Extensions to C++ to support C99 standard features

The Standard C++ language specification does not include many of the features specified in the C99 language standard. To promote compatibility and portability between C99 and C++, the XL C++ compiler enables many of the C99 features that are supported by the XL C compiler. Since these features extend Standard C++, they are considered extensions to the base language. In this reference, unless the text is marked to indicate that a feature is supported in C or C99 only, C99 features also apply to C++. A complete list of C99 features supported in XL C++ is also provided in Appendix B. The IBM XL C++ language extensions.