Type Definition opensc_sys::element_comparator

type element_comparator = Option<unsafe extern "C" fn(a: *const c_void, b: *const c_void) -> c_int>;

a comparator of elements.

A comparator of elements is a function that: -# receives two references to elements a and b -# returns {<0, 0, >0} if (a > b), (a == b), (a < b) respectively

It is responsibility of the function to handle possible NULL values.