C++ source files conventionally use one of the suffixes ‘ .C ’, ‘ .cc ’, ‘ .cpp ’, ‘ .CPP ’, ‘ .c++ ’, ‘ .cp ’, or ‘ .cxx ’; C++ header files often use ‘ .hh ’, ‘ .hpp ’, ‘ .H ’, or (for shared template code) ‘ .tcc ’; and preprocessed C++ files use the suffix ‘ .ii ’. GCC recognizes files with these names and compiles them as C++ programs even if you call the compiler the same way as for compiling C programs (usually with the name gcc ).
However, the use of gcc does not add the C++ library. g++ is a program that calls GCC and automatically specifies linking against the C++ library. It treats ‘ .c ’, ‘ .h ’ and ‘ .i ’ files as C++ source files instead of C source files unless -x is used. This program is also useful when precompiling a C header file with a ‘ .h ’ extension for use in C++ compilations. On many systems, g++ is also installed with the name c++ .
When you compile C++ programs, you may specify many of the same command-line options that you use for compiling programs in any language; or command-line options meaningful for C and related languages; or options that are meaningful only for C++ programs. See Options Controlling C Dialect , for explanations of options for languages related to C. See Options Controlling C++ Dialect , for explanations of options that are meaningful only for C++ programs.