fmt

{fmt} is an open-source formatting library providing a fast and safe alternative to C stdio and C++ iostreams. The format API is similar in spirit to the C printf family of function but is safer, simpler and several times faster than common standard library implementations. The format string syntax is similar to the one used by str.format in Python. The library is fully type safe, automatic memory management prevents buffer overflow, errors in format strings are reported using exceptions or at compile time. The library produces compact per-call compiled code. The library is highly portable and relies only on a small set of C++11 features, like variadic templates, type traits, rvalue references, decltype, trailing return, types, deleted functions, alias templates. These are available in GCC 4.8, Clang 3.0, MSVC 19.0 (2015) and more recent compiler version. For older compilers use {fmt} version 4.x which is maintained and only requires C++98.