错误：没有匹配函数调用‘std::vector<std::vector<int>>::push_back(std::vector<std::__cxx11::basic_string<char> >&)’

Question

我正在尝试从我的主管那里调试此代码，而且我是 C++ 新手。

我发现了一些类似的 no matching function for call to 问题，这让我知道了问题可能是什么但无法解决。

我在错误信息和相关功能下方列出了我的想法。

错误信息：

In function ‘int main(int, char**)’:
distanceMatrixToSageGraph.c:104:43: error: no matching function for call to 
‘std::vector<std::vector<int>>::push_back(std::vector<std::__cxx11::basic_string<char> >&)’     
the_entries.push_back( row_as_vector );

相关功能：

int main(int argc, char** threshold_and_distanceMatrixfilename)
{
    if (argc < 2 || argc > 2) 
    {
        std::cerr << "Usage: ./distanceMatrixToSageGraph.o <threshold> 

            <distanceMatrix_file_calculated_fromDGEsingleCell_data>" << std::endl;
            return -1;
    }
    string distanceMatrixfilename = threshold_and_distanceMatrixfilename[2];
    int threshold = std::stoi(threshold_and_distanceMatrixfilename[1]);
    std::ifstream distanceMatrixFile(distanceMatrixfilename);

    if (!distanceMatrixFile)
    {
        std::cerr << "Error opening distanceMatrix file: " << distanceMatrixfilename << std::endl;
        return -1;
    }
    string row;
    std::getline(distanceMatrixFile, row); // discard the first row, which specifies the format of the file.
    vector<vector<int>> the_entries;

    while (std::getline(distanceMatrixFile, row))
    {
        std::stringstream row_as_stringstream(row);
        int i; i = 0;
        vector<string> row_as_vector;

        while (row_as_stringstream.good())
        {
            string substr;
            getline(row_as_stringstream, substr, ',');
            row_as_vector.push_back(substr);
        };
        the_entries.push_back(row_as_vector); //LINE 104
    };
}

想法：

• 如果有人能给我解释一下就好了：std::vector<std::vector<int>>::push_back(std::vector<std::__cxx11::basic_string<char>>&)
• 我知道std::vector<std::vector<int>> 是一个矩阵并且 push_back 在向量末尾添加一个元素。
• 我怀疑我们正在尝试读取错误的类型 the_entries.push-back(row_as_vector)。

• 原始代码以csv 文件作为输入，包含integers 和strings。现在我们正在读取具有以下形状的txt 文件：

  TEXT 0; INT; INT; INT; INT; ... 0; INT; INT; INT; INT; ... 18 more lines of the above numbers and semicolons

  在上面，我们删除了89 行中的第一行。

• 代码是否可能需要进行更多更改才能 阅读这个txt 文件而不是csv 文件？

错误信息的其余部分：

In file included from /usr/include/c++/6/vector:64:0,
                 from distanceMatrixToSageGraph.c:13:
/usr/include/c++/6/bits/stl_vector.h:914:7: note: candidate: void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; std::vector<_Tp, _Alloc>::value_type = std::vector<int>]
       push_back(const value_type& __x)
       ^~~~~~~~~
/usr/include/c++/6/bits/stl_vector.h:914:7: note:   no known conversion for argument 1 from ‘std::vector<std::__cxx11::basic_string<char> >’ to ‘const value_type& {aka const std::vector<int>&}’
/usr/include/c++/6/bits/stl_vector.h:932:7: note: candidate: void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = std::vector<int>; _Alloc = std::allocator<std::vector<int> >; std::vector<_Tp, _Alloc>::value_type = std::vector<int>]
       push_back(value_type&& __x)
       ^~~~~~~~~
/usr/include/c++/6/bits/stl_vector.h:932:7: note:   no known conversion for argument 1 from ‘std::vector<std::__cxx11::basic_string<char> >’ to ‘std::vector<std::vector<int> >::value_type&& {aka std::vector<int>&&}’

完整代码：

// Convert distanceMatrix tables of protein interactions to SAGE graph.
///////////////////////////////////////////////////////////////////////////
#include <iostream>
#include <fstream>
#include <sstream>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <list>
#include <vector>
#include <tuple>
#include <algorithm>
using namespace std;

void writeGraphInSageFormat(string name, std::vector<std::vector<int>> TheEdges) 
{
    //////////////////////////////////////////////////////////////////////////////////////
    // Write out the edges in SAGE format.
    ///////////////////////////////////////////////////////////////////////////////////////
    int edgeNumber = TheEdges.size();
    ofstream d1sageFile(name, ios::out);
    d1sageFile << "g = Graph([" << endl;

    for (int n = 0; n < edgeNumber; n++) {
        d1sageFile << "(" << TheEdges[n][0] + 1 << "," << TheEdges[n][1] + 1 << ")," << endl;
    }
    d1sageFile << "])" << endl;
    d1sageFile << "g.show()" << endl;
    d1sageFile.close();
    std::cout << "SAGE graph written into the file " << name << std::endl;
}

std::vector<std::vector<int>> ConvertEntriesMatrixToEdges(vector<vector<int>> the_entries, int threshold) 
{
    ////////////////////////////////////////////////////////////////////////////////////////////
    // Construct the edge-vertex incidence matrix (d_1) from the distanceMatrix entries matrix:
    ////////////////////////////////////////////////////////////////////////////////////////////
    std::vector<std::string> proteinNames;
    std::vector<std::vector<int>> TheEdges;
    std::cout << "Registering only edges shorter than " << threshold << "." << std::endl;
    int thisDistance;
    for (int i = 0; i < the_entries.size(); i++)
    {
        for (int j = i + 1; j < the_entries.size(); j++)
        {
            // we could use the_entries.size() instead of the_entries.at(i).size(), because this is a square matrix.
            thisDistance = the_entries.at(i).at(j);
            if (thisDistance < threshold) 
            {
                std::vector<int> CurrentEdge(2);
                CurrentEdge[0] = i;
                CurrentEdge[1] = j;
                TheEdges.push_back(CurrentEdge);
            };
        };
    };
    return TheEdges;
}

///////////////////////////////////////////
// Main Program: Extract edges from a distanceMatrix file.
///////////////////////////////////////////
int main(int argc, char** threshold_and_distanceMatrixfilename)
{
    if (argc < 2 || argc > 2)
    {
        std::cerr << "Usage: ./distanceMatrixToSageGraph.o <threshold> <distanceMatrix_file_calculated_fromDGEsingleCell_data>" << std::endl;
        return -1;
    }
    string distanceMatrixfilename = threshold_and_distanceMatrixfilename[2];
    int threshold = std::stoi(threshold_and_distanceMatrixfilename[1]);
    std::ifstream distanceMatrixFile(distanceMatrixfilename);
    if (!distanceMatrixFile) {
        std::cerr << "Error opening distanceMatrix file: " << distanceMatrixfilename << std::endl;
        return -1;
    }
    string row;  //LINE 88
    std::getline(distanceMatrixFile, row); // discard the first row, which specifies the format of the file.
    vector<vector<int>> the_entries;

    while (std::getline(distanceMatrixFile, row))
    {
        std::stringstream row_as_stringstream(row);
        int i; i = 0;
        vector<string> row_as_vector;
        while (row_as_stringstream.good())
        {
            string substr;
            getline(row_as_stringstream, substr, ',');
            row_as_vector.push_back(substr);
        };
        the_entries.push_back(row_as_vector); //LINE 104
    };
    ////////////////////////////////////////////////////////////
    // Now we assemble the entries to an edges matrix, and write it into a Sage file:
    ////////////////////////////////////////////////////////////
    std::vector<std::vector<int>> TheEdges = ConvertEntriesMatrixToEdges(the_entries, threshold);    
    char outputFilename[60]; strcpy(outputFilename, distanceMatrixfilename.c_str()); strcat(outputFilename, "AtThreshold"); string thrshld = std::to_string(threshold); strcat(outputFilename, thrshld.c_str()); strcat(outputFilename, ".txt");
    writeGraphInSageFormat(outputFilename, TheEdges);
    return 0;
}

Answer 1

我怀疑我们正在尝试读取错误的类型 the_entries.push-back(row_as_vector)

error: no matching function for call to 
‘std::vector<std::vector<int>>::push_back(std::vector<std::__cxx11::basic_string<char> >&)’     
the_entries.push_back( row_as_vector );

是的，你说得对。错误消息表明您正在尝试将 字符串向量 推回 整数向量向量。它们是完全不同的类型，因此不可能。

您可能希望将the_entries 的类型更改为

std::vector<std::vector<std::string>> the_entries;
//                      ^^^^^^^^^^^^

或

使用std::stoi 将字符串转换为整数，同时推回std::vector<int> row_as_vector。

std::vector<int> row_as_vector;
while(row_as_stringstream.good())
{
        // ......
        row_as_vector.push_back(std::stoi(substr));
        //                     ^^^^^^^^^^^^^^^^^^^
};
the_entries.push_back( row_as_vector );

---

是否有可能代码必须进行更多更改才能阅读 这个txt 文件而不是csv 文件？

如果这两者的内容相同，则无需对代码进行太大改动。但是，; 应该是 parsed out，然后再调用 std::stoi 给他们。因为它可能通过 invalid_argument 异常为坏参数。

---

一些建议：

• 考虑不要使用using namespace std; 练习。看到这个帖子 更多： Why is "using namespace std;" considered bad practice?
• 当您传递非原始类型时（即std::string， std::vector.. 等）到函数，考虑这种情况，如果 参数是否为只读。如果要修改数据 pass-by-ref 并且如果是只读的（不应在函数内部进行任何修改），则通过 const-ref 传递它们。阅读更多： How to pass objects to functions in C++?