |
362 | _M_index1 = (_M_index1 + 1) % 55; | |
363 | _M_index2 = (_M_index2 + 1) % 55; | |
364 | _M_table[_M_index1] = _M_table[_M_index1] - _M_table[_M_index2]; | |
365 | return _M_table[_M_index1] % __limit; | |
01b0d4b8 | 366 | } |
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367 | |
368 | void | |
369 | _M_initialize(unsigned int __seed) | |
370 | { | |
371 | unsigned int __k = 1; | |
372 | _M_table[54] = __seed; | |
373 | size_t __i; | |
374 | for (__i = 0; __i < 54; __i++) | |
375 | { | |
376 | size_t __ii = (21 * (__i + 1) % 55) - 1; | |
377 | _M_table[__ii] = __k; | |
378 | __k = __seed - __k; | |
379 | __seed = _M_table[__ii]; | |
380 | } | |
381 | for (int __loop = 0; __loop < 4; __loop++) | |
382 | { | |
383 | for (__i = 0; __i < 55; __i++) | |
01b0d4b8 | 384 | _M_table[__i] = _M_table[__i] - _M_table[(1 + __i + 30) % 55]; |
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385 | } |
386 | _M_index1 = 0; | |
387 | _M_index2 = 31; | |
01b0d4b8 | 388 | } |
01b0d4b8 | 389 | |
4a787fa8 PC |
390 | /// Ctor allowing you to initialize the seed. |
391 | subtractive_rng(unsigned int __seed) | |
392 | { _M_initialize(__seed); } | |
393 | ||
394 | /// Default ctor; initializes its state with some number you don't see. | |
395 | subtractive_rng() | |
396 | { _M_initialize(161803398u); } | |
397 | }; | |
398 | ||
399 | // Mem_fun adaptor helper functions mem_fun1 and mem_fun1_ref, | |
400 | // provided for backward compatibility, they are no longer part of | |
401 | // the C++ standard. | |
402 | ||
403 | template <class _Ret, class _Tp, class _Arg> | |
404 | inline mem_fun1_t<_Ret, _Tp, _Arg> | |
405 | mem_fun1(_Ret (_Tp::*__f)(_Arg)) | |
406 | { return mem_fun1_t<_Ret, _Tp, _Arg>(__f); } | |
407 | ||
408 | template <class _Ret, class _Tp, class _Arg> | |
409 | inline const_mem_fun1_t<_Ret, _Tp, _Arg> | |
410 | mem_fun1(_Ret (_Tp::*__f)(_Arg) const) | |
411 | { return const_mem_fun1_t<_Ret, _Tp, _Arg>(__f); } | |
412 | ||
413 | template <class _Ret, class _Tp, class _Arg> | |
414 | inline mem_fun1_ref_t<_Ret, _Tp, _Arg> | |
415 | mem_fun1_ref(_Ret (_Tp::*__f)(_Arg)) | |
416 | { return mem_fun1_ref_t<_Ret, _Tp, _Arg>(__f); } | |
417 | ||
418 | template <class _Ret, class _Tp, class _Arg> | |
419 | inline const_mem_fun1_ref_t<_Ret, _Tp, _Arg> | |
420 | mem_fun1_ref(_Ret (_Tp::*__f)(_Arg) const) | |
421 | { return const_mem_fun1_ref_t<_Ret, _Tp, _Arg>(__f); } | |
3cbc7af0 | 422 | |
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423 | _GLIBCXX_END_NAMESPACE_VERSION |
424 | } // namespace | |
3cbc7af0 | 425 | |
fa30fe72 | 426 | #endif |
01b0d4b8 | 427 |