boost字符串处理函数format的用法

    char text[]="hello";    
    bool is_all_lower = boost::algorithm::all(text, is_lower());

    char output[128];
    sprintf(output, "<%s> %s in the lower case", text, (is_all_lower? "is": "is not"));

    stringstream output;
    output << "<" << text << "> "
        << (is_all_lower)? "is": "is not") 
        << " in the lower case";

    boost::format fmt = boost::format("<%s> %s in the lower case") % text % (is_all_lower? "is": "is not");
    string output = fmt.str();

    boost::format fmt = boost::format("<%1%> %2% in the lower case") % text % (is_all_lower? "is": "is not");
    cout << fmt << endl;

    //传统c语言风格
    cout << boost::format("\n\n%s" 
            "%1t 十进制 = [%d]\n" 
            "%1t 格式化的十进制 = [%5d]\n" 
            "%1t 格式化十进制，前补'0' = [%05d]\n" 
            "%1t 十六进制 = [%x]\n" 
            "%1t 八进制 = [%o]\n" 
            "%1t 浮点 = [%f]\n" 
            "%1t 格式化的浮点 = [%3.3f]\n" 
            "%1t 科学计数 = [%e]\n" 
            ) % "example :\n" % 15 % 15 % 15 % 15 % 15 % 15.01 % 15.01 % 15.01 << endl; 

    //.net的风格
    cout << boost::format("%1%" 
            "%1t 十进制 = [%2$d]\n" 
            "%1t 格式化的十进制 = [%2$5d]\n" 
            "%1t 格式化十进制，前补'0' = [%2$05d]\n" 
            "%1t 十六进制 = [%2$x]\n" 
            "%1t 八进制 = [%2$o]\n" 
            "%1t 浮点 = [%3$f]\n" 
            "%1t 格式化的浮点 = [%3$3.3f]\n" 
            "%1t 科学计数 = [%3$e]\n" 
            ) % "example :\n" % 15 % 15.01 << endl;

    try
    {
        boost::format("<%3");
    }
    catch(std::exception& err)
    {
        cout << err.what() << endl;
    }

    boost::format fmt = boost::format("<%3%> %2% in the lower case") % text % (is_all_lower? "is": "is not");
    try
    {
        cout << fmt << endl;
    }
    catch(std::exception& err)
    {
        cout << err.what() << endl;
    }

string string_fromat(const char* format, …)

    template<class TFirst>
    void string_format(boost::format& fmt, TFirst&& first)
    {
        fmt % first;
    }

    template<class TFirst, class... TOther>
    void string_format(boost::format& fmt, TFirst&& first, TOther&&... other)
    {
        fmt % first;
        string_format(fmt, other...);
    }

    template<class TFirst, class... TOther>
    string string_format(const char* format, TFirst&& first, TOther&&... other)
    {
        boost::format fmt(format);
        string_format(fmt, first, other...);
        return fmt.str();
    }

auto output = string_format("<%1%> %2% in the lower case", text, (is_all_lower? "is": "is not"));