在C ++中使用向量和查找时未解析的外部 [英] Unresolved externals in C++ when using vectors and find

问题描述

我在一个完全独立的项目中尝试过这个代码，它工作正常（唯一的区别是，不工作的项目被导出为DLL）。以下是代码：

RTATMATHLIB.CPP

  #includestdafx.h
 #includeRTATMATHLIB.h
 #include< math.h> 
 #include< vector> 
 #include< algorithm> 
 #include< stdexcept> 
 
 using namespace std; 
 
 double someFunc（double ** Y，int length）
 {
 vector< double> myVector; 
 
 for（int i = 0; i  {
 double value =（* Y）[i] 
 
 vector< double> :: iterator it = find（myVector.begin（），myVector.end（），value）; 
 
 if（it！= myVector.end（））
 {
 continue; 
} 
 else 
 {
 myVector.push_back（value）; 
} 
} 
 return 0; 
} 
  

RTATMATHLIB.H
$ b

  __ declspec（dllexport）double someFunc（double ** Y，int length）; 
  

错误

 错误1错误LNK2019：未解析的外部符号__imp___CrtDbgReportW在函数public：__thiscall std :: _ Vector_const_iterator< double，class std :: allocator< double& class std :: allocator< double>>（double *，class std :: _ Container_base_secure const *）（?? 0？$ Vector_const_iterator @ NV？$ allocator @ N @ std @@@ std @@ QAE @ PANPBV_Container_base_secure @ 1 @@ Z）RTATMATHLIB.obj RTATMATHLIB.obj RTATMATHLIB 
错误2致命错误LNK1120：1未解析的外部
  

就是这样。我不知道为什么它在其他项目中工作，而不是这个...

解决方案

我发现了另一个论坛帖子，有人似乎报告了同样的具体问题，你有。请检查您是否有

  _DEBUG 
   
 
  
 
 
 p>看起来std :: vector认为你在构建一个调试版本，当你事实上创建一个发布版本。
 
 
 
我希望这有助于。 p> 
I have tried this code in a totally separate project, and it works fine (the only difference being that the project that is not working is being exported as a DLL). Here is the code:

RTATMATHLIB.CPP
#include "stdafx.h"
#include "RTATMATHLIB.h"
#include <math.h>
#include <vector>
#include <algorithm>
#include <stdexcept>

using namespace std;

double someFunc(double** Y, int length)
{
    vector<double> myVector;

    for(int i = 0; i < length; i++)
    {
        double value = (*Y)[i];

        vector<double>::iterator it = find(myVector.begin(), myVector.end(), value);

        if(it != myVector.end())
        {
            continue;
        }
        else
        {
            myVector.push_back(value);
        }
    }
    return 0;
}
RTATMATHLIB.H
__declspec(dllexport) double someFunc(double** Y, int length);
ERRORS
Error   1   error LNK2019: unresolved external symbol __imp___CrtDbgReportW referenced in function "public: __thiscall std::_Vector_const_iterator<double,class std::allocator<double> >::_Vector_const_iterator<double,class std::allocator<double> >(double *,class std::_Container_base_secure const *)" (??0?$_Vector_const_iterator@NV?$allocator@N@std@@@std@@QAE@PANPBV_Container_base_secure@1@@Z)  RTATMATHLIB.obj RTATMATHLIB
Error   2   fatal error LNK1120: 1 unresolved externals
And that's it. I am not sure why it works in the other project and not this one...
解决方案
I found another forum post, where somebody seems to have reported the same exact problem that you are having. Please check to see if you have
_DEBUG
defined either in your project settings (under C/C++ -- Preprocessor) or somewhere in your code (or include files).

It looks as if std::vector thinks you are building a debug build, when you are in fact creating a release build.

I hope this helps.

                        
这篇关于在C ++中使用向量和查找时未解析的外部的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！