C++ String-Replace-All

// A helper function to replace "all" occurances of "src" with "dest" in a C++ string. (collected)
string replaceAll(string str, const string& src, const string& dest) {
    auto start_pos = 0;
    while((start_pos = str.find(src, start_pos)) != string::npos) {
        str.replace(start_pos, src.length(), dest);
        start_pos += dest.length(); // Handles case where 'dest' is a substring of 'src'
    }
    return str;
}

// Sample Problem: LeetCode 1108