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source: code/branches/cpp11_v2/src/libraries/core/command/Functor.h @ 10979

Last change on this file since 10979 was 10979, checked in by landauf, 8 years ago

gcc doesn't allow an explicit spezialization of a function-template inside a class-template. but we can use function overloading instead of templates.

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1/*
2 *   ORXONOX - the hottest 3D action shooter ever to exist
3 *                    > www.orxonox.net <
4 *
5 *
6 *   License notice:
7 *
8 *   This program is free software; you can redistribute it and/or
9 *   modify it under the terms of the GNU General Public License
10 *   as published by the Free Software Foundation; either version 2
11 *   of the License, or (at your option) any later version.
12 *
13 *   This program is distributed in the hope that it will be useful,
14 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *   GNU General Public License for more details.
17 *
18 *   You should have received a copy of the GNU General Public License
19 *   along with this program; if not, write to the Free Software
20 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
21 *
22 *   Author:
23 *      Fabian 'x3n' Landau
24 *   Co-authors:
25 *      ...
26 *
27 */
28
29/**
30    @file
31    @ingroup Command FunctorExecutor
32    @brief Definition of orxonox::Functor and its specialized subclasses, as well as the createFunctor() functions.
33
34    @anchor FunctorExample
35
36    Functors can be used to wrap function-pointers. While function-pointers have a very
37    complicated syntax in C++, Functors are always the same and you can call the wrapped
38    function-pointer independently of its parameter with arguments of type MultiType. These
39    arguments are then automatically converted to the right type.
40
41    To create a Functor, the helper function createFunctor() is used. It returns an instance
42    of orxonox::FunctorPtr which is simply a typedef of "std::shared_ptr<Functor>". This
43    means you don't have to delete the Functor after using it, because it is managed
44    by the std::shared_ptr.
45
46    Example:
47    @code
48    int myStaticFunction(int value)                         // Definition of a static function
49    {
50        return (value * 2);                                 // Return the double of the value
51    }
52
53    FunctorPtr functor = createFunctor(&myStaticFunction);  // Create a Functor
54
55    int result = (*functor)(5);                             // Calls the functor with value = 5, result == 10
56
57    int result = (*functor)("7");                           // Calls the functor with a string which is converted to an integer, result == 14
58    @endcode
59
60    Functors can also be used if you work with member-functions. In this case createFunctor()
61    returns an instance of orxonox::FunctorMemberPtr - this allows you to define the object
62    that will be used to call the function.
63
64    Example:
65    @code
66    class MyClass                                                   // Define a class
67    {
68        public:
69            MyClass(const std::string& text)                        // Constructor
70            {
71                this->text_ = text;
72            }
73
74            bool contains(const std::string& word)                  // Function that searches for "word" in "text"
75            {
76                return (this->text_.find(word) != std::string::npos);
77            }
78
79        private:
80            std::string text_;                                      // Member variable
81    };
82
83    MyClass* object = new MyClass("Hello World");                   // Create an object of type MyClass and set its text to "Hello World"
84
85    FunctorPtr functor = createFunctor(&MyClass:contains, object);  // Create a Functor (note the object!)
86
87    bool result = (*functor)("World");                              // result == true
88    bool result = (*functor)("test");                               // result == false
89    @endcode
90
91    Instead of assigning the object directly to the functor when creating it, you can also define
92    it at any later point or when you call the functor. Note however that this works only with
93    orxonox::FunctorMember.
94
95    @code
96    MyClass* object1 = new MyClass("Hello World");                  // Create an object
97    MyClass* object2 = new MyClass("this is a test");               // Create another object
98
99    FunctorMemberPtr functor = createFunctor(&MyClass:contains);    // Create a FunctorMember (note: no object this time)
100
101    bool result = (*functor)("World");                              // result == false and an error: "Error: Can't execute FunctorMember, no object set."
102
103    bool result = (*functor)(object1, "World");                     // result == true
104    bool result = (*functor)(object1, "test");                      // result == false
105    bool result = (*functor)(object2, "test");                      // result == true
106
107    functor->setObject(object1);                                    // Assign an object to the FunctorMember
108
109    bool result = (*functor)("World");                              // result == true (no error this time, because the object was set using setObject())
110    @endcode
111*/
112
113#ifndef _Functor_H__
114#define _Functor_H__
115
116#include "core/CorePrereqs.h"
117
118#include <array>
119#include <typeindex>
120#include <type_traits>
121#include <tuple>
122
123#include "util/Output.h"
124#include "util/MultiType.h"
125#include "core/object/Destroyable.h"
126#include "FunctorPtr.h"
127
128namespace orxonox
129{
130    const unsigned int MAX_FUNCTOR_ARGUMENTS = 5;   ///< The maximum number of parameters of a function that is supported by Functor
131
132    namespace detail
133    {
134        template <class T>
135        inline std::string _typeToString() { return "unknown"; }
136
137        template <> inline std::string _typeToString<void>()               { return "void"; }
138        template <> inline std::string _typeToString<int>()                { return "int"; }
139        template <> inline std::string _typeToString<unsigned int>()       { return "uint"; }
140        template <> inline std::string _typeToString<char>()               { return "char"; }
141        template <> inline std::string _typeToString<unsigned char>()      { return "uchar"; }
142        template <> inline std::string _typeToString<short>()              { return "short"; }
143        template <> inline std::string _typeToString<unsigned short>()     { return "ushort"; }
144        template <> inline std::string _typeToString<long>()               { return "long"; }
145        template <> inline std::string _typeToString<unsigned long>()      { return "ulong"; }
146        template <> inline std::string _typeToString<long long>()          { return "longlong"; }
147        template <> inline std::string _typeToString<unsigned long long>() { return "ulonglong"; }
148        template <> inline std::string _typeToString<float>()              { return "float"; }
149        template <> inline std::string _typeToString<double>()             { return "double"; }
150        template <> inline std::string _typeToString<long double>()        { return "longdouble"; }
151        template <> inline std::string _typeToString<bool>()               { return "bool"; }
152        template <> inline std::string _typeToString<std::string>()        { return "string"; }
153        template <> inline std::string _typeToString<Vector2>()            { return "Vector2"; }
154        template <> inline std::string _typeToString<Vector3>()            { return "Vector3"; }
155        template <> inline std::string _typeToString<Quaternion>()         { return "Quaternion"; }
156        template <> inline std::string _typeToString<ColourValue>()        { return "ColourValue"; }
157        template <> inline std::string _typeToString<Radian>()             { return "Radian"; }
158        template <> inline std::string _typeToString<Degree>()             { return "Degree"; }
159    }
160
161    /// Returns the name of type @a T as string.
162    template <class T>
163    inline std::string typeToString() { return detail::_typeToString<typename Loki::TypeTraits<T>::UnqualifiedReferredType>(); }
164
165    /**
166        @brief The Functor classes are used to wrap function pointers.
167
168        Function-pointers in C++ have a pretty complicated syntax and you can't store
169        and call them unless you know the exact type. A Functor can be used to wrap
170        a function-pointer and to store it independent of its type. You can also call
171        it independently of its parameters by passing the arguments as MultiType. They
172        are converted automatically to the right type.
173
174        Functor is a pure virtual base class.
175
176        @see See @ref FunctorExample "Functor.h" for some examples.
177    */
178    class _CoreExport Functor
179    {
180        public:
181            struct Type
182            {
183                /// Defines the type of a function (static or member)
184                enum Enum
185                {
186                    Static,
187                    Member
188                };
189            };
190
191        public:
192            virtual ~Functor() {}
193
194            /// Calls the function-pointer with up to five arguments. In case of a member-function, the assigned object-pointer is used to call the function. @return Returns the return-value of the function (if any; MultiType::Null otherwise)
195            virtual MultiType operator()(const MultiType& param1 = MultiType::Null, const MultiType& param2 = MultiType::Null, const MultiType& param3 = MultiType::Null, const MultiType& param4 = MultiType::Null, const MultiType& param5 = MultiType::Null) = 0;
196
197            /// Creates a new instance of Functor with the same values like this (used instead of a copy-constructor)
198            virtual FunctorPtr clone() = 0;
199
200            /// Returns the type of the function: static or member.
201            virtual Type::Enum getType() const = 0;
202            /// Returns the number of parameters of the function.
203            virtual unsigned int getParamCount() const = 0;
204            /// Returns true if the function has a return-value.
205            virtual bool hasReturnvalue() const = 0;
206
207            /// Returns the type-name of the parameter with given index (the first parameter has index 0).
208            virtual std::string getTypenameParam(unsigned int index) const = 0;
209            /// Returns the type-name of the return-value.
210            virtual std::string getTypenameReturnvalue() const = 0;
211
212            /// Converts a given argument to the type of the parameter with given index (the first parameter has index 0).
213            virtual void evaluateArgument(unsigned int index, MultiType& argument) const = 0;
214
215            /// Assigns an object-pointer to the functor which is used to execute a member-function.
216            virtual void setRawObjectPointer(void* object) = 0;
217            /// Returns the object-pointer.
218            virtual void* getRawObjectPointer() const = 0;
219
220            /// Enables or disables the safe mode which causes the functor to change the object pointer to nullptr if the object is deleted (only member functors).
221            virtual void setSafeMode(bool bSafeMode) = 0;
222
223            /// Returns the full identifier of the function-pointer which is defined as typeid(@a F), where @a F is the type of the stored function-pointer. Used to compare functors.
224            virtual const std::type_index getFullIdentifier() const = 0;
225            /// Returns an identifier of the header of the function (doesn't include the function's class). Used to compare functors.
226            virtual const std::type_index getHeaderIdentifier() const = 0;
227            /// Returns an identifier of the header of the function (doesn't include the function's class), but regards only the first @a params parameters. Used to compare functions if an Executor provides default-values for the other parameters.
228            virtual const std::type_index getHeaderIdentifier(unsigned int params) const = 0;
229    };
230
231    /**
232        @brief FunctorMember is a child class of Functor and expands it with an object-pointer, that
233        is used for member-functions, as well as an overloaded execution operator.
234
235        @param O The type of the function's class (or void if it's a static function)
236
237        Note that FunctorMember is also used for static functions, but with T = void. FunctorStatic
238        is a typedef of FunctorMember<void>. The void* object-pointer is ignored in this case.
239
240        @see See @ref FunctorExample "Functor.h" for some examples.
241    */
242    template <class O>
243    class FunctorMember : public Functor, public DestructionListener
244    {
245        public:
246            /// Constructor: Stores the object-pointer.
247            FunctorMember(O* object = nullptr) : object_(object), bSafeMode_(false) {}
248            virtual ~FunctorMember() { if (this->bSafeMode_) { this->unregisterObject(this->object_); } }
249
250            /// Calls the function-pointer with up to five arguments and an object. In case of a static-function, the object can be nullptr. @return Returns the return-value of the function (if any; MultiType::Null otherwise)
251            virtual MultiType operator()(O* object, const MultiType& param1 = MultiType::Null, const MultiType& param2 = MultiType::Null, const MultiType& param3 = MultiType::Null, const MultiType& param4 = MultiType::Null, const MultiType& param5 = MultiType::Null) = 0;
252
253            // see Functor::operator()()
254            virtual MultiType operator()(const MultiType& param1 = MultiType::Null, const MultiType& param2 = MultiType::Null, const MultiType& param3 = MultiType::Null, const MultiType& param4 = MultiType::Null, const MultiType& param5 = MultiType::Null) override
255            {
256                // call the function if an object was assigned
257                if (this->object_)
258                    return (*this)(this->object_, param1, param2, param3, param4, param5);
259                else
260                {
261                    orxout(internal_error) << "Can't execute FunctorMember, no object set." << endl;
262                    return MultiType::Null;
263                }
264            }
265
266            // see Functor::getType()
267            virtual inline Functor::Type::Enum getType() const override
268                { return Functor::Type::Member; }
269
270            /// Assigns an object-pointer to the functor which is used to execute a member-function.
271            inline void setObject(O* object)
272            {
273                if (this->bSafeMode_ && object != this->object_)
274                {
275                    this->unregisterObject(this->object_);
276                    this->registerObject(object);
277                }
278                this->object_ = object;
279            }
280            /// Returns the object-pointer.
281            inline O* getObject() const
282                { return this->object_; }
283
284            // see Functor::setRawObjectPointer()
285            virtual inline void setRawObjectPointer(void* object) override
286                { this->setObject((O*)object); }
287            // see Functor::getRawObjectPointer()
288            virtual inline void* getRawObjectPointer() const override
289                { return this->object_; }
290
291            // see Functor::setSafeMode()
292            virtual inline void setSafeMode(bool bSafeMode) override
293            {
294                if (bSafeMode == this->bSafeMode_)
295                    return;
296
297                this->bSafeMode_ = bSafeMode;
298
299                if (bSafeMode)
300                    this->registerObject(this->object_);
301                else
302                    this->unregisterObject(this->object_);
303            }
304
305        protected:
306            /// Casts the object and registers as destruction listener if the object is a Destroyable.
307            inline void registerObject(Destroyable* object)
308                { this->registerAsDestructionListener(object); }
309
310            inline void registerObject(void* object) {}
311
312            /// Casts the object and unregisters as destruction listener if the object is a Destroyable.
313            inline void unregisterObject(Destroyable* object)
314                { this->unregisterAsDestructionListener(object); }
315
316            inline void unregisterObject(void* object) {}
317
318            /// Will be called by Destroyable::~Destroyable() if the stored object is a Destroyable and deleted and the Functor is in safe mode.
319            virtual inline void objectDeleted() override
320                { this->object_ = nullptr; }
321
322            O* object_;     ///< The stored object-pointer, used to execute a member-function (or nullptr for static functions)
323            bool bSafeMode_; ///< If true, the functor is in safe mode and registers itself as listener at the object and changes the pointer to nullptr if the object is deleted
324    };
325
326    /// Specialization of FunctorMember with @a T = void.
327    template <>
328    class FunctorMember<void> : public Functor
329    {
330        public:
331            /// Constructor: Stores the object-pointer.
332            FunctorMember(void* object = nullptr) {}
333
334            /// Calls the function-pointer with up to five arguments and an object. In case of a static-function, the object can be nullptr. @return Returns the return-value of the function (if any; MultiType::Null otherwise)
335            virtual MultiType operator()(void* object, const MultiType& param1 = MultiType::Null, const MultiType& param2 = MultiType::Null, const MultiType& param3 = MultiType::Null, const MultiType& param4 = MultiType::Null, const MultiType& param5 = MultiType::Null) = 0;
336
337            // see Functor::operator()()
338            virtual MultiType operator()(const MultiType& param1 = MultiType::Null, const MultiType& param2 = MultiType::Null, const MultiType& param3 = MultiType::Null, const MultiType& param4 = MultiType::Null, const MultiType& param5 = MultiType::Null) override
339            {
340                return (*this)((void*)nullptr, param1, param2, param3, param4, param5);
341            }
342
343            // see Functor::getType()
344            virtual inline Functor::Type::Enum getType() const override
345                { return Functor::Type::Static; }
346
347            // see Functor::setRawObjectPointer()
348            virtual inline void setRawObjectPointer(void*) override
349                { orxout(internal_warning) << "Can't assign an object pointer to a static functor" << endl; }
350            // see Functor::getRawObjectPointer()
351            virtual inline void* getRawObjectPointer() const override
352                { return nullptr; }
353
354            // see Functor::setSafeMode()
355            virtual inline void setSafeMode(bool) override {}
356    };
357
358    /// FunctorStatic is just a typedef of FunctorMember with @a T = void.
359    typedef FunctorMember<void> FunctorStatic;
360
361    /**
362        @brief FunctorPointer is a child class of FunctorMember and expands it with a function-pointer.
363        @param F The type of the function-pointer
364        @param O The type of the function's class (or void if it's a static function)
365
366        The template FunctorPointer has an additional template parameter that defines the type
367        of the function-pointer. This can be handy if you want to get or set the function-pointer.
368        You can then use a static_cast to cast a Functor to FunctorPointer if you know the type
369        of the function-pointer.
370
371        However FunctorPointer is not aware of the types of the different parameters or the
372        return value.
373    */
374    template <class F, class O = void>
375    class FunctorPointer : public FunctorMember<O>
376    {
377        public:
378            /// Constructor: Initializes the base class and stores the function-pointer.
379            FunctorPointer(F functionPointer, O* object = nullptr) : FunctorMember<O>(object), functionPointer_(functionPointer) {}
380
381            /// Changes the function-pointer.
382            inline void setFunction(F functionPointer)
383                { this->functionPointer_ = functionPointer; }
384            /// Returns the function-pointer.
385            inline F getFunction() const
386                { return this->functionPointer_; }
387
388            // see Functor::getFullIdentifier()
389            const std::type_index getFullIdentifier() const
390                { return typeid(F); }
391
392        protected:
393            F functionPointer_;     ///< The stored function-pointer
394    };
395
396    namespace detail
397    {
398        // Helper class to get the type of the function pointer with the given class, parameters, return-value, and constness
399        template <class R, class O, bool isconst, class... Params> struct FunctionPointer                                   { typedef R (O::*Type)(Params...); };
400        template <class R, class O, class... Params>               struct FunctionPointer<R, O, true, Params...>            { typedef R (O::*Type)(Params...) const; };
401        template <class R, class... Params>                        struct FunctionPointer<R, void, false, Params...>        { typedef R (*Type)(Params...); };
402
403        // Helper class, used to call a function-pointer with a given object and parameters and to return its return-value (if available)
404        template <class R, class O, bool isconst, class... Params>         struct FunctorCaller                                        { static inline MultiType call(typename detail::FunctionPointer<R, O, isconst, Params...>::Type functionPointer, O* object, const Params&... parameters)    { return (object->*functionPointer)(parameters...); } };
405        template <class O, bool isconst, class... Params>                  struct FunctorCaller<void, O, isconst, Params...>           { static inline MultiType call(typename detail::FunctionPointer<void, O, isconst, Params...>::Type functionPointer, O* object, const Params&... parameters) { (object->*functionPointer)(parameters...); return MultiType::Null; } };
406        template <class R, bool isconst, class... Params>                  struct FunctorCaller<R, void, isconst, Params...>           { static inline MultiType call(typename detail::FunctionPointer<R, void, isconst, Params...>::Type functionPointer, void*, const Params&... parameters)     { return (*functionPointer)(parameters...); } };
407        template <bool isconst, class... Params>                           struct FunctorCaller<void, void, isconst, Params...>        { static inline MultiType call(typename detail::FunctionPointer<void, void, isconst, Params...>::Type functionPointer, void*, const Params&... parameters)  { (*functionPointer)(parameters...); return MultiType::Null; } };
408
409        // Helper class, used to identify the header of a function-pointer (independent of its class)
410        template <class R, class... Params>
411        struct FunctorHeaderIdentifier
412        {};
413
414        // Helper class to determine if a function has a returnvalue
415        template <class T>
416        struct FunctorHasReturnvalue
417        { enum { result = true }; };
418        template <>
419        struct FunctorHasReturnvalue<void>
420        { enum { result = false }; };
421
422        //Barebones implementation of (make_)index_sequence for C++11
423        template <std::size_t...> struct index_sequence {};
424
425        template <std::size_t N, std::size_t... Is>
426        struct make_index_sequence : make_index_sequence<N - 1, N - 1, Is...> {};
427
428        template <std::size_t... Is>
429        struct make_index_sequence<0u, Is...> : index_sequence<Is...> {};
430
431        //Helper structs to deduce the first N types of a parameter pack
432        template<class... Types> struct type_list {};
433
434        template <class T1, class... AllTypes>
435        struct make_type_list_helper
436        {
437            template <std::size_t N, class... Types>
438            struct make_type_list_impl : make_type_list_helper<AllTypes...>::template make_type_list_impl<N - 1, Types..., T1> {};
439
440            template <class... Types>
441            struct make_type_list_impl<1u, Types...> : type_list<Types..., T1> {};
442        };
443
444        template <std::size_t N, class... Types>
445        struct make_type_list : make_type_list_helper<Types...>::template make_type_list_impl<N> {};
446
447        template <class... Types>
448        struct make_type_list<0u, Types...> : type_list<> {};
449    }
450
451    /**
452        @brief FunctorTemplate is a child class of FunctorPointer and implements all functions
453        that need to know the exact types of the parameters, return-value, and class.
454
455        @param R The type of the return-value of the function
456        @param O The class of the function
457        @param isconst True if the function is a const member-function
458        @param Params The types of the parameters
459
460        This template has many parameters and is usually not used directly. It is created by
461        createFunctor(), but only the base-classes Functor, FunctorMember, and FunctorPointer
462        are used directly. It implements all the virtual functions that are declared by its
463        base classes.
464
465        All template arguments can be void.
466    */
467    template <class R, class O, bool isconst, class... Params>
468    class FunctorTemplate : public FunctorPointer<typename detail::FunctionPointer<R, O, isconst, Params...>::Type, O>
469    {
470        static_assert(sizeof...(Params) <= 5, "Only up to 5 parameters are supported");
471
472        public:
473            /// Constructor: Initializes the base class.
474            FunctorTemplate(typename detail::FunctionPointer<R, O, isconst, Params...>::Type functionPointer, O* object = nullptr) : FunctorPointer<typename detail::FunctionPointer<R, O, isconst, Params...>::Type, O>(functionPointer, object) {}
475
476            // see FunctorMember::operator()()
477            virtual MultiType operator()(O* object, const MultiType& param1 = MultiType::Null, const MultiType& param2 = MultiType::Null, const MultiType& param3 = MultiType::Null, const MultiType& param4 = MultiType::Null, const MultiType& param5 = MultiType::Null) override
478            {
479                auto multis = std::make_tuple(param1, param2, param3, param4, param5);
480                return callHelper(object, multis, detail::make_index_sequence<sizeof...(Params)>{});
481            }
482
483            // see Functor::clone()
484            virtual FunctorPtr clone() override
485            {
486                return std::make_shared<FunctorTemplate>(*this);
487            }
488
489            // see Functor::evaluateArgument()
490            virtual void evaluateArgument(unsigned int index, MultiType& argument) const override
491            {
492                static const std::array<std::function<bool(MultiType&)>, sizeof...(Params)> funcs = {&MultiType::convert<Params>...};
493                if (index < funcs.size())
494                {
495                    funcs[index](argument);
496                }
497            }
498
499            // see Functor::getParamCount()
500            virtual unsigned int getParamCount() const override
501            {
502                return sizeof...(Params);
503            }
504
505            // see Functor::hasReturnvalue()
506            virtual bool hasReturnvalue() const override
507            {
508                return detail::FunctorHasReturnvalue<R>::result;
509            }
510
511            // see Functor::getTypenameParam()
512            virtual std::string getTypenameParam(unsigned int index) const override
513            {
514                static const std::array<std::string, sizeof...(Params)> names = { typeToString<Params>()... };
515                if (index >= names.size())
516                {
517                    return "";
518                }
519                return names[index];
520            }
521
522            // see Functor::getTypenameReturnvalue()
523            virtual std::string getTypenameReturnvalue() const override
524            {
525                return typeToString<R>();
526            }
527
528            // see Functor::getHeaderIdentifier()
529            virtual const std::type_index getHeaderIdentifier() const override
530            {
531                return typeid(detail::FunctorHeaderIdentifier<R, Params...>);
532            }
533
534            // see Functor::getHeaderIdentifier(unsigned int)
535            virtual const std::type_index getHeaderIdentifier(unsigned int params) const override
536            {
537                //+1 because e.g. for two parameters, we want typeids for zero, one, or two parameters
538                return getHeaderIdentifierHelper(params, detail::make_index_sequence<sizeof...(Params) + 1>{});
539            }
540
541    private:
542
543            /// Helper function that extracts index numbers of parameters from a tuple. Needed to call the function pointer with the correct amount of arguments.
544            template<typename Tup, std::size_t... index>
545            MultiType callHelper(O* object, Tup&& tup, detail::index_sequence<index...>)
546            {
547                return detail::FunctorCaller<R, O, isconst, Params...>::call(this->functionPointer_, object, std::get<index>(std::forward<Tup>(tup))...);
548            }
549
550            /// Helper function to extract all identifiers of the function pointer using a deduced index sequence
551            template<std::size_t... index>
552            const std::type_index& getHeaderIdentifierHelper(unsigned int params, detail::index_sequence<index...>) const
553            {
554                static const std::array<const std::type_index, sizeof...(index)> typeinfos = { getTypelistIdentifier(detail::make_type_list<index, Params...>{})... };
555                if (params >= typeinfos.size())
556                {
557                    return typeinfos.back();
558                }
559                return typeinfos[params];
560            }
561
562            ///Helper function that deduces a parameter pack of types and returns the corresponding identifier
563            template<class... Types>
564            const std::type_index getTypelistIdentifier(detail::type_list<Types...>) const
565            {
566                return typeid(detail::FunctorHeaderIdentifier<R, Types...>);
567            }
568    };
569
570
571    /**
572    @brief FunctorCallable is a child class of FunctorTemplate. It stores a callable
573    object (e.g. a lambda or a class with operator()) inside and acts like any
574    other functor. Note that it stores a \em copy of the object, not a reference or a pointer.
575    Take care that this functor does not outlive objects that have been captured by reference
576    in a lambda.
577
578    @param F The type of the callable object
579    @param R The type of the return-value of the function
580    @param isconst True if operator() is const
581    @param Params The types of the parameters
582
583    This template can not be used directly when using lambdas - the type of a lambda
584    is not specified. It can only really be used through the base-class Functor.
585    */
586    template <class F, class R, bool isconst, class... Params>
587    class FunctorCallable : public FunctorTemplate<R, F, isconst, Params...>
588    {
589    public:
590        FunctorCallable(const F& obj): FunctorTemplate<R, F, isconst, Params...>(&F::operator(), &obj_)
591            , obj_(obj)
592        {}
593
594    private:
595        F obj_; ///< The callable object
596    };
597
598    namespace detail
599    {
600        //Helper functions to deduce types and constness of operator() and return the correct FunctorCallable
601        template <class F, class R, class... Params> inline FunctorMemberPtr<F> callableHelper(const F& obj, R(F::*func)(Params...) const) { return std::make_shared<FunctorCallable<F, R, true, Params...>>(obj); }
602        template <class F, class R, class... Params> inline FunctorMemberPtr<F> callableHelper(const F& obj, R(F::*func)(Params...)) { return std::make_shared<FunctorCallable<F, R, false, Params...>>(obj); }
603    }
604
605    template <class R, class O, class OO, class... Params> inline FunctorMemberPtr<O> createFunctor(R (O::*functionPointer)(Params...), OO* object) { return std::make_shared<FunctorTemplate<R, O, false, Params...>>(functionPointer, object); }   ///< Creates a new FunctorMember with the given function-pointer and an assigned object
606    template <class R, class O, class OO, class... Params> inline FunctorMemberPtr<O> createFunctor(R (O::*functionPointer)(Params...) const, OO* object) { return std::make_shared<FunctorTemplate<R, O, true, Params...>>(functionPointer, object); }   ///< Creates a new FunctorMember with the given function-pointer and an assigned object
607
608    template <class R, class O, class... Params> inline FunctorMemberPtr<O> createFunctor(R (O::*functionPointer)(Params...)) { return std::make_shared<FunctorTemplate<R, O, false, Params...>>(functionPointer); }   ///< Creates a new FunctorMember with the given function-pointer
609    template <class R, class O, class... Params> inline FunctorMemberPtr<O> createFunctor(R (O::*functionPointer)(Params...) const) { return std::make_shared<FunctorTemplate<R, O, true, Params...>>(functionPointer); }   ///< Creates a new FunctorMember with the given function-pointer
610
611    template <class R, class... Params> inline FunctorStaticPtr createFunctor(R (*functionPointer)(Params...)) { return std::make_shared<FunctorTemplate<R, void, false, Params...>>(functionPointer); }   ///< Creates a new Functor with the given function-pointer
612   
613    template <class F> inline FunctorMemberPtr<F> createFunctor(const F& obj) { return detail::callableHelper(obj, &F::operator()); } ///< Creates a new Functor with a callable object
614}
615
616#endif /* _Functor_H__ */
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