深入分析:C++模板究竟會(huì)使代碼膨脹嗎

更新時(shí)間：2013年04月28日 14:06:37 作者：

今天和同事說到C++模板會(huì)使代碼膨脹, 可同事覺得不會(huì)。同事的依據(jù)是: 如果模板會(huì)使代碼膨脹, 那么ATL和WTL里為什么還要大量使用模板? 同樣功能，ATL和WTL編譯出的可執(zhí)行文件可比MFC編譯的要小的多

今天和同事說到C++模板會(huì)使代碼膨脹, 可同事覺得不會(huì)。
同事的依據(jù)是: 如果模板會(huì)使代碼膨脹, 那么ATL和WTL里為什么還要大量使用模板? 同樣功能，ATL和WTL編譯出的可執(zhí)行文件可比MFC編譯的要小的多。
我當(dāng)時(shí)一愣，事實(shí)確實(shí)如同事所說，難道模板會(huì)使代碼膨脹的觀點(diǎn)是錯(cuò)誤的嗎?

MFC因?yàn)楸旧泶a量和復(fù)雜性在那里，所以它生成比較大的exe無可厚非。我們這里重點(diǎn)關(guān)注為什么ATL/WTL使用模板，但是卻不會(huì)使生成的exe變大。

我們知道使用模板時(shí)，同一模板生成不同的模板實(shí)類后會(huì)是多份代碼，比如 vector<int>， vector<char>, vector<double>, 這里總共會(huì)生成3份不同的vector代碼，這就是我們平時(shí)所說的代碼膨脹。

那么為什么ATL/WTL就沒有代碼膨脹的問題呢?
我這里以 ATL里的窗口代碼為例來分析這個(gè)問題，因?yàn)槲覍?duì)WinDbg比較熟悉，下面我會(huì)以WinDbg為工具來分析我以前的寫得那個(gè)俄羅斯方塊程序。

首先我們看一下ATL的窗口代碼:

復(fù)制代碼代碼如下:

template <class T, class TBase /* = CWindow */, class TWinTraits /* = CControlWinTraits */>
class ATL_NO_VTABLE CWindowImpl : public CWindowImplBaseT< TBase, TWinTraits >
{
public:
DECLARE_WND_CLASS(NULL)

    static LPCTSTR GetWndCaption()
    {
        return NULL;
    }

    HWND Create(HWND hWndParent, _U_RECT rect = NULL, LPCTSTR szWindowName = NULL,
            DWORD dwStyle = 0, DWORD dwExStyle = 0,
            _U_MENUorID MenuOrID = 0U, LPVOID lpCreateParam = NULL)
    {
        if (T::GetWndClassInfo().m_lpszOrigName == NULL)
            T::GetWndClassInfo().m_lpszOrigName = GetWndClassName();
        ATOM atom = T::GetWndClassInfo().Register(&m_pfnSuperWindowProc);

dwStyle = T::GetWndStyle(dwStyle);
dwExStyle = T::GetWndExStyle(dwExStyle);

        // set caption
        if (szWindowName == NULL)
            szWindowName = T::GetWndCaption();

        return CWindowImplBaseT< TBase, TWinTraits >::Create(hWndParent, rect, szWindowName,
            dwStyle, dwExStyle, MenuOrID, atom, lpCreateParam);
    }
};

上面是一個(gè)模板類，它應(yīng)該會(huì)生成多份模板實(shí)例代碼：我們可以用WinDbg的符號(hào)搜索命令來做驗(yàn)證:
輸入 x HYTeris!ATL::CWindowImpl<* ，搜索所有以 HYTeris!ATL::CWindowImpl< 開頭的符號(hào)

復(fù)制代碼代碼如下:

0:000> x HYTeris!ATL::CWindowImpl<*
004592f0 HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
004343a0 HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00437c90 HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
00430440 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> >::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> > (void)
0041c990 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
0044cf50 HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
004539a0 HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00435800 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00434640 HYTeris!ATL::CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
00437440 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> >::GetWndCaption (void)
00436020 HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00453f70 HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
00424e30 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
004338a0 HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
0041c4f0 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00441b50 HYTeris!ATL::CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
004365f0 HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00455120 HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
0040ea20 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00453fa0 HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
0041abc0 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00459c20 HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
0045f640 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
004608a0 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndClassInfo (void)
0045fed0 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00433a70 HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00437c60 HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
0044fb70 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
0041acf0 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00459510 HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
00437a90 HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
00430490 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> >::~CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> > (void)
00424de0 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00433ac0 HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00433850 HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00433b60 HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00452050 HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
0044f8e0 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
0044cec0 HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
004340e0 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00433ef0 HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
004348c0 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::~CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > > (void)
004535b0 HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
00454170 HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
00459c70 HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00451ed0 HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00451f20 HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
0045c4b0 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00436320 HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
004536a0 HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
004604a0 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::GetWndCaption (void)
0040eca0 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
0045ff90 HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
00437cc0 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
004366e0 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
0045e620 HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
004608d0 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndCaption (void)
004520a0 HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
0045d210 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > > (void)
004d84a8 HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d84b8 HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d7970 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d7960 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d914c HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8dd0 HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8b04 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d8b14 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d8ae8 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004e31b8 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004e2980 HYTeris!ATL::CWindowImpl<CTsMainDisplayPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d88c4 HYTeris!ATL::CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8330 HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d88f0 HYTeris!ATL::CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d88e0 HYTeris!ATL::CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d8a40 HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004e30f0 HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d8a5c HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d8a6c HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004e21d0 HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d8c70 HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004e2e78 HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004e1f00 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> > `RTTI Type Descriptor' = <no type information>
004d9208 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d9218 HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004e1ad8 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d834c HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d835c HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d8c9c HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d8c8c HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d856c HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d855c HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004e2bb8 HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d7fa0 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d7fb0 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d91ec HYTeris!ATL::CWindowImpl<CTsSingleControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004e2048 HYTeris!ATL::CWindowImpl<CTsMainButtonPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d8174 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d8184 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> >::`RTTI Base Class Array' = <no type information>
004d8dfc HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d8dec HYTeris!ATL::CWindowImpl<CTsMutiScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004e2728 HYTeris!ATL::CWindowImpl<CTsKeyEdit,WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004e28c8 HYTeris!ATL::CWindowImpl<CTsNextElementContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d8fac HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d8f9c HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d848c HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8f80 HYTeris!ATL::CWindowImpl<CTsButton,WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8158 HYTeris!ATL::CWindowImpl<CTsGameMainWnd,ATL::CWindow,ATL::CWinTraits<114229248,262400> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8540 HYTeris!ATL::CWindowImpl<CTsMainStatusPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d7944 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d7f84 HYTeris!ATL::CWindowImpl<CTsDisplayContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004e2aa0 HYTeris!ATL::CWindowImpl<CTsSingleScoreContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d9168 HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d9178 HYTeris!ATL::CWindowImpl<CTsSubControlContainer,ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004e1628 HYTeris!ATL::CWindowImpl<CTsAgentWindow,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004e2148 HYTeris!ATL::CWindowImpl<CTsMainControlPane,ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d95c4 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::`RTTI Base Class Array' = <no type information>
004d95b4 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::`RTTI Class Hierarchy Descriptor' = <no type information>
004e3400 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > > `RTTI Type Descriptor' = <no type information>
004d9598 HYTeris!ATL::CWindowImpl<CTsUserListCtrl,WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>

上面的符號(hào)可以驗(yàn)證我們多份實(shí)例的猜想。
可以看到 CWindowImpl和我們的窗口繼承類（T），窗口基類(TBase), 窗口風(fēng)格（TWinTraits）相關(guān)，所以數(shù)量很多。那么為什么這么多的符號(hào)，也就是這么多的函數(shù)代碼，exe大小沒有被撐大？
那時(shí)因?yàn)镃WindowImpl類函數(shù)本身很小，我們從函數(shù)的代碼量上就可以看出來。

用同樣的方法，我們可以繼續(xù)分析 CWindowImplBaseT

復(fù)制代碼代碼如下:

template <class TBase = CWindow, class TWinTraits = CControlWinTraits>
class ATL_NO_VTABLE CWindowImplBaseT : public CWindowImplRoot< TBase >
{
public:
WNDPROC m_pfnSuperWindowProc;

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

    static DWORD GetWndStyle(DWORD dwStyle)
    {
        return TWinTraits::GetWndStyle(dwStyle);
    }
    static DWORD GetWndExStyle(DWORD dwExStyle)
    {
        return TWinTraits::GetWndExStyle(dwExStyle);
    }

    virtual WNDPROC GetWindowProc()
    {
        return WindowProc;
    }
    static LRESULT CALLBACK StartWindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
    static LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
    HWND Create(HWND hWndParent, _U_RECT rect, LPCTSTR szWindowName,
            DWORD dwStyle, DWORD dwExStyle, _U_MENUorID MenuOrID, ATOM atom, LPVOID lpCreateParam = NULL);
    BOOL DestroyWindow()
    {
        ATLASSERT(::IsWindow(m_hWnd));
        return ::DestroyWindow(m_hWnd);
    }
    BOOL SubclassWindow(HWND hWnd);
    HWND UnsubclassWindow(BOOL bForce = FALSE);

    LRESULT DefWindowProc()
    {
        const _ATL_MSG* pMsg = m_pCurrentMsg;
        LRESULT lRes = 0;
        if (pMsg != NULL)
            lRes = DefWindowProc(pMsg->message, pMsg->wParam, pMsg->lParam);
        return lRes;
    }

    LRESULT DefWindowProc(UINT uMsg, WPARAM wParam, LPARAM lParam)
    {
#ifdef STRICT
        return ::CallWindowProc(m_pfnSuperWindowProc, m_hWnd, uMsg, wParam, lParam);
#else
        return ::CallWindowProc((FARPROC)m_pfnSuperWindowProc, m_hWnd, uMsg, wParam, lParam);
#endif
    }

    virtual void OnFinalMessage(HWND /*hWnd*/)
    {
        // override to do something, if needed
    }
};

復(fù)制代碼代碼如下:

0:000> x HYTeris!ATL::CWindowImplBaseT<*
0040f170 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, unsigned short, void *)
0040ec20 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndStyle (unsigned long)
00435970 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::OnFinalMessage (struct HWND__ *)
004604d0 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::GetWndStyle (unsigned long)
00434a10 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::~CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
0040ec60 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWndExStyle (unsigned long)
00461740 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::WindowProc (struct HWND__ *, unsigned int, unsigned int, long)
0044c040 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::WindowProc (struct HWND__ *, unsigned int, unsigned int, long)
004346e0 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::~CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
0041c440 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00435940 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::GetWindowProc (void)
00459580 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::GetWndExStyle (unsigned long)
00461950 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, unsigned short, void *)
004395b0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::StartWindowProc (struct HWND__ *, unsigned int, unsigned int, long)
00439ea0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::DefWindowProcW (unsigned int, unsigned int, long)
00461620 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::StartWindowProc (struct HWND__ *, unsigned int, unsigned int, long)
004596e0 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, unsigned short, void *)
0041ced0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::WindowProc (struct HWND__ *, unsigned int, unsigned int, long)
0044c370 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::UnsubclassWindow (int)
00460510 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::GetWndExStyle (unsigned long)
00457f70 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::WindowProc (struct HWND__ *, unsigned int, unsigned int, long)
0045f830 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::GetWindowProc (void)
00457820 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
004374b0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::GetWndExStyle (unsigned long)
00434ad0 HYTeris!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)
004595c0 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::StartWindowProc (struct HWND__ *, unsigned int, unsigned int, long)
004358f0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> > (void)
00445920 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::OnFinalMessage (struct HWND__ *)
00461ad0 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::DefWindowProcW (unsigned int, unsigned int, long)
0041c4c0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::OnFinalMessage (struct HWND__ *)
00437470 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::GetWndStyle (unsigned long)
004398e0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::Create (struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, unsigned short, void *)
0040ed50 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::StartWindowProc (struct HWND__ *, unsigned int, unsigned int, long)
004458a0 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > (void)
0045f7e0 HYTeris!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)
0041ad30 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::~CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> > (void)
00430550 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::~CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> > (void)
0045f860 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::OnFinalMessage (struct HWND__ *)
004582a0 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::UnsubclassWindow (int)
0041c490 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::GetWindowProc (void)
0044cb50 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::DefWindowProcW (unsigned int, unsigned int, long)
0044c250 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::SubclassWindow (struct HWND__ *)
004458f0 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::GetWindowProc (void)
00459540 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::GetWndStyle (unsigned long)
00458180 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::SubclassWindow (struct HWND__ *)
00457870 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::GetWindowProc (void)
00457910 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::OnFinalMessage (struct HWND__ *)
0040e990 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::DestroyWindow (void)
004396d0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::WindowProc (struct HWND__ *, unsigned int, unsigned int, long)
0041d1c0 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::DefWindowProcW (unsigned int, unsigned int, long)
004578a0 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::DefWindowProcW (unsigned int, unsigned int, long)
004d8fc8 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8ff4 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d8fe4 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d79b4 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d79a4 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004e2798 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d819c HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d8938 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Array' = <no type information>
004d8928 HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d960c HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::`RTTI Base Class Array' = <no type information>
004d95fc HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::`RTTI Class Hierarchy Descriptor' = <no type information>
004e2ee8 HYTeris!ATL::CWindowImplBaseT<WTL::CButtonT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d81c8 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::`RTTI Base Class Array' = <no type information>
004d81b8 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004e34a0 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > > `RTTI Type Descriptor' = <no type information>
004d95e0 HYTeris!ATL::CWindowImplBaseT<WTL::CListViewCtrlT<ATL::CWindow>,ATL::CWinTraitsOR<32777,0,ATL::CWinTraits<1442840576,0> > >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004e1f68 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<114229248,262400> > `RTTI Type Descriptor' = <no type information>
004e1688 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> > `RTTI Type Descriptor' = <no type information>
004d7988 HYTeris!ATL::CWindowImplBaseT<ATL::CWindow,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d890c HYTeris!ATL::CWindowImplBaseT<WTL::CEditT<ATL::CWindow>,ATL::CWinTraits<1442840576,0> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>

可以看到 CWindowImplBaseT只與窗口基類和窗口風(fēng)格相關(guān) ，數(shù)量已經(jīng)減小很多，CWindowImplBaseT模板類本身函數(shù)數(shù)量不多，函數(shù)代碼量大小也不大。

然后再看CWindowImplRoot,

復(fù)制代碼代碼如下:

template <class TBase /* = CWindow */>
class ATL_NO_VTABLE CWindowImplRoot : public TBase, public CMessageMap
{
public:
    CWndProcThunk m_thunk;
    const _ATL_MSG* m_pCurrentMsg;
    DWORD m_dwState;

enum { WINSTATE_DESTROYED = 0x00000001 };

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

    virtual ~CWindowImplRoot()
    {
#ifdef _DEBUG
        if(m_hWnd != NULL)    // should be cleared in WindowProc
        {
            ATLTRACE(atlTraceWindowing, 0, _T("ERROR - Object deleted before window was destroyed\n"));
            ATLASSERT(FALSE);
        }
#endif //_DEBUG
    }

// Current message
    const _ATL_MSG* GetCurrentMessage() const
    {
        return m_pCurrentMsg;
    }

    // "handled" management for cracked handlers
    BOOL IsMsgHandled() const
    {
        const _ATL_MSG* pMsg = GetCurrentMessage();
        ATLASSERT(pMsg != NULL);
        ATLASSERT(pMsg->cbSize >= sizeof(_ATL_MSG));
        return pMsg->bHandled;
    }
    void SetMsgHandled(BOOL bHandled)
    {
        _ATL_MSG* pMsg = (_ATL_MSG*)GetCurrentMessage();    // override const
        ATLASSERT(pMsg != NULL);
        ATLASSERT(pMsg->cbSize >= sizeof(_ATL_MSG));
        pMsg->bHandled = bHandled;
    }

// Message forwarding and reflection support
    LRESULT ForwardNotifications(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled);
    LRESULT ReflectNotifications(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled);
    static BOOL DefaultReflectionHandler(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT& lResult);
};

復(fù)制代碼代碼如下:

0:000> x HYTeris!ATL::CWindowImplRoot*
004364d0 HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> >::~CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> > (void)
004367d0 HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow> >::~CWindowImplRoot<WTL::CEditT<ATL::CWindow> > (void)
00457c30 HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow> >::CWindowImplRoot<WTL::CButtonT<ATL::CWindow> > (void)
00460550 HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> >::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> > (void)
004479d0 HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow> >::CWindowImplRoot<WTL::CEditT<ATL::CWindow> > (void)
0041c360 HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::~CWindowImplRoot<ATL::CWindow> (void)
00435f40 HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow> >::~CWindowImplRoot<WTL::CButtonT<ATL::CWindow> > (void)
004613f0 HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::ForwardNotifications (unsigned int, unsigned int, long, int *)
00438f50 HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::ReflectNotifications (unsigned int, unsigned int, long, int *)
0041c8e0 HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::CWindowImplRoot<ATL::CWindow> (void)
004e2800 HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow> > `RTTI Type Descriptor' = <no type information>
004d897c HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow> >::`RTTI Base Class Array' = <no type information>
004d896c HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d9640 HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d9650 HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> >::`RTTI Base Class Array' = <no type information>
004d8950 HYTeris!ATL::CWindowImplRoot<WTL::CEditT<ATL::CWindow> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d9028 HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow> >::`RTTI Class Hierarchy Descriptor' = <no type information>
004d9038 HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow> >::`RTTI Base Class Array' = <no type information>
004e16dc HYTeris!ATL::CWindowImplRoot<ATL::CWindow> `RTTI Type Descriptor' = <no type information>
004e3530 HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> > `RTTI Type Descriptor' = <no type information>
004d9624 HYTeris!ATL::CWindowImplRoot<WTL::CListViewCtrlT<ATL::CWindow> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d79c8 HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004e2f58 HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow> > `RTTI Type Descriptor' = <no type information>
004d79f4 HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::`RTTI Base Class Array' = <no type information>
004d79e4 HYTeris!ATL::CWindowImplRoot<ATL::CWindow>::`RTTI Class Hierarchy Descriptor' = <no type information>
004d900c HYTeris!ATL::CWindowImplRoot<WTL::CButtonT<ATL::CWindow> >::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>

可以看到 CWindowImplRoot只和窗口基類(CWindow)相關(guān) ，所以相關(guān)的符號(hào)就更少了。

最后我們再看一下CWindow:

復(fù)制代碼代碼如下:

0:000> x HYTeris!ATL::CWindow::*
004e1000 HYTeris!ATL::CWindow::rcDefault = struct tagRECT
00442a20 HYTeris!ATL::CWindow::DestroyWindow (void)
00425730 HYTeris!ATL::CWindow::InvalidateRect (struct tagRECT *, int)
00442340 HYTeris!ATL::CWindow::CenterWindow (struct HWND__ *)
00425850 HYTeris!ATL::CWindow::UpdateWindow (void)
0041c950 HYTeris!ATL::CWindow::CWindow (struct HWND__ *)
004391e0 HYTeris!ATL::CWindow::GetDlgItem (int)
004568a0 HYTeris!ATL::CWindow::SetWindowRgn (struct HRGN__ *, int)
00441d20 HYTeris!ATL::CWindow::GetWindowLongW (int)
00444350 HYTeris!ATL::CWindow::Create (wchar_t *, struct HWND__ *, class ATL::_U_RECT, wchar_t *, unsigned long, unsigned long, class ATL::_U_MENUorID, void *)
004391b0 HYTeris!ATL::CWindow::operator HWND__ * (void)
00459080 HYTeris!ATL::CWindow::EnableWindow (int)
00425140 HYTeris!ATL::CWindow::GetClientRect (struct tagRECT *)
00430c70 HYTeris!ATL::CWindow::SetWindowTextW (wchar_t *)
0040eb30 HYTeris!ATL::CWindow::GetWndClassName (void)
00456770 HYTeris!ATL::CWindow::MoveWindow (int, int, int, int, int)
00442ac0 HYTeris!ATL::CWindow::KillTimer (unsigned int)
00455fc0 HYTeris!ATL::CWindow::GetWindowTextW (wchar_t *, int)
0040ba20 HYTeris!ATL::CWindow::IsWindow (void)
00441db0 HYTeris!ATL::CWindow::GetParent (void)
004315b0 HYTeris!ATL::CWindow::SetWindowPos (struct HWND__ *, int, int, int, int, unsigned int)
00456810 HYTeris!ATL::CWindow::GetWindowRect (struct tagRECT *)
00431860 HYTeris!ATL::CWindow::GetStyle (void)
00455250 HYTeris!ATL::CWindow::Invalidate (int)
004318f0 HYTeris!ATL::CWindow::SetCapture (void)
00442cf0 HYTeris!ATL::CWindow::SetTimer (unsigned int, unsigned int, <function> *)
00431980 HYTeris!ATL::CWindow::ModifyStyle (unsigned long, unsigned long, unsigned int)
00443d10 HYTeris!ATL::CWindow::GetDlgItemTextW (int, wchar_t *, int)
0040b980 HYTeris!ATL::CWindow::SendMessageW (unsigned int, unsigned int, long)
00434be0 HYTeris!ATL::CWindow::ShowWindow (int)
004d7a38 HYTeris!ATL::CWindow::`RTTI Base Class Descriptor at (0,-1,0,64)' = <no type information>
004d7a04 HYTeris!ATL::CWindow::`RTTI Base Class Descriptor at (4,-1,0,64)' = <no type information>
004d7a20 HYTeris!ATL::CWindow::`RTTI Class Hierarchy Descriptor' = <no type information>
004d7a30 HYTeris!ATL::CWindow::`RTTI Base Class Array' = <no type information>

我們看到CWindow只有一份，并且函數(shù)數(shù)量相比AtlWin.h減少了很多，因?yàn)锳TL是以源代碼的方式提供的，所有沒有用到的函數(shù)不會(huì)被編譯到我們最終的可執(zhí)行文件中。

通過上面的分析，相信我們知道了為什么ATL/WTL大量使用模板，但是生成的exe還是這么小的原因：
不是模板不會(huì)使代碼膨脹，而是ATL/WTL在設(shè)計(jì)時(shí)就關(guān)注了這個(gè)問題，它避免了在可能生成很多模板實(shí)例的模板類中編寫大量代碼(有些拗口，不知道你有沒有讀懂^_^)

總結(jié)下，如果你想用模板，但是又不想讓自己最終的可執(zhí)行文件變的很大，
有2種方式:
(1)你的模板類不會(huì)生成很多模板實(shí)例，這樣寫成模板類還有意義嗎?
(2)你的模板類的代碼量或是函數(shù)個(gè)數(shù)很少，你可以仿照ATL的方式把模板無關(guān)的東西用繼承的方式逐層剝離，確保模板類的代碼都是和模板參數(shù)相關(guān)的。

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