Ruby 1.9.2 リファレンスマニュアル > ライブラリ一覧 > mkmfライブラリ > Kernelモジュール > have_type (private)

instance method Kernel#have_type

have_type(type, headers = nil, opt = "", &b) [added by mkmf]

Returns whether or not the static type +type+ is defined. You may optionally pass additional +headers+ to check against in addition to the common header files.

You may also pass additional flags to +opt+ which are then passed along to the compiler.

If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with 'HAVE_TYPE_'.

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