利用C++的模板類比.net的代理文法

用了一段時間.net的代理模式,覺得挺好使.且原來C++代碼中存在大量需要代理的東西,由於沒有近似的東西,都是靠介面實現的,看起來很彆扭.遂想我是不是也能做這麼一個東西.

boost的function不是很熟悉,但基本實現還是明白的.直接用boost::function的話,有點殺雞用牛刀的感覺,因為我僅僅只要一個很小很小的代理文法而已.況且,這麼多年過去了,寫C++代碼越來越沒有激情,正好有這麼個契機,給自己來點激情.

廢話不多說,看代碼(別看注釋,沒有注釋,看不懂就去看boost::function去)

 

vfxdelegate.h

#pragma once</p><p>namespace VFX<br />{<br />template<class _Fn><br />struct Delegate<br />{<br />~Delegate()<br />{<br />delete _M_imp;<br />}</p><p>Delegate();<br />Delegate(_Fn fn);<br />template<class _Cty><br />Delegate(_Cty & obj);<br />template<class _Cty><br />Delegate(_Cty & obj,_Fn fn);</p><p>Delegate & operator = (_Fn fn);<br />template<class _Cty><br />Delegate & operator = (_Cty obj);</p><p>Delegate(const Delegate & rh);<br />Delegate & operator = (const Delegate & rh);</p><p>bool operator == (const Delegate & rh) const;<br />bool operator != (const Delegate & rh) const;</p><p>operator bool () const;<br />void swap(Delegate & rh);<br />};</p><p>template<class _Ty><br />struct MultDelegate<br />{<br />typedef Delegate<_Ty> delegate_type;<br />typedef stl::vector<delegate_type> delegate_vectory;</p><p>MultDelegate & operator += (const delegate_type & dt);<br />MultDelegate & operator -= (const delegate_type & dt);</p><p>void clear();<br />void swap(MultDelegate & rh);<br />private:<br />delegate_vectorym_Events;<br />};</p><p>namespace detail<br />{<br />template<class _Ty><br />struct _DelegateGetType_<br />{<br />typedef _Ty type;<br />};<br />template<class _Ty><br />struct _DelegateGetType_<_Ty*><br />{<br />typedef _Ty type;<br />};<br />template<class _Ty><br />struct _DelegateGetType_<_Ty&><br />{<br />typedef _Ty type;<br />};<br />}<br />}</p><p>#pragma push_macro("TMPARGS")<br />#pragma push_macro("FUNARGS")<br />#pragma push_macro("FUNPARAMS")<br />#pragma push_macro("PARAMSLIST")</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS<br />#define FUNARGS void<br />#define FUNPARAMS void<br />#define PARAMSLIST<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0<br />#define FUNARGS T0<br />#define FUNPARAMS T0 t0<br />#define PARAMSLIST t0<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1<br />#define FUNARGS T0,T1<br />#define FUNPARAMS T0 t0,T1 t1<br />#define PARAMSLIST t0,t1<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2<br />#define FUNARGS T0,T1,T2<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2<br />#define PARAMSLIST t0,t1,t2<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3<br />#define FUNARGS T0,T1,T2,T3<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3<br />#define PARAMSLIST t0,t1,t2,t3<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4<br />#define FUNARGS T0,T1,T2,T3,T4<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4<br />#define PARAMSLIST t0,t1,t2,t3,t4<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4,class T5<br />#define FUNARGS T0,T1,T2,T3,T4,T5<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4,T5 t5<br />#define PARAMSLIST t0,t1,t2,t3,t4,t5<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4,class T5,class T6<br />#define FUNARGS T0,T1,T2,T3,T4,T5,T6<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4,T5 t5,T6 t6<br />#define PARAMSLIST t0,t1,t2,t3,t4,t5,t6<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4,class T5,class T6,class T7<br />#define FUNARGS T0,T1,T2,T3,T4,T5,T6,T7<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4,T5 t5,T6 t6,T7 t7<br />#define PARAMSLIST t0,t1,t2,t3,t4,t5,t6,t7<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4,class T5,class T6,class T7,class T8<br />#define FUNARGS T0,T1,T2,T3,T4,T5,T6,T7,T8<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4,T5 t5,T6 t6,T7 t7,T8 t8<br />#define PARAMSLIST t0,t1,t2,t3,t4,t5,t6,t7,t8<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4,class T5,class T6,class T7,class T8,class T9<br />#define FUNARGS T0,T1,T2,T3,T4,T5,T6,T7,T8,T9<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4,T5 t5,T6 t6,T7 t7,T8 t8,T9 t9<br />#define PARAMSLIST t0,t1,t2,t3,t4,t5,t6,t7,t8,t9<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4,class T5,class T6,class T7,class T8,class T9,class T10<br />#define FUNARGS T0,T1,T2,T3,T4,T5,T6,T7,T8,T9,T10<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4,T5 t5,T6 t6,T7 t7,T8 t8,T9 t9,T10 t10<br />#define PARAMSLIST t0,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10<br />#include "vfxdelegate.inl"</p><p>#undef TMPARGS<br />#undef FUNARGS<br />#undef FUNPARAMS<br />#undef PARAMSLIST<br />#define TMPARGS ,class T0,class T1,class T2,class T3,class T4,class T5,class T6,class T7,class T8,class T9,class T10,class T11<br />#define FUNARGS T0,T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11<br />#define FUNPARAMS T0 t0,T1 t1,T2 t2,T3 t3,T4 t4,T5 t5,T6 t6,T7 t7,T8 t8,T9 t9,T10 t10,T11 t11<br />#define PARAMSLIST t0,t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11<br />#include "vfxdelegate.inl"</p><p>#pragma pop_macro("TMPARGS")<br />#pragma pop_macro("FUNARGS")<br />#pragma pop_macro("FUNPARAMS")<br />#pragma pop_macro("PARAMSLIST")<br />

 

vfxdelegate.inl

namespace VFX<br />{<br />template<class _Result TMPARGS><br />struct Delegate<_Result(FUNARGS)><br />{<br />private:<br />struct Impl<br />{<br />virtual ~Impl(){}<br />virtual _Result Call(FUNPARAMS) = 0;<br />virtual Impl * Clone() const = 0;<br />virtual char Type() const = 0;<br />virtual bool Equip(const Impl * rh) const = 0;<br />};<br />struct FnImpl : Impl<br />{<br />typedef _Result(*fun_type)(FUNARGS);<br />fun_type _M_fn;<br />FnImpl(fun_type fn):_M_fn(fn){}<br />virtual _Result Call(FUNPARAMS)<br />{<br />return _M_fn(PARAMSLIST);<br />}<br />virtual Impl * Clone() const<br />{<br />return new FnImpl(_M_fn);<br />}<br />virtual char Type() const<br />{<br />return 1;<br />}<br />virtual bool Equip(const Impl * rh) const<br />{<br />return _M_fn == ((FnImpl *)rh)->_M_fn;<br />}<br />};<br />template<class _Cty><br />struct MemfnImpl : Impl<br />{<br />typedef _Result(_Cty::*fun_type)(FUNARGS);<br />fun_type _M_fn;<br />_Cty * _M_obj;<br />MemfnImpl(_Cty * obj,fun_type fn):_M_fn(fn),_M_obj(obj){}<br />MemfnImpl(_Cty & obj,fun_type fn):_M_fn(fn),_M_obj(&obj){}<br />virtual _Result Call(FUNPARAMS)<br />{<br />return (_M_obj->*_M_fn)(PARAMSLIST);<br />}<br />virtual Impl * Clone() const<br />{<br />return new MemfnImpl(_M_obj,_M_fn);<br />}<br />virtual char Type() const<br />{<br />return 2;<br />}<br />virtual bool Equip(const Impl * rh) const<br />{<br />return _M_fn == ((MemfnImpl *)rh)->_M_fn && _M_obj == ((MemfnImpl *)rh)->_M_obj;<br />}<br />};<br />template<class _Cty><br />struct ObjfnImpl : Impl<br />{<br />_Cty * _M_obj;<br />ObjfnImpl(_Cty * obj):_M_obj(obj){}<br />ObjfnImpl(_Cty & obj):_M_obj(&obj){}<br />virtual _Result Call(FUNPARAMS)<br />{<br />return _M_obj->operator()(PARAMSLIST);<br />}<br />virtual Impl * Clone() const<br />{<br />return new ObjfnImpl(_M_obj);<br />}<br />virtual char Type() const<br />{<br />return 3;<br />}<br />virtual bool Equip(const Impl * rh) const<br />{<br />return _M_obj == ((MemfnImpl *)rh)->_M_obj;<br />}<br />};</p><p>Impl * _M_imp;</p><p>public:<br />~Delegate()<br />{<br />delete _M_imp;<br />}</p><p>Delegate():_M_imp(0){}<br />Delegate(_Result(*fn)(FUNARGS))<br />:_M_imp(new FnImpl(fn)){}</p><p>template<class _Cty><br />Delegate(_Cty & obj)<br />:_M_imp(new ObjfnImpl<VFX::detail::_DelegateGetType_<_Cty>::type>(obj)){}</p><p>template<class _Cty><br />Delegate(_Cty & obj,_Result(_Cty::*fn)(FUNARGS))<br />:_M_imp(new MemfnImpl<VFX::detail::_DelegateGetType_<_Cty>::type>(obj,fn)){}</p><p>Delegate & operator = (_Result(*fn)(FUNARGS))<br />{<br />delete _M_imp;<br />_M_imp = new FnImpl;<br />}<br />template<class _Cty><br />Delegate & operator = (_Cty obj)<br />{<br />delete _M_imp;<br />_M_imp = new ObjfnImpl<VFX::detail::_DelegateGetType_<_Cty>::type>(obj);<br />}</p><p>Delegate(const Delegate & rh)<br />{<br />if(rh._M_imp != 0)<br />_M_imp = rh._M_imp->Clone();<br />else<br />_M_imp = 0;<br />}<br />Delegate & operator = (const Delegate & rh)<br />{<br />if(this != &rh)<br />{<br />delete _M_imp;<br />if(rh._M_imp != 0)<br />_M_imp = rh._M_imp->Clone();<br />else<br />_M_imp = 0;<br />}<br />return *this;<br />}</p><p>bool operator == (const Delegate & rh) const<br />{<br />if(_M_imp == NULL || rh._M_imp == NULL)<br />return _M_imp == rh._M_imp;<br />return _M_imp->Type() == rh._M_imp->Type() &&<br />_M_imp->Equip(rh._M_imp);<br />}</p><p>bool operator != (const Delegate & rh) const<br />{<br />return !(operator ==(rh));<br />}</p><p>_Result operator()(FUNPARAMS) const<br />{<br />if(_M_imp == NULL)<br />throw std::runtime_error("call null delegate");<br />return _M_imp->Call(PARAMSLIST);<br />}</p><p>operator bool () const<br />{<br />return _M_imp != 0;<br />}</p><p>void swap(Delegate & rh)<br />{<br />Impl * temp = _M_imp;<br />_M_imp = rh._M_imp;<br />rh._M_imp = temp;<br />}<br />};</p><p>template<class _Result TMPARGS><br />struct MultDelegate<_Result(FUNARGS)><br />{<br />typedef Delegate<_Result(FUNARGS)> delegate_type;<br />typedef stl::vector<delegate_type> delegate_vectory;</p><p>void clear()<br />{<br />m_Events.clear();<br />}<br />MultDelegate & operator += (const delegate_type & dt)<br />{<br />for(delegate_vectory::iterator i=m_Events.begin(); i!=m_Events.end(); ++i)<br />{<br />if(*i == dt)<br />return *this;<br />}<br />m_Events.push_back(dt);<br />return *this;<br />}<br />MultDelegate & operator -= (const delegate_type & dt)<br />{<br />for(delegate_vectory::iterator i=m_Events.begin(); i!=m_Events.end(); ++i)<br />{<br />if(*i == dt)<br />{<br />m_Events.erase(i);<br />break;<br />}<br />}<br />return *this;<br />}<br />void operator()(FUNPARAMS) const<br />{<br />for(delegate_vectory::const_iterator i=m_Events.begin(); i!=m_Events.end(); ++i)<br />{<br />if(*i) (*i)(PARAMSLIST);<br />}<br />}</p><p>void swap(MultDelegate & rh)<br />{<br />m_Events.swap(rh.m_Events);<br />}<br />private:<br />delegate_vectorym_Events;<br />};<br />}<br />

 

使用案例:

typedef VFX::Delegate<void(VIPropertyEditAble *)> PropertyGridEvents;</p><p>class PGRID_API CPropertyGridEditor : public CXTPPropertyGrid<br />{<br />DECLARE_DYNAMIC(CPropertyGridEditor)<br />VIPropertyEditAble *m_pObject;</p><p>VFX::MultDelegate<void(VIPropertyEditAble *)> ValueChanged;<br />void NotifyListener_ValueChanged()<br />{<br />this->ValueChanged(m_pObject);<br />}<br />};</p><p>class CMapEditorDoc : public CDocument<br />{<br />void OnGridValueChanged(VIPropertyEditAble * pObject);<br />{<br />if(pObject != NULL)<br />SetModifiedFlag(TRUE);<br />}<br />};</p><p>//CPropertyGridEditorm_wndPropertyGrid;<br />void CMainFrame::InitDocument()<br />{<br />CMapEditorDoc * pDoc = (CMapEditorDoc *)GetActiveDocument();<br />m_wndPropertyGrid.ValueChanged += PropertyGridEvents(*pDoc,&CMapEditorDoc::OnGridValueChanged);<br />}</p><p>

 

註：stl::vector<>是std::vector<,VFX::alloctor>的typedef。因此，你只需要把stl替換成std就可以了