Formateur de chaine de caratère std::string à la manière Qt (voir QString)

strformat.cpp

#include "strformat.h"
#include <iomanip>
#include <cassert>

strformat::strformat(const std::string &str) : _str(str), _level(1)
{

}

strformat &strformat::arg(const std::string &str1)
{
    _replace_arg(str1);
    return *this;
}

strformat &strformat::arg(const std::string &str1, const std::string &str2)
{
    _replace_arg(str1);
    _replace_arg(str2);
    return *this;
}

strformat &strformat::arg(const std::string &str1, const std::string &str2, const std::string &str3)
{
    _replace_arg(str1);
    _replace_arg(str2);
    _replace_arg(str3);
    return *this;
}

strformat &strformat::arg(const std::string &str1, const std::string &str2, const std::string &str3, const std::string &str4)
{
    _replace_arg(str1);
    _replace_arg(str2);
    _replace_arg(str3);
    _replace_arg(str4);
    return *this;
}

strformat &strformat::arg(const char *str)
{
    if(str)
        _replace_arg(std::string(str));
    else
        _replace_arg(std::string());
    return *this;
}

strformat &strformat::arg(int value, int base)
{
    _replace_arg(to_string(value, base));
    return *this;
}

strformat &strformat::arg(unsigned int value, int base)
{
    _replace_arg(to_string(value, base));
    return *this;
}

strformat &strformat::arg(long value, int base)
{
    _replace_arg(to_string(value, base));
    return *this;
}

strformat &strformat::arg(unsigned long value, int base)
{
    _replace_arg(to_string(value, base));
    return *this;
}

strformat &strformat::arg(long long value, int base)
{
    _replace_arg(to_string(value, base));
    return *this;
}

strformat &strformat::arg(unsigned long long value, int base)
{
    _replace_arg(to_string(value, base));
    return *this;
}

strformat &strformat::arg(double value, int precision)
{
    std::ostringstream ostr;
    ostr<<std::setprecision(precision)<<value;
    _replace_arg(ostr.str());
    return *this;
}

strformat::operator std::string() const
{
    return _str;
}

void strformat::_replace_arg(const std::string &text)
{
    const std::string num = '%' + to_string(_level++);
    size_t pos;
    while((pos = _str.find(num)) != std::string::npos)
        _str.replace(pos, num.size(), text);
}

strformat.h

#ifndef STRINGTOOLS_H
#define STRINGTOOLS_H

#include <string>
#include <sstream>

/**\brief
*   Permet de formater une chaine de caractère
*   Exemple : std::string str = strformat("valeur: %1 info : %2").arg(12.0).arg("test");
*/
class strformat
{
public:
    strformat(const std::string &str);

    strformat &arg(const std::string &str1);
    strformat &arg(const std::string &str1, const std::string &str2);
    strformat &arg(const std::string &str1, const std::string &str2, const std::string &str3);
    strformat &arg(const std::string &str1, const std::string &str2, const std::string &str3, const std::string &str4);
    strformat &arg(const char *str);

    strformat &arg(int value, int base = 10);
    strformat &arg(unsigned int value, int base = 10);
    strformat &arg(long value, int base = 10);
    strformat &arg(unsigned long value, int base = 10);
    strformat &arg(long long value, int base = 10);
    strformat &arg(unsigned long long value, int base = 10);
    strformat &arg(double value, int precision=15);

    operator std::string() const;

    template <typename T>
    static T from_string(const std::string &text)
    {
        T value;
        std::istringstream istr(text);
        if(text.size() > 2 && text.at(0) == '0' && (text.at(1) == 'x' || text.at(1) == 'X'))
            istr>>std::hex>>value;
        else
            istr>>value;
        return value;
    }

    template <typename T>
    static T from_cstring(const char *text)
    {
        if(text)
            return from_string<T>(text);
        return 0;
    }

    template <typename T>
    static std::string to_string(T value, int base=10)
    {
        std::ostringstream ostr;
        switch(base)
        {
        case 8:
            ostr<<std::oct<<value;
            break;
        case 10:
            ostr<<std::dec<<value;
            break;
        case 16:
            ostr<<std::hex<<value;
            break;
        default:
            ostr<<value;
        }
        return ostr.str();
    }

private:
    void _replace_arg(const std::string &text);

    std::string _str;
    int _level;
};

#endif // STRINGTOOLS_H