Function notmuch_sys::notmuch_message_add_tag

pub unsafe extern "C" fn notmuch_message_add_tag(
    message: *mut notmuch_message_t, 
    tag: *const c_char
) -> notmuch_status_t

Add a tag to the given message.

Return value:

• notmuch_status_t::SUCCESS: Tag successfully added to message

• notmuch_status_t::NULL_POINTER: The 'tag' argument is NULL

• notmuch_status_t::TAG_TOO_LONG: The length of 'tag' is too long (exceeds TAG_MAX)

• notmuch_status_t::READ_ONLY_DATABASE: Database was opened in read-only mode so message cannot be modified.