Question

I’ve a string (ifstream) with next lines:

foo
foo+..
foo

And, I’d like know how to get the line where there is a symbol + and erase the remaining lines:

foo+..

to convert the stream into a string, I use:

string stream((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());

Answer 1

How about this alternative solution:

#include <fstream>
#include <iostream>
#include <string> 
#include <vector>
#include <algorithm>

using namespace std;

bool HasNoPlus(const string &value)  
{ 
    return value.find('+') == string::npos; 
}

int main(int argc, char* argv[])   
{
    ifstream ifs("d:\\temp\\test.txt");

    vector<string> out;

    remove_copy_if(istream_iterator<string>(ifs), 
                   istream_iterator<string>(), 
                   back_inserter(out), 
                   HasNoPlus);

    return 0;
}