|Standard Template Library|
|Standard C Library|
- In C++11 only
Everything inside C++'s standard library is kept in the std:: namespace.
Old compilers may include headers with a .h suffix (e.g. the non-standard <iostream.h> vs. the standard <iostream>) instead of the standard headers. These names were common before the standardization of C++ and some compilers still include these headers for backwards compatibility. Rather than using the std:: namespace, these older headers pollute the global namespace and may otherwise only implement the standard in a limited way.
|Non-standard but somewhat common C++ libraries|
- Streams based on FILE* from stdio.h.
- Precursor to iostream. Old stream library mostly included for backwards compatibility even with old compilers.
- Uses char* whereas sstream uses string. Prefer the standard library sstream.