This small library is intended as a fast c++ prototyping tool in cases where something like .NET String.Format or Boost.Locale's format is required, one doesn't need performance, doesn't want to use any large library and doesn't need fancy format specifiers.

Note that, unlike in String.Format or python's format, Boost.Locale formatting language starts the placeholders at 1. Hence, the configurability of fakeformat.

For a fast, but not header-only alternative, check out fmt or cppformat. Others, and most definitely, many more: flossy/c++14, fmt11/c++11,

Just include fakeformat.hpp

The premake4-generated makefiles for Visual Studio 2012 and gnu make can be found in the Build folder for testing purposes.

You can try it out by cloning this ideone code.

Usage is extermely simple in case some prerequisites are met:

• you use STL for which there are default implementations and configurations
• the input parameters are ofstream-streamable
• you use single-byte character set

in terms of a test:

REQUIRE(ff::format("{2}ff{1}").with('a').also_with(7).now()=="7ffa");

unlike the typical c++ string format libraries, fakeformat evaluates the parameters eagerly and saves them temporarily as strings. This allows for a split definition of parameters:

  auto f=ff::format("ff{1}");
	REQUIRE(f.now()=="ff{1}");
	f.with(42);
	f.with(13);
	REQUIRE(f.now()=="ff42");

Unused parameters are ok.

If you need a slight modification of the language, a configuration is no big deal:

struct test_config {
	static const char scope_begin='[';
	static const char scope_end=']';
	static const char separator=',';
	static const char equals='=';
	static const size_t index_begin=0;
	static bool string_to_key(std::string const& to_parse,int& res) {
		... parsing
		if (parsed...)
			return true;
		return false;
	}
};
//...
REQUIRE(ff::formatter<test_config>("[1][0]").with('a').also_with('b').now()=="ba");

The function string_to_key is used for parsing integers from strings. It is currently safe, but very inefficient. Feel free to modify that one. Check out an article on converting strings to integers.

Some format modifiers similar to Boost.Locale are supported:

• num or number with parameters:
• hex
• oct
• sci or scientific
• fix or fixed
• width or w
• number parameter required
• left
• right
• precision
• number parameter required
• fill
• a single character is allowed. Literal } is not supported yet

For the rest of the API, check out the tests.

Currently tested (Win32 and x64) with Visual Studio 2012 Express, and 32 bit in gcc, but should be no problem to test and fix on other compilers and platforms. A premake4 script should help with that task.

Testing is done using Catch.

Check out the blog post

Copyright 2013, Dmitry Ledentsov MIT License: https://www.opensource.org/licenses/mit-license.php