3.3 Compiling C++ Programs
C++ source files conventionally use one of the suffixes ` .C ', ` .cc ', ` .cpp ', ` .CPP ', ` .c++ ', ` .cp ', or ` .cxx '; C++ header files often use ` .hh ' or ` .H '; 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, C++ programs often require class libraries as well as a compiler that understands the C++ language—and under some circumstances, you might want to compile programs or header files from standard input, or otherwise without a suffix that flags them as C++ programs. You might also like to precompile a C header file with a ` .h ' extension to be used in C++ compilations. g++ is a program that calls GCC with the default language set to C++, and automatically specifies linking against the C++ library. 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.