StreamFormat

A C++ format IO library, based on standard streams.

Documents

For whole documents, see here.

Brief Usage

Print

The usage of print function is like .NET Console.Write:

sf::print("Hello, {0}!\n", "world");            //Hello, world!
sf::print("Meaning of the life: {0}.\n", 42);   //Meaning of the life: 42.
sf::print("{0:x8,s}\n", 4276215469);            //0xfee1dead

And you can write it like Python:

sf::print("The big {} {} ", "brown", "fox");
//If you don't write the index, it will increase automatically.
sf::print("{2} over the {0} {}.\n", "lazy", "dog", "jumps");

If the index is larger than the size of the arguments, it won't be formatted:

sf::print("{0}{10000}{0}\n", "123");//123{10000}123

Additionally, you can print to other streams:

sf::print(std::clog, "{0}:{1}", 11, 59);
std::ostringstream oss;
sf::print(oss, "This message is printed.\n") << "And this is shifted." << endl;

println is a similar function, which will << std::endl after print. As std::endl will flush the stream, println("...") is a little different from print("...\n").

print returns the stream object you have just printed, while sprint returns a string:

std::string s = sf::sprint("{0}{{{1}}}{0}", "123", "321");//123{321}123

Scan

scan function is a bit like print, and actually they share most of the codes:

int a, b;
//Input: 123 456
sf::scan("{0}{1}", a, b);
//The following one is OK:
sf::scan("{0} {1}", a, b);
// Now output:
sf::print("a = {0}, b = {1}\n", a, b);//a = 123, b = 456

std::istringstream iss("HTTP/1.1");
double ver = sf::scan<double>(iss, "HTTP/{}");
sf::print("The HTTP version: {0:f1}", ver);//The HTTP version: 1.1

It is an well-defined behavior to pass an rvalue to scan, if and only if the type of the argument is MoveConstructible.

sscan returns an index from which the part of the string that wasn't scanned starts:

std::string str = "123 abc !!!";
int i; std::string s;
std::string ret = str.substr(sf::sscan(str, "{0}{1}", i, s));//ret == " !!!"

Colors

make_color_arg function helps you to wrap an argument with specified foreground color, background color and font style:

sf::print("{0}, {1}!\n", sf::make_color_arg("Hello", yellow), sf::make_color_arg("world", bright_cyan, blue, underline));