前两天看程序员杂志
看到关于 C# 中的委托/事件
觉得用起来好像是挺方便的
本人热衷于 C++
想想用 C++ 来模拟似乎也可以
于是就有了下面的代码...
(VC6 不支持偏特化 本人工作环境就是 VC6 痛啊~~~)
没有返回值的函数用 delegate
否则就用 delegate_rt
functor 也一样 functorN/functorN_rt
delegate 的模板参数可以是函数指针(非成员函数)
也可以是 functor
还可以是 delegate
functor 可用 make_functor/make_functor_rt 来生成
要是有偏特化 就可以去掉讨厌的 _rt 了 :(
关于委托 boost里有现成的
不过可能 VC6 里用不了
这些代码旨在个人研究
如果大家发现其中问题 希望能指出
//filename: functor2.h #ifndef _FUNCTOR2_H_ #define _FUNCTOR2_H_ template <typename P1, typename P2> class functor2 { class deleobject { }; typedef void (*func_pt)(P1, P2); typedef void (deleobject::*mem_func_pt)(P1, P2); typedef void (deleobject::*cmem_func_pt)(P1, P2) const; functor_base<deleobject, func_pt, mem_func_pt, cmem_func_pt> base; public: functor2() : base() {} functor2(func_pt pf) : base(pf) {} template<typename T> functor2(const T *pObject, void (T::*fp)(P1, P2)) : base((const deleobject*)(pObject), *((mem_func_pt*)(&fp))) {} template<typename T> functor2(const T &pObject, void (T::*fp)(P1, P2)) : base((const deleobject*)(pObject), *((mem_func_pt*)(&fp))) {} template<typename T> functor2(const T *pObject, void (T::*fp)(P1, P2) const) : base((const deleobject*)(pObject), *((cmem_func_pt*)(&fp))) {} template<typename T> functor2(const T &pObject, void (T::*fp)(P1, P2) const) : base((const deleobject*)(pObject), *((cmem_func_pt*)(&fp))) {} bool operator !=(const functor2& rhs) const { return !(*this == rhs); } bool operator ==(const functor2& rhs) const { return base == rhs.base; } bool operator ==(const void* rhs) const { return base == rhs; } functor2& operator =(const functor2& rhs) { base = rhs.base; return *this; } void operator()(P1 p1, P2 p2) const { if (base.m_pObject == NULL) (*base.m_pf)(p1, p2); else (base.m_pObject->*(base.m_pmf))(p1, p2); } }; template <typename P1, typename P2> inline functor2<P1, P2> make_functor(void (*fp)(P1, P2)) { return functor2<P1, P2>(fp); } template <class T, typename P1, typename P2> inline functor2<P1, P2> make_functor(const T* tp, void (T::*fp)(P1, P2)) { return functor2<P1, P2>(tp, fp); } template <class T, typename P1, typename P2> inline functor2<P1, P2> make_functor(const T* tp, void (T::*fp)(P1, P2) const) { return functor2<P1, P2>(tp, fp); } #endif // #ifndef _FUNCTOR2_H_
//filename: functor2_rt.h #ifndef _FUNCTOR2_RT_H_ #define _FUNCTOR2_RT_H_ template <typename R, typename P1, typename P2> class functor2_rt { class deleobject { }; typedef R (*func_pt)(P1, P2); typedef R (deleobject::*mem_func_pt)(P1, P2); typedef R (deleobject::*cmem_func_pt)(P1, P2) const; functor_base<deleobject, func_pt, mem_func_pt, cmem_func_pt> base; public: functor2_rt() : base() {} functor2_rt(func_pt pf) : base(pf) {} template<typename T> functor2_rt(const T *pObject, R (T::*fp)(P1, P2)) : base((const deleobject*)(pObject), *((mem_func_pt*)(&fp))) {} template<typename T> functor2_rt(const T &pObject, R (T::*fp)(P1, P2)) : base((const deleobject*)(pObject), *((mem_func_pt*)(&fp))) {} template<typename T> functor2_rt(const T *pObject, R (T::*fp)(P1, P2) const) : base((const deleobject*)(pObject), *((cmem_func_pt*)(&fp))) {} template<typename T> functor2_rt(const T &pObject, R (T::*fp)(P1, P2) const) : base((const deleobject*)(pObject), *((cmem_func_pt*)(&fp))) {} bool operator !=(const functor2_rt& rhs) const { return !(*this == rhs); } bool operator ==(const functor2_rt& rhs) const { return base == rhs.base; } bool operator ==(const void* rhs) const { return base == rhs; } functor2_rt& operator =(const functor2_rt& rhs) { base = rhs.base; return *this; } R operator()(P1 p1, P2 p2) const { if (base.m_pObject == NULL) return (*base.m_pf)(p1, p2); else return (base.m_pObject->*(base.m_pmf))(p1, p2); } }; template <typename R, typename P1, typename P2> inline functor2_rt<R, P1, P2> make_functor_rt(R (*fp)(P1, P2)) { return functor2_rt<R, P1, P2>(fp); } template <typename R, class T, typename P1, typename P2> inline functor2_rt<R, P1, P2> make_functor_rt(const T* tp, R (T::*fp)(P1, P2)) { return functor2_rt<R, P1, P2>(tp, fp); } template <typename R, class T, typename P1, typename P2> inline functor2_rt<R, P1, P2> make_functor_rt(const T* tp, R (T::*fp)(P1, P2) const) { return functor2_rt<R, P1, P2>(tp, fp); } #endif // #ifndef _FUNCTOR2_RT_H_
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