2 /* Do not edit! -- generated file */
3 #ifndef _SIGC_FUNCTORS_FUNCTOR_TRAIT_H_
4 #define _SIGC_FUNCTORS_FUNCTOR_TRAIT_H_
5 #include <sigc++/type_traits.h>
10 //TODO: When we can break ABI, replace nil by something else, such as sigc_nil.
11 // nil is a keyword in Objective C++. When gcc is used for compiling Objective C++
12 // programs, nil is defined as a preprocessor macro.
13 // https://bugzilla.gnome.org/show_bug.cgi?id=695235
14 #if defined(nil) && defined(SIGC_PRAGMA_PUSH_POP_MACRO)
15 #define SIGC_NIL_HAS_BEEN_PUSHED 1
16 #pragma push_macro("nil")
21 * The nil struct type is used as default template argument in the
22 * unnumbered sigc::signal and sigc::slot templates.
27 #ifndef DOXYGEN_SHOULD_SKIP_THIS
33 #ifdef SIGC_NIL_HAS_BEEN_PUSHED
34 #undef SIGC_NIL_HAS_BEEN_PUSHED
35 #pragma pop_macro("nil")
38 /** @defgroup sigcfunctors Functors
39 * Functors are copyable types that define operator()().
41 * Types that define operator()() overloads with different return types are referred to
42 * as multi-type functors. Multi-type functors are only partially supported in libsigc++.
44 * Closures are functors that store all information needed to invoke a callback from operator()().
46 * Adaptors are functors that alter the signature of a functor's operator()().
48 * libsigc++ defines numerous functors, closures and adaptors.
49 * Since libsigc++ is a callback library, most functors are also closures.
50 * The documentation doesn't distinguish between functors and closures.
52 * The basic functor types libsigc++ provides are created with ptr_fun() and mem_fun()
53 * and can be converted into slots implicitly.
54 * The set of adaptors that ships with libsigc++ is documented in the @ref adaptors module.
56 * If you want to mix user-defined and third party functors with libsigc++,
57 * and you want them to be implicitly convertible into slots, libsigc++ must know
58 * the result type of your functors. There are different ways to achieve that.
60 * - Derive your functors from sigc::functor_base and place
61 * <tt>typedef T_return result_type;</tt> in the class definition.
62 * - Use the macro SIGC_FUNCTOR_TRAIT(T_functor,T_return) in namespace sigc.
63 * Multi-type functors are only partly supported.
64 * - For functors not derived from sigc::functor_base, and not specified with
65 * SIGC_FUNCTOR_TRAIT(), libsigc++ tries to deduce the result type with the
66 * C++11 decltype() specifier. That attempt usually succeeds if the functor
67 * has a single operator()(), but it fails if operator()() is overloaded.
68 * - Use the macro #SIGC_FUNCTORS_HAVE_RESULT_TYPE, if you want libsigc++ to assume
69 * that result_type is defined in all user-defined or third party functors,
70 * whose result type can't be deduced in any other way.
72 * If all these ways to deduce the result type fail, void is assumed.
74 * With libsigc++ versions before 2.6, the macro
75 * #SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE activated the test with
76 * decltype(). That macro is now unneccesary and deprecated.
79 /** A hint to the compiler.
80 * All functors which define @p result_type should publically inherit from this hint.
82 * @ingroup sigcfunctors
84 struct functor_base {};
86 /** Helper class, to determine if decltype() can deduce the result type of a functor.
88 * @ingroup sigcfunctors
90 template <typename T_functor>
91 class can_deduce_result_type_with_decltype
102 static biggerthanint checksize(...);
104 // If decltype(&X_functor::operator()) can't be evaluated, this checksize() overload
105 // is ignored because of the SFINAE rule (Substitution Failure Is Not An Error).
106 template <typename X_functor>
107 static int checksize(X_functor* obj, decltype(&X_functor::operator()) p = nullptr);
110 static const bool value
111 #ifndef DOXYGEN_SHOULD_SKIP_THIS
112 = sizeof(checksize(static_cast<T_functor*>(nullptr))) == sizeof(int)
118 /** Trait that specifies the return type of any type.
119 * Template specializations for functors derived from sigc::functor_base,
120 * for other functors whose result type can be deduced with decltype(),
121 * for function pointers and for class methods are provided.
123 * @tparam T_functor Functor type.
124 * @tparam I_derives_functor_base Whether @p T_functor inherits from sigc::functor_base.
125 * @tparam I_can_use_decltype Whether the result type of @p T_functor can be deduced
128 * @ingroup sigcfunctors
130 template <class T_functor,
131 bool I_derives_functor_base = std::is_base_of<functor_base,T_functor>::value,
132 bool I_can_use_decltype = can_deduce_result_type_with_decltype<T_functor>::value>
135 typedef void result_type;
136 typedef T_functor functor_type;
139 #ifndef DOXYGEN_SHOULD_SKIP_THIS
140 template <class T_functor, bool I_can_use_decltype>
141 struct functor_trait<T_functor, true, I_can_use_decltype>
143 typedef typename T_functor::result_type result_type;
144 typedef T_functor functor_type;
147 template <typename T_functor>
148 struct functor_trait<T_functor, false, true>
150 typedef typename functor_trait<decltype(&T_functor::operator()), false, false>::result_type result_type;
151 typedef T_functor functor_type;
153 #endif // DOXYGEN_SHOULD_SKIP_THIS
155 /** Helper macro, if you want to mix user-defined and third party functors with libsigc++.
157 * If you want to mix functors not derived from sigc::functor_base with libsigc++, and
158 * these functors define @p result_type, use this macro inside namespace sigc like so:
160 * namespace sigc { SIGC_FUNCTORS_HAVE_RESULT_TYPE }
163 * @ingroup sigcfunctors
165 #define SIGC_FUNCTORS_HAVE_RESULT_TYPE \
166 template <class T_functor> \
167 struct functor_trait<T_functor, false, false> \
169 typedef typename T_functor::result_type result_type; \
170 typedef T_functor functor_type; \
173 /** Helper macro, if you want to mix user-defined and third party functors with libsigc++.
175 * If you want to mix functors not derived from sigc::functor_base with libsigc++, and
176 * these functors don't define @p result_type, use this macro inside namespace sigc
177 * to expose the return type of the functors like so:
180 * SIGC_FUNCTOR_TRAIT(first_functor_type, return_type_of_first_functor_type)
181 * SIGC_FUNCTOR_TRAIT(second_functor_type, return_type_of_second_functor_type)
186 * @ingroup sigcfunctors
188 #define SIGC_FUNCTOR_TRAIT(T_functor,T_return) \
190 struct functor_trait<T_functor, false, false> \
192 typedef T_return result_type; \
193 typedef T_functor functor_type; \
196 struct functor_trait<T_functor, false, true> \
198 typedef T_return result_type; \
199 typedef T_functor functor_type; \
202 #ifndef SIGCXX_DISABLE_DEPRECATED
203 /** Helper macro, if you want to mix user-defined and third party functors with libsigc++.
205 * If you want to mix functors not derived from sigc::functor_base with libsigc++,
206 * and your compiler can deduce the result type of the functor with the C++11
207 * keyword <tt>decltype</tt>, use this macro inside namespace sigc like so:
210 * SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
214 * Functors with overloaded operator()() are not supported.
218 * @deprecated This macro does nothing. The test it activated in libsigc++
219 * versions before 2.6, is now unconditionally activated.
221 * @ingroup sigcfunctors
223 #define SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE // Empty
224 #endif // SIGCXX_DISABLE_DEPRECATED
226 #ifndef DOXYGEN_SHOULD_SKIP_THIS
227 // detect the return type and the functor version of non-functor types.
228 template <class T_return> class pointer_functor0;
229 template <class T_return>
230 struct functor_trait<T_return (*)(), false, false>
232 typedef T_return result_type;
233 typedef pointer_functor0<T_return> functor_type;
236 template <class T_arg1, class T_return> class pointer_functor1;
237 template <class T_arg1, class T_return>
238 struct functor_trait<T_return (*)(T_arg1), false, false>
240 typedef T_return result_type;
241 typedef pointer_functor1<T_arg1, T_return> functor_type;
244 template <class T_arg1, class T_arg2, class T_return> class pointer_functor2;
245 template <class T_arg1, class T_arg2, class T_return>
246 struct functor_trait<T_return (*)(T_arg1, T_arg2), false, false>
248 typedef T_return result_type;
249 typedef pointer_functor2<T_arg1, T_arg2, T_return> functor_type;
252 template <class T_arg1, class T_arg2, class T_arg3, class T_return> class pointer_functor3;
253 template <class T_arg1, class T_arg2, class T_arg3, class T_return>
254 struct functor_trait<T_return (*)(T_arg1, T_arg2, T_arg3), false, false>
256 typedef T_return result_type;
257 typedef pointer_functor3<T_arg1, T_arg2, T_arg3, T_return> functor_type;
260 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_return> class pointer_functor4;
261 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_return>
262 struct functor_trait<T_return (*)(T_arg1, T_arg2, T_arg3, T_arg4), false, false>
264 typedef T_return result_type;
265 typedef pointer_functor4<T_arg1, T_arg2, T_arg3, T_arg4, T_return> functor_type;
268 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_return> class pointer_functor5;
269 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_return>
270 struct functor_trait<T_return (*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5), false, false>
272 typedef T_return result_type;
273 typedef pointer_functor5<T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_return> functor_type;
276 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_return> class pointer_functor6;
277 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_return>
278 struct functor_trait<T_return (*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6), false, false>
280 typedef T_return result_type;
281 typedef pointer_functor6<T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_return> functor_type;
284 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_arg7, class T_return> class pointer_functor7;
285 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_arg7, class T_return>
286 struct functor_trait<T_return (*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7), false, false>
288 typedef T_return result_type;
289 typedef pointer_functor7<T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7, T_return> functor_type;
293 template <class T_return, class T_obj> class mem_functor0;
294 template <class T_return, class T_obj> class const_mem_functor0;
295 template <class T_return, class T_obj>
296 struct functor_trait<T_return (T_obj::*)(), false, false>
298 typedef T_return result_type;
299 typedef mem_functor0<T_return, T_obj> functor_type;
301 template <class T_return, class T_obj>
302 struct functor_trait<T_return (T_obj::*)() const, false, false>
304 typedef T_return result_type;
305 typedef const_mem_functor0<T_return, T_obj> functor_type;
308 template <class T_return, class T_obj, class T_arg1> class mem_functor1;
309 template <class T_return, class T_obj, class T_arg1> class const_mem_functor1;
310 template <class T_arg1, class T_return, class T_obj>
311 struct functor_trait<T_return (T_obj::*)(T_arg1), false, false>
313 typedef T_return result_type;
314 typedef mem_functor1<T_return, T_obj, T_arg1> functor_type;
316 template <class T_arg1, class T_return, class T_obj>
317 struct functor_trait<T_return (T_obj::*)(T_arg1) const, false, false>
319 typedef T_return result_type;
320 typedef const_mem_functor1<T_return, T_obj, T_arg1> functor_type;
323 template <class T_return, class T_obj, class T_arg1, class T_arg2> class mem_functor2;
324 template <class T_return, class T_obj, class T_arg1, class T_arg2> class const_mem_functor2;
325 template <class T_arg1, class T_arg2, class T_return, class T_obj>
326 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2), false, false>
328 typedef T_return result_type;
329 typedef mem_functor2<T_return, T_obj, T_arg1, T_arg2> functor_type;
331 template <class T_arg1, class T_arg2, class T_return, class T_obj>
332 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2) const, false, false>
334 typedef T_return result_type;
335 typedef const_mem_functor2<T_return, T_obj, T_arg1, T_arg2> functor_type;
338 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3> class mem_functor3;
339 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3> class const_mem_functor3;
340 template <class T_arg1, class T_arg2, class T_arg3, class T_return, class T_obj>
341 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3), false, false>
343 typedef T_return result_type;
344 typedef mem_functor3<T_return, T_obj, T_arg1, T_arg2, T_arg3> functor_type;
346 template <class T_arg1, class T_arg2, class T_arg3, class T_return, class T_obj>
347 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3) const, false, false>
349 typedef T_return result_type;
350 typedef const_mem_functor3<T_return, T_obj, T_arg1, T_arg2, T_arg3> functor_type;
353 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4> class mem_functor4;
354 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4> class const_mem_functor4;
355 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_return, class T_obj>
356 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4), false, false>
358 typedef T_return result_type;
359 typedef mem_functor4<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4> functor_type;
361 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_return, class T_obj>
362 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4) const, false, false>
364 typedef T_return result_type;
365 typedef const_mem_functor4<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4> functor_type;
368 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5> class mem_functor5;
369 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5> class const_mem_functor5;
370 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_return, class T_obj>
371 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5), false, false>
373 typedef T_return result_type;
374 typedef mem_functor5<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5> functor_type;
376 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_return, class T_obj>
377 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5) const, false, false>
379 typedef T_return result_type;
380 typedef const_mem_functor5<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5> functor_type;
383 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6> class mem_functor6;
384 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6> class const_mem_functor6;
385 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_return, class T_obj>
386 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6), false, false>
388 typedef T_return result_type;
389 typedef mem_functor6<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6> functor_type;
391 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_return, class T_obj>
392 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6) const, false, false>
394 typedef T_return result_type;
395 typedef const_mem_functor6<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6> functor_type;
398 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_arg7> class mem_functor7;
399 template <class T_return, class T_obj, class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_arg7> class const_mem_functor7;
400 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_arg7, class T_return, class T_obj>
401 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7), false, false>
403 typedef T_return result_type;
404 typedef mem_functor7<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7> functor_type;
406 template <class T_arg1, class T_arg2, class T_arg3, class T_arg4, class T_arg5, class T_arg6, class T_arg7, class T_return, class T_obj>
407 struct functor_trait<T_return (T_obj::*)(T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7) const, false, false>
409 typedef T_return result_type;
410 typedef const_mem_functor7<T_return, T_obj, T_arg1, T_arg2, T_arg3, T_arg4, T_arg5, T_arg6, T_arg7> functor_type;
414 #endif // DOXYGEN_SHOULD_SKIP_THIS
416 } /* namespace sigc */
417 #endif /* _SIGC_FUNCTORS_FUNCTOR_TRAIT_H_ */