C++: std::ofstream method open() wipes open ifstream file on second iteration

Question

I am trying to build a "fileUpdater" which will copy an original file into multiple directories, where a file with the same name and extension was previously found.

bool update_files(const string inputPath, const vector<string> outputPaths)
{
    ifstream src(inputPath);
    if(!src.is_open())
    {
        cout << "Unable to open input file\n" << inputPath <<endl;
        return false;
    }
    else
    {
        ofstream dst;
        for(unsigned int i=0; i<= outputPaths.size()-1; i++)
        {
            dst.open(outputPaths[i]);
            try
            {
                dst << src.rdbuf();
                dst.close();
            }
            catch(int e)
            {
                cout << "Unable to replace file\n" <<endl;
                cout << outputPaths[i] <<"\n"<< endl;
                cout << "Error code: " <<e<<endl;
            }
        }
    };
    src.close();
    return true;
}

Exactly after executing

dst.open(outputPaths[i]);

in the second iteration, the original file opened by

ifstream src(inputPath);

gets wiped and only an empty file is copied into the remaining directories. I also tried

dst.clear();
dst.close();

and

src.clear();
src.seekg(0,ios::beg);

before entering the next iteration, but it made no difference.

UPDATE After trying different files, I realised the behavior depends on the input file. Above behavior appeared for .m-files (MatLab). After testing it with .txt files, all files were wiped.

Answer 1

None of the proposed methods work. Neither resetting the pointer, nor pulling ifstream into the loop, which would result in opening the input file (which is not supposed to change) unnecessarily often.

It is still unclear why dst.open(outputPaths[i]); is wiping the input file. Also the exact moment of the wipe depends on used types of files.

I implemented following workaround, effectively reading the input file into a string and closing it beforehand, in order to protect it from further read/write action.

bool update_files( const string inputPath, const vector<string> outputPaths)
{
    const char * in = inputPath.c_str();
    ifstream src(in);
    if(!src.is_open())
    {
        cout << "Unable to open input file\n" << inputPath <<endl;
        return false;
    }
    else
    {
        string buffer;
        streamsize s=src.gcount();
        src.seekg(0,ios::end);
        buffer.reserve(src.tellg());
        src.seekg(0,ios::beg);
        buffer.assign((istreambuf_iterator<char>(src)), istreambuf_iterator<char>());
        src.close();

        for(unsigned int i=0; i<= outputPaths.size()-1; i++)
        {
            const char * out = outputPaths[i].c_str();
            ofstream dst(out);
            try
            {
                dst << buffer;
                dst.close();
            }
            catch(int e)
            {
                cout << "Unable to replace file\n" <<endl;
                cout << outputPaths[i] <<"\n"<< endl;
                cout << "Error code: " <<e<<endl;
            }
        }
    };
    src.close();
    return true;
}