Macro glib::glib_boxed_wrapper

macro_rules! glib_boxed_wrapper {
    ([$($attr:meta)*] $name:ident, $ffi_name:path, @copy $copy_arg:ident $copy_expr:expr,
     @free $free_arg:ident $free_expr:expr) => { ... };
}

Wrapper implementations for Boxed types. See glib_wrapper!.