Function NSMapInsertIfAbsent 

pub unsafe extern "C-unwind" fn NSMapInsertIfAbsent(
    table: &NSMapTable,
    key: *const c_void,
    value: *const c_void,
) -> *mut c_void

Available on crate feature NSMapTable only.

Safety

• table generic should be of the correct type.
• key must be a valid pointer or null.
• value must be a valid pointer or null.