Trait Is

pub trait Is
where
    Self: Sealed + From<IsType<Self>> + Into<IsType<Self>> + AsRef<IsType<Self>> + AsMut<IsType<Self>>,
{
    type Type;
}

Marker trait for type identity

This trait is used as part of the AnyKind trait pattern. It represents the concept of type identity, because all implementors have <Self as Is>::Type == Self. When used as a trait bound with a specific type, it guarantees that the corresponding type parameter is exactly the specific type. Stated differently, it guarantees that T == Specific in the following example.

where T: Is<Type = Specific>

Moreover, the super traits guarantee that any instance of or reference to a type T can be converted into the Specific type.

fn example<T>(mut any: T)
where
    T: Is<Type = Specific>,
{
    let specific_mut: &mut Specific = any.as_mut();
    let specific_ref: &Specific = any.as_ref();
    let specific: Specific = any.into();
}

Required Associated Types

type Type

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T> Is for T

where T: Sealed + AsRef<T> + AsMut<T>,

type Type = T