深入分析:C++模板究竟会使代码膨胀吗

   CWindowImplBaseT():m_pfnSuperWindowProc(::DefWindowProc)
   {}

   staticDWORDGetWndStyle(DWORDdwStyle)
   {
       returnTWinTraits::GetWndStyle(dwStyle);
   }
   staticDWORDGetWndExStyle(DWORDdwExStyle)
   {
       returnTWinTraits::GetWndExStyle(dwExStyle);
   }

   virtualWNDPROCGetWindowProc()
   {
       returnWindowProc;
   }
   staticLRESULTCALLBACKStartWindowProc(HWNDhWnd,UINTuMsg,WPARAMwParam,LPARAMlParam);
   staticLRESULTCALLBACKWindowProc(HWNDhWnd,UINTuMsg,WPARAMwParam,LPARAMlParam);
   HWNDCreate(HWNDhWndParent,_U_RECTrect,LPCTSTRszWindowName,
           DWORDdwStyle,DWORDdwExStyle,_U_MENUorIDMenuOrID,ATOMatom,LPVOIDlpCreateParam=NULL);
   BOOLDestroyWindow()
   {
       ATLASSERT(::IsWindow(m_hWnd));
       return::DestroyWindow(m_hWnd);
   }
   BOOLSubclassWindow(HWNDhWnd);
   HWNDUnsubclassWindow(BOOLbForce=FALSE);

   LRESULTDefWindowProc()
   {
       const_ATL_MSG*pMsg=m_pCurrentMsg;
       LRESULTlRes=0;
       if(pMsg!=NULL)
           lRes=DefWindowProc(pMsg->message,pMsg->wParam,pMsg->lParam);
       returnlRes;
   }

   LRESULTDefWindowProc(UINTuMsg,WPARAMwParam,LPARAMlParam)
   {
#ifdefSTRICT
       return::CallWindowProc(m_pfnSuperWindowProc,m_hWnd,uMsg,wParam,lParam);
#else
       return::CallWindowProc((FARPROC)m_pfnSuperWindowProc,m_hWnd,uMsg,wParam,lParam);
#endif
   }

   virtualvoidOnFinalMessage(HWND/*hWnd*/)
   {
       //overridetodosomething,ifneeded
   }
};

复制代码代码如下:
0:000>xHYTeris!ATL::CWindowImplBaseT<*
0040f170HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::Create(structHWND__*,classATL::_U_RECT,wchar_t*,unsignedlong,unsignedlong,classATL::_U_MENUorID,unsignedshort,void*)
0040ec20HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::GetWndStyle(unsignedlong)
00435970HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::OnFinalMessage(structHWND__*)
004604d0HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::GetWndStyle(unsignedlong)
00434a10HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::~CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>(void)
0040ec60HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::GetWndExStyle(unsignedlong)
00461740HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::WindowProc(structHWND__*,unsignedint,unsignedint,long)
0044c040HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::WindowProc(structHWND__*,unsignedint,unsignedint,long)
004346e0HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::~CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>(void)
0041c440HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>(void)
00435940HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::GetWindowProc(void)
00459580HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::GetWndExStyle(unsignedlong)
00461950HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::Create(structHWND__*,classATL::_U_RECT,wchar_t*,unsignedlong,unsignedlong,classATL::_U_MENUorID,unsignedshort,void*)
004395b0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::StartWindowProc(structHWND__*,unsignedint,unsignedint,long)
00439ea0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::DefWindowProcW(unsignedint,unsignedint,long)
00461620HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::StartWindowProc(structHWND__*,unsignedint,unsignedint,long)
004596e0HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::Create(structHWND__*,classATL::_U_RECT,wchar_t*,unsignedlong,unsignedlong,classATL::_U_MENUorID,unsignedshort,void*)
0041ced0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::WindowProc(structHWND__*,unsignedint,unsignedint,long)
0044c370HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::UnsubclassWindow(int)
00460510HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::GetWndExStyle(unsignedlong)
00457f70HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::WindowProc(structHWND__*,unsignedint,unsignedint,long)
0045f830HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::GetWindowProc(void)
00457820HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>(void)
004374b0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::GetWndExStyle(unsignedlong)
00434ad0HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::~CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>(void)
004595c0HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::StartWindowProc(structHWND__*,unsignedint,unsignedint,long)
004358f0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>(void)
00445920HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::OnFinalMessage(structHWND__*)
00461ad0HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::DefWindowProcW(unsignedint,unsignedint,long)
0041c4c0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::OnFinalMessage(structHWND__*)
00437470HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::GetWndStyle(unsignedlong)
004398e0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::Create(structHWND__*,classATL::_U_RECT,wchar_t*,unsignedlong,unsignedlong,classATL::_U_MENUorID,unsignedshort,void*)
0040ed50HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::StartWindowProc(structHWND__*,unsignedint,unsignedint,long)
004458a0HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>(void)
0045f7e0HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>(void)
0041ad30HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::~CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>(void)
00430550HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::~CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>(void)
0045f860HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::OnFinalMessage(structHWND__*)
004582a0HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::UnsubclassWindow(int)
0041c490HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::GetWindowProc(void)
0044cb50HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::DefWindowProcW(unsignedint,unsignedint,long)
0044c250HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::SubclassWindow(structHWND__*)
004458f0HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::GetWindowProc(void)
00459540HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::GetWndStyle(unsignedlong)
00458180HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::SubclassWindow(structHWND__*)
00457870HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::GetWindowProc(void)
00457910HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::OnFinalMessage(structHWND__*)
0040e990HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::DestroyWindow(void)
004396d0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::WindowProc(structHWND__*,unsignedint,unsignedint,long)
0041d1c0HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::DefWindowProcW(unsignedint,unsignedint,long)
004578a0HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::DefWindowProcW(unsignedint,unsignedint,long)
004d8fc8HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004d8ff4HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::`RTTIBaseClassArray"=<notypeinformation>
004d8fe4HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004d79b4HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::`RTTIBaseClassArray"=<notypeinformation>
004d79a4HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004e2798HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>`RTTITypeDescriptor"=<notypeinformation>
004d819cHYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004d8938HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::`RTTIBaseClassArray"=<notypeinformation>
004d8928HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004d960cHYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::`RTTIBaseClassArray"=<notypeinformation>
004d95fcHYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004e2ee8HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>`RTTITypeDescriptor"=<notypeinformation>
004d81c8HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::`RTTIBaseClassArray"=<notypeinformation>
004d81b8HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004e34a0HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>`RTTITypeDescriptor"=<notypeinformation>
004d95e0HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0>>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004e1f68HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400>>`RTTITypeDescriptor"=<notypeinformation>
004e1688HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>`RTTITypeDescriptor"=<notypeinformation>
004d7988HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004d890cHYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>

可以看到CWindowImplBaseT只与窗口基类和窗口风格相关，数量已经减小很多，CWindowImplBaseT模板类本身函数数量不多，函数代码量大小也不大。

然后再看CWindowImplRoot,

复制代码代码如下:
template<classTBase/*=CWindow*/>
classATL_NO_VTABLECWindowImplRoot:publicTBase,publicCMessageMap
{
public:
   CWndProcThunkm_thunk;
   const_ATL_MSG*m_pCurrentMsg;
   DWORDm_dwState;

   enum{WINSTATE_DESTROYED=0x00000001};

//Constructor/destructor
   CWindowImplRoot():m_pCurrentMsg(NULL),m_dwState(0)
   {}

   virtual~CWindowImplRoot()
   {
#ifdef_DEBUG
       if(m_hWnd!=NULL)   //shouldbeclearedinWindowProc
       {
           ATLTRACE(atlTraceWindowing,0,_T("ERROR-Objectdeletedbeforewindowwasdestroyed\n"));
           ATLASSERT(FALSE);
       }
#endif//_DEBUG
   }

//Currentmessage
   const_ATL_MSG*GetCurrentMessage()const
   {
       returnm_pCurrentMsg;
   }

   //"handled"managementforcrackedhandlers
   BOOLIsMsgHandled()const
   {
       const_ATL_MSG*pMsg=GetCurrentMessage();
       ATLASSERT(pMsg!=NULL);
       ATLASSERT(pMsg->cbSize>=sizeof(_ATL_MSG));
       returnpMsg->bHandled;
   }
   voidSetMsgHandled(BOOLbHandled)
   {
       _ATL_MSG*pMsg=(_ATL_MSG*)GetCurrentMessage();   //overrideconst
       ATLASSERT(pMsg!=NULL);
       ATLASSERT(pMsg->cbSize>=sizeof(_ATL_MSG));
       pMsg->bHandled=bHandled;
   }

//Messageforwardingandreflectionsupport
   LRESULTForwardNotifications(UINTuMsg,WPARAMwParam,LPARAMlParam,BOOL&bHandled);
   LRESULTReflectNotifications(UINTuMsg,WPARAMwParam,LPARAMlParam,BOOL&bHandled);
   staticBOOLDefaultReflectionHandler(HWNDhWnd,UINTuMsg,WPARAMwParam,LPARAMlParam,LRESULT&lResult);
};

复制代码代码如下:
0:000>xHYTeris!ATL::CWindowImplRoot*
004364d0HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>::~CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>(void)
004367d0HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow>>::~CWindowImplRoot<WTL::CEditT<ATL::CWindow>>(void)
00457c30HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>::CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>(void)
00460550HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>(void)
004479d0HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow>>::CWindowImplRoot<WTL::CEditT<ATL::CWindow>>(void)
0041c360HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::~CWindowImplRoot<ATL::CWindow>(void)
00435f40HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>::~CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>(void)
004613f0HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::ForwardNotifications(unsignedint,unsignedint,long,int*)
00438f50HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::ReflectNotifications(unsignedint,unsignedint,long,int*)
0041c8e0HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::CWindowImplRoot<ATL::CWindow>(void)
004e2800HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow>>`RTTITypeDescriptor"=<notypeinformation>
004d897cHYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow>>::`RTTIBaseClassArray"=<notypeinformation>
004d896cHYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004d9640HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004d9650HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>::`RTTIBaseClassArray"=<notypeinformation>
004d8950HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004d9028HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004d9038HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>::`RTTIBaseClassArray"=<notypeinformation>
004e16dcHYTeris!ATL::CWindowImplRoot<ATL::CWindow>`RTTITypeDescriptor"=<notypeinformation>
004e3530HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>`RTTITypeDescriptor"=<notypeinformation>
004d9624HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004d79c8HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004e2f58HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>`RTTITypeDescriptor"=<notypeinformation>
004d79f4HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::`RTTIBaseClassArray"=<notypeinformation>
004d79e4HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004d900cHYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow>>::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>

可以看到CWindowImplRoot只和窗口基类(CWindow)相关，所以相关的符号就更少了。

最后我们再看一下CWindow:

复制代码代码如下:
0:000>xHYTeris!ATL::CWindow::*
004e1000HYTeris!ATL::CWindow::rcDefault=structtagRECT
00442a20HYTeris!ATL::CWindow::DestroyWindow(void)
00425730HYTeris!ATL::CWindow::InvalidateRect(structtagRECT*,int)
00442340HYTeris!ATL::CWindow::CenterWindow(structHWND__*)
00425850HYTeris!ATL::CWindow::UpdateWindow(void)
0041c950HYTeris!ATL::CWindow::CWindow(structHWND__*)
004391e0HYTeris!ATL::CWindow::GetDlgItem(int)
004568a0HYTeris!ATL::CWindow::SetWindowRgn(structHRGN__*,int)
00441d20HYTeris!ATL::CWindow::GetWindowLongW(int)
00444350HYTeris!ATL::CWindow::Create(wchar_t*,structHWND__*,classATL::_U_RECT,wchar_t*,unsignedlong,unsignedlong,classATL::_U_MENUorID,void*)
004391b0HYTeris!ATL::CWindow::operatorHWND__*(void)
00459080HYTeris!ATL::CWindow::EnableWindow(int)
00425140HYTeris!ATL::CWindow::GetClientRect(structtagRECT*)
00430c70HYTeris!ATL::CWindow::SetWindowTextW(wchar_t*)
0040eb30HYTeris!ATL::CWindow::GetWndClassName(void)
00456770HYTeris!ATL::CWindow::MoveWindow(int,int,int,int,int)
00442ac0HYTeris!ATL::CWindow::KillTimer(unsignedint)
00455fc0HYTeris!ATL::CWindow::GetWindowTextW(wchar_t*,int)
0040ba20HYTeris!ATL::CWindow::IsWindow(void)
00441db0HYTeris!ATL::CWindow::GetParent(void)
004315b0HYTeris!ATL::CWindow::SetWindowPos(structHWND__*,int,int,int,int,unsignedint)
00456810HYTeris!ATL::CWindow::GetWindowRect(structtagRECT*)
00431860HYTeris!ATL::CWindow::GetStyle(void)
00455250HYTeris!ATL::CWindow::Invalidate(int)
004318f0HYTeris!ATL::CWindow::SetCapture(void)
00442cf0HYTeris!ATL::CWindow::SetTimer(unsignedint,unsignedint,<function>*)
00431980HYTeris!ATL::CWindow::ModifyStyle(unsignedlong,unsignedlong,unsignedint)
00443d10HYTeris!ATL::CWindow::GetDlgItemTextW(int,wchar_t*,int)
0040b980HYTeris!ATL::CWindow::SendMessageW(unsignedint,unsignedint,long)
00434be0HYTeris!ATL::CWindow::ShowWindow(int)
004d7a38HYTeris!ATL::CWindow::`RTTIBaseClassDescriptorat(0,-1,0,64)"=<notypeinformation>
004d7a04HYTeris!ATL::CWindow::`RTTIBaseClassDescriptorat(4,-1,0,64)"=<notypeinformation>
004d7a20HYTeris!ATL::CWindow::`RTTIClassHierarchyDescriptor"=<notypeinformation>
004d7a30HYTeris!ATL::CWindow::`RTTIBaseClassArray"=<notypeinformation>

我们看到CWindow只有一份，并且函数数量相比AtlWin.h减少了很多，因为ATL是以源代码的方式提供的，所有没有用到的函数不会被编译到我们最终的可执行文件中。

通过上面的分析，相信我们知道了为什么ATL/WTL大量使用模板，但是生成的exe还是这么小的原因：
不是模板不会使代码膨胀，而是ATL/WTL在设计时就关注了这个问题，它避免了在可能生成很多模板实例的模板类中编写大量代码(有些拗口，不知道你有没有读懂^_^)

总结下，如果你想用模板，但是又不想让自己最终的可执行文件变的很大，
有2种方式:
(1)你的模板类不会生成很多模板实例，这样写成模板类还有意义吗?
(2)你的模板类的代码量或是函数个数很少，你可以仿照ATL的方式把模板无关的东西用继承的方式逐层剥离，确保模板类的代码都是和模板参数相关的。

本文地址： 深入分析:C++模板究竟会使代码膨胀吗

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