为了满足90%以上的应用场合，该代码实现以下目标：
1.支持成员函数和非成员函数绑定。
2.支持多个参数（最多9个），代码中使用#define宏定义了1到9个参数的版本。
3.为了在大规模应用中多次分配function对象造成内存碎片，对new和delete进行重载，方便使用内存池管理内存。
下面贴出代码：
/*
* Author: chzuping
* Email: chzuping@gmail.com
* description: 模拟boost::bind和boost::function
*/
#pragma once;
#ifndef ZWBIND_MALLOC
#define ZWBIND_MALLOC malloc
#endif
#ifndef ZWBIND_FREE
#define ZWBIND_FREE free
#endif
namespace ZwBind
{
class bind_base
{
public:
static void *operator new(size_t size )
{
return ZWBIND_MALLOC(size);
}
static void operator delete( void *ptr)
{
ZWBIND_FREE(ptr);
}
};
template
class bind_base0:public bind_base
{
public:
virtual ret_type callfun() = 0;
ret_type operator()()
{
return callfun();
}
};
template
class bindobj0 : public bind_base0
{
public:
bindobj0(obj_type* pobject, ret_type (obj_type::*pmemfun)())
{
m_pobject = pobject;
m_pmemfun = pmemfun;
}
virtual int callfun()
{
return (m_pobject->*m_pmemfun)();
}
private:
obj_type* m_pobject;
ret_type (obj_type::* m_pmemfun)();
};
template
class bind0 : public bind_base0
{
public:
bind0( ret_type (*pfun)())
{
m_pfun = pfun;
}
virtual ret_type callfun()
{
return m_pfun();
}
private:
ret_type (*m_pfun)();
};
template
bindobj0* bindfun(obj_type* pclass, ret_type (obj_type::*pmemfun)())
{
void *pRet = NULL;
bindobj0* pbind = new bindobj0(pclass, pmemfun);
return pbind;
}
template
bind0* bindfun(ret_type (*pmemfun)())
{
bind0* pbind = new bind0(pmemfun);
return pbind;
}
#define DECLARE_PARAMS(...) __VA_ARGS__
#define DECLARE_TPYE(...) __VA_ARGS__
#define DECLARE_ARGS(...) __VA_ARGS__
#define DECLARE_VAR(...) __VA_ARGS__
#define DECLARE_SIGSLOT(index, ptype,classparam,args,var) \
template\
class bind_base##index\
{\
public:\
virtual ret_type callfun(args) = 0;\
ret_type operator()(args)\
{\
return callfun(var);\
}\
};\
template \
class bindobj##index:public bind_base##index\
{\
public:\
bindobj##index(obj_type* pobject, ret_type (obj_type::*pmemfun)(args))\
{\
m_pobject = pobject;\
m_pmemfun = pmemfun;\
}\
virtual ret_type callfun(args)\
{\
return (m_pobject->*m_pmemfun)(var);\
}\
private:\
obj_type* m_pobject;\
ret_type (obj_type::* m_pmemfun)(args);\
};\
template\
class bind##index : public bind_base##index\
{\
public:\
bind##index(ret_type (*pfun)(args))\
{\
m_pfun = pfun;\
}\
virtual ret_type callfun(args)\
{\
return m_pfun(var);\
}\
private:\
ret_type (*m_pfun)(args);\
};\
template \
bindobj##index* bindfun(obj_type* pclass, ret_type (obj_type::*pmemfun)(args))\
{\
void *pRet = NULL;\
bindobj##index* pbind = new bindobj##index(pclass, pmemfun);\
return pbind;\
}\
template\
bind##index* bindfun(ret_type (*pmemfun)(args))\
{\
bind##index* pbind = new bind##index(pmemfun);\
return pbind;\
}
DECLARE_SIGSLOT(1,DECLARE_PARAMS(arg1_type), DECLARE_TPYE(cl