mbed official / mbed-src

mbed library sources

Dependents:   Encrypted my_mbed mbed_forkd lklk ... more

Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

Import librarymbed

The official mbed C/C++ SDK provides the software platform and libraries to build your applications.

api/FunctionPointer.h

Committer:
mbed_official
Date:
22 months ago
Revision:
635:a11c0372f0ba
Parent:
212:34d62c0b2af6

File content as of revision 635:a11c0372f0ba:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2015 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef MBED_FUNCTIONPOINTER_H
#define MBED_FUNCTIONPOINTER_H

#include <string.h>
#include <stdint.h>

namespace mbed {

/* If we had variaditic templates, this wouldn't be a problem, but until C++11 is enabled, we are stuck with multiple classes... */

/** A class for storing and calling a pointer to a static or member function
 */
template <typename R, typename A1>
class FunctionPointerArg1{
public:
    /** Create a FunctionPointer, attaching a static function
     *
     *  @param function The static function to attach (default is none)
     */
    FunctionPointerArg1(R (*function)(A1) = 0) {
        attach(function);
    }

    /** Create a FunctionPointer, attaching a member function
     *
     *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
     *  @param function The address of the member function to attach
     */
    template<typename T>
    FunctionPointerArg1(T *object, R (T::*member)(A1)) {
        attach(object, member);
    }

    /** Attach a static function
     *
     *  @param function The static function to attach (default is none)
     */
    void attach(R (*function)(A1)) {
        _p.function = function;
        _membercaller = 0;
    }

    /** Attach a member function
     *
     *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
     *  @param function The address of the member function to attach
     */
    template<typename T>
    void attach(T *object, R (T::*member)(A1)) {
        _p.object = static_cast<void*>(object);
        *reinterpret_cast<R (T::**)(A1)>(_member) = member;
        _membercaller = &FunctionPointerArg1::membercaller<T>;
    }

    /** Call the attached static or member function
     */
    R call(A1 a) {
        if (_membercaller == 0 && _p.function) {
           return _p.function(a);
        } else if (_membercaller && _p.object) {
           return _membercaller(_p.object, _member, a);
        }
        return (R)0;
    }

    /** Get registered static function
     */
    R(*get_function(A1))() {
        return _membercaller ? (R(*)(A1))0 : (R(*)(A1))_p.function;
    }

#ifdef MBED_OPERATORS
    R operator ()(A1 a) {
        return call(a);
    }
    operator bool(void) const {
        return (_membercaller != NULL ? _p.object : (void*)_p.function) != NULL;
    }
#endif
private:
    template<typename T>
    static R membercaller(void *object, uintptr_t *member, A1 a) {
        T* o = static_cast<T*>(object);
        R (T::**m)(A1) = reinterpret_cast<R (T::**)(A1)>(member);
        return (o->**m)(a);
    }

    union {
        R (*function)(A1); // static function pointer
        void *object;      // object this pointer
    } _p;
    uintptr_t _member[4]; // aligned raw member function pointer storage - converted back by registered _membercaller
    R (*_membercaller)(void*, uintptr_t*, A1); // registered membercaller function to convert back and call _m.member on _object
};

/** A class for storing and calling a pointer to a static or member function (R ()(void))
 */
template <typename R>
class FunctionPointerArg1<R, void>{
public:
    /** Create a FunctionPointer, attaching a static function
     *
     *  @param function The static function to attach (default is none)
     */
    FunctionPointerArg1(R (*function)(void) = 0) {
        attach(function);
    }

    /** Create a FunctionPointer, attaching a member function
     *
     *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
     *  @param function The address of the void member function to attach
     */
    template<typename T>
    FunctionPointerArg1(T *object, R (T::*member)(void)) {
        attach(object, member);
    }

    /** Attach a static function
     *
     *  @param function The void static function to attach (default is none)
     */
    void attach(R (*function)(void)) {
        _p.function = function;
        _membercaller = 0;
    }

    /** Attach a member function
     *
     *  @param object The object pointer to invoke the member function on (i.e. the this pointer)
     *  @param function The address of the void member function to attach
     */
    template<typename T>
    void attach(T *object, R (T::*member)(void)) {
        _p.object = static_cast<void*>(object);
        *reinterpret_cast<R (T::**)(void)>(_member) = member;
        _membercaller = &FunctionPointerArg1::membercaller<T>;
    }

    /** Call the attached static or member function
     */
    R call(){
        if (_membercaller == 0 && _p.function) {
            return _p.function();
        } else if (_membercaller && _p.object) {
            return _membercaller(_p.object, _member);
        }
        return (R)0;
    }

    /** Get registered static function
     */
    R(*get_function())() {
        return _membercaller ? (R(*)())0 : (R(*)())_p.function;
    }

#ifdef MBED_OPERATORS
    R operator ()(void) {
        return call();
    }
    operator bool(void) const {
        return (_membercaller != NULL ? _p.object : (void*)_p.function) != NULL;
    }
#endif

private:
    template<typename T>
    static R membercaller(void *object, uintptr_t *member) {
        T* o = static_cast<T*>(object);
        R (T::**m)(void) = reinterpret_cast<R (T::**)(void)>(member);
        return (o->**m)();
    }

    union {
        R (*function)(void); // static function pointer
        void *object;        // object this pointer
    } _p;
    uintptr_t _member[4]; // aligned raw member function pointer storage - converted back by registered _membercaller
    R (*_membercaller)(void*, uintptr_t*); // registered membercaller function to convert back and call _m.member on _object
};

typedef FunctionPointerArg1<void, void> FunctionPointer;
typedef FunctionPointerArg1<void, int> event_callback_t;

} // namespace mbed

#endif