[問題] template一問

看板C_and_CPP作者gogohata (沒有不可能)時間14年前 (2011/11/10 17:52)推噓5(5推 0噓 29→)

留言34則, 7人參與討論串8/9 (看更多)

開發平台(Platform): (Ex: VC++, GCC, Linux, ...) Visual C++ 2008 問題(Question)： TEnMap與STL的Map操作類似請問一下第二個class CItemInfoPool::AddItemInfo 裡面為何可以直接這樣寫 pNewItemInfo->SetItemCode(strItemCode); 她是怎麼解析到T為CItemInfoBase? 另外我如果把<typename T> 代成其他類型,像int,這樣是不是就error了? //Source Code class CItemInfoBase { public: typedef TEnMap<CEnAString, CItemInfoBase*> ItemInfoMAP; typedef ItemInfoMAP::iterator ItemInfoMAP_ITER; typedef ItemInfoMAP::const_iterator ItemInfoMAP_CITER; typedef ItemInfoMAP::reverse_iterator ItemInfoMAP_RITER; typedef ItemInfoMAP::const_reverse_iterator ItemInfoMAP_CRITER; typedef ItemInfoMAP::value_type ItemInfoMAP_VTYPE; /* 中略 */ public: CItemInfoBase& operator = (const CItemInfoBase& info) { m_strItemCode = info.m_strItemCode; return *this; } public: void SetItemCode(const CEnAString& strItemCode){m_strItemCode=strItemCode;} const CEnAString& GetItemCode() const {return m_strItemCode;} protected: CEnAString m_strItemCode; }; //------------------------------------------------------------------------- class CItemInfoPool { public: /* 中略 */ template <typename T> T* AddItemInfo(const CEnAString& strItemCode, const T& ItemInfo) { CItemInfoBase::ItemInfoMAP_ITER found=m_mapItemInfos.find(strItemCode); if (found != m_mapItemInfos.end()) return (T*)found->second; T* pNewItemInfo = new T; *pNewItemInfo = ItemInfo; pNewItemInfo->SetItemCode(strItemCode); m_mapItemInfos[strItemCode] = pNewItemInfo; m_iNumOfItemInfos++; return pNewItemInfo; } const CItemInfoBase::ItemInfoMAP& GetItemInfos() const{return m_mapItemInfos;} protected: CItemInfoBase::ItemInfoMAP m_mapItemInfos; }; -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 59.120.1.136 ※ 編輯: gogohata 來自: 59.120.1.136 (11/10 17:53) ※ 編輯: gogohata 來自: 59.120.1.136 (11/10 17:54)

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