Method tuple_context_matches

mypy/checkexpr.py:5260–5271

(self, expr: TupleExpr, ctx: TupleType)

        return remove_instance_last_known_values(out)

    def tuple_context_matches(self, expr: TupleExpr, ctx: TupleType) -> bool:
        ctx_unpack_index = find_unpack_in_list(ctx.items)
        if ctx_unpack_index is None:
            # For fixed tuples accept everything that can possibly match, even if this
            # requires all star items to be empty.
            return len([e for e in expr.items if not isinstance(e, StarExpr)]) <= len(ctx.items)
        # For variadic context, the only easy case is when structure matches exactly.
        # TODO: try using tuple type context in more cases.
        if len([e for e in expr.items if isinstance(e, StarExpr)]) != 1:
            return False
        expr_star_index = next(i for i, lv in enumerate(expr.items) if isinstance(lv, StarExpr))
        return len(expr.items) == len(ctx.items) and ctx_unpack_index == expr_star_index

    def visit_tuple_expr(self, e: TupleExpr) -> Type:
        """Type check a tuple expression."""