为什么将字符串向量值转换为 cstring 不等同于手动写入字符串？

i有一个输入文件，该文件包含一个.txt文件列表中的文件夹中。我可以循环浏览输入文件，然后将.txt文件文件ply放在字符串向量中。但是，当我尝试使用sections向量中的一个filepath打开另一个ifstream（字符串向量值转换为cstring）时，

std::ifstream secFile(sections[i].c_str());

行secFile.fail()返回真实的含义，含义失败。如果我使用当前评论的线，该线硬编码是filepath（手动编写字符串），而不是从向量中获取

//std::ifstream secFile("test2/main0.txt");

它不再失败。我什至尝试将sections[0].c_str()和"test2/main0.txt"输出到文本文件中，每个文本的文本完全相同。我什至比较了文本文件的十六进制值，并且没有看不见的字符可能引起这样的问题。

知道问题可能是什么？

这是我的代码：

#include <fstream>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cstring>
//using namespace std;

int main (int argc, char* argv[]){
    if(argc != 2){
        return(0);
    }
    std::vector<std::string> sections;
    std::vector<std::string> overlaps;
    std::ifstream file(argv[1]);
    std::string str;
    std::string secLine;
    std::string overlapLine;
    std::string strLow;
    std::string wholePage = "";
    //determine if input text file is overlap text or main text
    while (getline(file, str))
    {
        if (str.find("overlap")!=-1){
            overlaps.push_back(str);
        }
        else{
            sections.push_back(str);
        }
    }
    file.clear();
    for(int i = 0; i < sections.size();i++){
        //HERE IS MY QUESTION
        std::ifstream secFile(sections[i].c_str());
        //std::ifstream secFile("test2/main0.txt");
        if(secFile.good()){
            std::cout << "ngood4n";
        }
        if(secFile.bad()){
            std::cout << "bad4n";
        }
        if(secFile.fail()){
            std::cout << "fail4n";
        }
        if(secFile.eof()){
            std::cout << "eof4n";
        }
        int secLength = 0;
        //determine number of files in test2/
        while (getline(secFile,secLine)){
            secLength++;
        }
        secfile.clear();
        secfile.seekg(0);
        int j = 0;
        while (getline(secFile,secLine)){
            if (i == 0 && j==0){
                wholePage += std::string(secLine) + "n";
            }
            else if(j==0){
                //do nothing
            }
            else if(i == (sections.size()-1) && j == secLength){
                wholePage += std::string(secLine) + "n";
            }
            else if(j == secLength){
                //do nothing
            }
            else{
                wholePage += std::string(secLine) + "n";
            }
            j++;
        }
        int k = 0;
        if(i < sections.size()-1){ 
            std::ifstream overFile(overlaps[i].c_str());
            int overLength = 0;
            while (getline(overFile,overlapLine)){
                overLength++;
            }
            while (getline(overFile,overlapLine)){
                std::cout << "Hi5";
                if(k == 0){
                    //do nothing
                }
                else if(k == overLength){
                    //do nothing
                }
                else{
                    if (wholePage.find(overlapLine)){
                        //do nothing
                    }
                    else{
                        wholePage += std::string(secLine) + "n";
                    }
                }
            }
            k++;
        }
    }
    std::ofstream out("output.txt");
    out << wholePage;
    out.close();
    std::cout << "n";
    return 0;

}