boehm::ffi::GC_get_unmapped_bytes
pub extern fn GC_get_unmapped_bytes() -> size_t
pub extern fn GC_get_unmapped_bytes() -> size_t
                Prefix searches with a type followed by a colon (e.g.
                fn:) to restrict the search to a given type.
            
                Accepted types are: fn, mod,
                struct (or str), enum,
                trait, typedef (or
                tdef).