Function hints_ 

fn hints_(
    acc: &mut Vec<InlayHint>,
    ctx: &mut InlayHintCtx,
    FamousDefs: &FamousDefs<'_, '_>,
    config: &InlayHintsConfig<'_>,
    params: impl Iterator<Item = (Option<Name>, Type)>,
    generic_param_list: Option<GenericParamList>,
    ret_type: Option<RetType>,
    self_param: Option<SelfParam>,
    on_missing_gpl: impl FnOnce(&mut Vec<InlayHint>, &[SmolStr]),
    is_trivial: bool,
) -> Option<()>