have_func

Returns whether or not the function func can be found in the common header files, or within any headers that you provide. If found, a macro is passed as a preprocessor constant to the compiler using the function name, in uppercase, prepended with HAVE_.

To check functions in an additional library, you need to check that library first using have_library(). The func shall be either mere function name or function name with arguments.

For example, if have_func('foo') returned true, then the HAVE_FOO preprocessor macro would be passed to the compiler.