About this document

This document describes the syntax, semantics, and IBM(R) implementation of the C and C++ programming languages. Although the XL C and XL C++ compilers conform to the specifications maintained by the ISO standards for the C and C++ programming languages, the compilers also incorporate many extensions to the core languages. These extensions have been implemented with the aims of enhancing usability in specific operating environments, assuring compatibility with other compilers, and supporting new hardware capabilities. For example, on UNIX(R) platforms, many language constructs have been added for compatibility with the GNU Compiler Collection (GCC), to maximize portability between the two development environments.