def raw_description(t: object) -> str:
            """describe a raw type (ie, one that is not a ContainerTypeInfo)."""
            if isinstance(t, list):
                if t:
                    return f"array[{' | '.join(sorted(mesonlib.OrderedSet(type(v).__name__ for v in t)))}]"
                return 'array[]'
            elif isinstance(t, dict):
                if t:
                    return f"dict[{' | '.join(sorted(mesonlib.OrderedSet(type(v).__name__ for v in t.values())))}]"
                return 'dict[]'
            return type(t).__name__
describe a raw type (ie, one that is not a ContainerTypeInfo).
mesonbuild/interpreterbase/decorators.py