C++ simple string formating

string_format.cpp

/*
 *           DO WHAT THE F*** YOU WANT TO PUBLIC LICENSE
 *                   Version 2, December 2004
 *
 * Copyright (C) 2013- ZwodahS(ericnjf@gmail.com)
 * zwodahs.github.io
 *
 * Everyone is permitted to copy and distribute verbatim or modified
 * copies of this license document, and changing it is allowed as long
 * as the name is changed.
 *
 *           DO WHAT THE F*** YOU WANT TO PUBLIC LICENSE
 *   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
 *
 *  0. You just DO WHAT THE F*** YOU WANT TO.
 *
 * This program is free software. It comes without any warranty, to
 * the extent permitted by applicable law. You can redistribute it
 * and/or modify it under the terms of the Do What The Fuck You Want
 * To Public License, Version 2, as published by Sam Hocevar. See
 * http://sam.zoy.org/wtfpl/COPYING for more details.
 * 
 * Or just consider this as public domain.
 */

/**
 * Code extracted from zframework at github.com/ZwodahS/zframework,
 */

/**
 * Usage :
 *
 *  (format("Hello %s") % world).str
 *  (format("%i + %i is %i) % 3 % 5 % 8).str
 *  (format("Hello Wo%cld) % 'r').str
 *
 * This is unoptimized, and boost should be used if possible.
 * Just throw this into your project, put it into a namespace if you, or modify if you see fit.
 * Let me know if you implement the operator for other type so I can update this gist.
 * 
 * The most updated version will be in my personal codebase in the link above, but I will update this
 * as much as possible.
 */

//////////////////// Header
class Format
{
public:
    Format(const std::string& str);

    Format& operator%(int i);
    Format& operator%(char c);
    Format& operator%(const std::string& str);

    std::string str;
};

Format format(const std::string& str);

//////////////////// Source
std::string& replaceString(std::string& newString, const std::string& searchString, const std::string& replaceString)
{
    auto index = newString.find(searchString);
    if(index != std::string::npos)
    {
        newString.replace(index, searchString.size(), replaceString);
    }
    return newString;
}

Format::Format(const std::string& str)
    : str(str)
{
}

Format format(const std::string& str)
{
    return Format(str);
}

Format& Format::operator%(int i)
{
    std::string s = intToString(i);
    replaceString(str, "%i", s);
    return *this;
}

Format& Format::operator%(char c)
{
    std::string s = charToString(c);
    replaceString(str, "%c", s);
    return *this;
}

Format& Format::operator%(const std::string& s)
{
    replaceString(str, "%s", s);
    return *this;
}