The C99 standard introduces several new library features of interest to programmers, including:
Some features similar to extensions to the C90 standard libraries offered in UNIX standard libraries, for example, the
snprintffamily of functions.
Some entirely new library features, for example, the standardized floating-point environment offered in
New libraries, and new macros and functions for existing C90 libraries.
A selection of new features in C99 that might be of interest to developers using them for the first time are documented.
C90 is compatible with Standard C++ in the sense that the language specified by the standard is a subset of C++, except for a few special cases. New features in the C99 standard mean that C99 is no longer compatible with C++ in this sense.
Many library features that are new to C99 are available in
C90 and C++. Some require macros such as
be defined before the