Function gtk4_sys::gtk_im_context_get_surrounding_with_selection

pub unsafe extern "C" fn gtk_im_context_get_surrounding_with_selection(
    context: *mut GtkIMContext, 
    text: *mut *mut c_char, 
    cursor_index: *mut c_int, 
    anchor_index: *mut c_int
) -> gboolean

This is supported on crate feature v4_2 only.