How to replace CR occurences inside a string with CRLF?

Question

I tried using the std::replace algorithm:

replace(out.begin(), out.end(), '\r', '\r\n');    // error
replace(out.begin(), out.end(), "\r", "\r\n");    // error
replace(out.begin(), out.end(), "\\r", "\\r\\n"); // error

I always get errors that the parameters are ambigous. How exactly can I specify the \r and \n so the compiler will not complain ?

edit:

errors:

 could not deduce template argument for 'const _Ty &' from 'const char [5]' 
 template parameter '_Ty' is ambiguous
'replace': no matching overloaded function found

You should know better than not giving us a [Minimal, Complete, and Verifiable Example](http://stackoverflow.com/help/mcve), or posting the exact errors you get. — Some programmer dude, Jul 12 '18 at 09:07
Possible solution: https://stackoverflow.com/a/2896766/7670262 — Azeem, Jul 12 '18 at 09:26

score 3 · Accepted Answer · answered Jul 12 '18 at 10:22

While in principle this might be solved with some combination of standard/Boost functions, it's specific enough to get its own function, and thus its own impl as well. Which could be as simple as this:

std::string cr_to_crlf(std::string const& s) {
    std::string result;
    result.reserve(s.size());

    for (char c : s) {
        result += c;
        if (c == '\r') {
            result += '\n';
        }
    }
    return result;
}

How to replace CR occurences inside a string with CRLF?

1 Answers1