從std :: vector中刪除一個項目

Question

在下面的第一個代碼片段中，我試圖從一個成員函數中的一個向量中移除一個元素，該元素基於一個靜態條件函數饋入std :: remove函數。然後，我收到了第二個片段中顯示的大量模板錯誤。你能告訴我我錯過了什麼嗎？

SNIPPET 1（CODE）

void removeVipAddress(std::string &uuid) 
{ 
      struct RemoveCond 
      { 
      static bool condition(const VipAddressEntity & o) 
      { 
       return o.getUUID() == uuid; 
      } 
      }; 

      std::vector<VipAddressEntity>::iterator last = 
      std::remove(
        mVipAddressList.begin(), 
        mVipAddressList.end(), 
        RemoveCond::condition); 

      mVipAddressList.erase(last, mVipAddressList.end()); 

} 

內容片段2（編譯輸出）

/usr/include/c++/4.7/bits/random.h:4845:5: note: template<class _IntType> bool  std::operator==(const std::discrete_distribution<_IntType>&, const std::discrete_distribution<_IntType>&) 
/usr/include/c++/4.7/bits/random.h:4845:5: note: template argument deduction/substitution failed: 
In file included from /usr/include/c++/4.7/algorithm:63:0, 
      from Entity.hpp:12: 
/usr/include/c++/4.7/bits/stl_algo.h:174:4: note: ‘ECLBCP::VipAddressEntity’ is not derived from ‘const std::discrete_distribution<_IntType>’ 
In file included from /usr/include/c++/4.7/random:50:0, 
       from /usr/include/c++/4.7/bits/stl_algo.h:67, 
       from /usr/include/c++/4.7/algorithm:63, 
       from Entity.hpp:12: 
/usr/include/c++/4.7/bits/random.h:4613:5: note: template<class _RealType> bool std::operator==(const std::extreme_value_distribution<_RealType>&, const std::extreme_value_distribution<_RealType>&) 
/usr/include/c++/4.7/bits/random.h:4613:5: note: template argument deduction/substitution failed: 
In file included from /usr/include/c++/4.7/algorithm:63:0, 
      from Entity.hpp:12: 
/usr/include/c++/4.7/bits/stl_algo.h:174:4: note: ‘ECLBCP::VipAddressEntity’ is not derived from ‘const std::extreme_value_distribution<_RealType>’ 

Answer 1

我猜你正在尋找std::remove_if()，不std::remove()。

std::remove_if()接受謂詞作爲第三個參數，並刪除滿足該謂詞的元素。

std::remove()將值作爲第三個參數，並刪除與該值相等的元素。

編輯

爲了使這項工作，你還必須把你的RemoveCond定義成一個謂語的對象，因爲它需要的狀態。像這樣：

void removeVipAddress(std::string &uuid) 
{ 
     struct RemoveCond : public std::unary_function<VipAddressEntity, bool> 
     { 
     std::string uuid; 

     RemoveCond(const std::string &uuid) : uuid(uuid) {} 

     bool operator() (const VipAddressEntity & o) 
     { 
      return o.getUUID() == uuid; 
     } 
     }; 

     std::vector<VipAddressEntity>::iterator last = 
     std::remove(
       mVipAddressList.begin(), 
       mVipAddressList.end(), 
       RemoveCond(uuid)); 

     mVipAddressList.erase(last, mVipAddressList.end()); 

}