Type Definition melib::backends::notmuch::bindings::notmuch_message_properties_key

type notmuch_message_properties_key = unsafe extern "C" fn(properties: *mut notmuch_message_properties_t) -> *const c_char;

Return the key from the current (key,value) pair.

this could be useful if iterating for a prefix

@since libnotmuch 4.4 (notmuch 0.23)