Trait DowncastFrom 

pub trait DowncastFrom<T>
where
    T: Downcast<Self>,
    Self: Sized,
{
    // Required method
    fn downcast_from(t: T) -> Result<Self, DowncastError>
       where Self: Sized;
}

This trait lets one downcast a generic type like Value to a specific type like u64.

It exists, rather than for example using TryInto, due to coherence issues with downcasting to foreign types like Option<T>.

Required Methods

fn downcast_from(t: T) -> Result<Self, DowncastError>

where Self: Sized,

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.

Implementations on Foreign Types

impl DowncastFrom<Value> for bool

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for f32

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for f64

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for i8

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for i16

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for i32

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for i64

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for u8

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for u16

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for u32

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for u64

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for ()

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Value> for String

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl DowncastFrom<Group> for ()

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A> DowncastFrom<Value> for (A,)

where A: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A> DowncastFrom<Group> for (A,)

where A: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B> DowncastFrom<Value> for (A, B)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B> DowncastFrom<Group> for (A, B)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B> DowncastFrom<A> for Box<B>

where B: DowncastFrom<A>,

fn downcast_from(t: A) -> Result<Self, DowncastError>

where Self: Sized,

impl<A, B, C> DowncastFrom<Value> for (A, B, C)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C> DowncastFrom<Group> for (A, B, C)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D> DowncastFrom<Value> for (A, B, C, D)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D> DowncastFrom<Group> for (A, B, C, D)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E> DowncastFrom<Value> for (A, B, C, D, E)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E> DowncastFrom<Group> for (A, B, C, D, E)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F> DowncastFrom<Value> for (A, B, C, D, E, F)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F> DowncastFrom<Group> for (A, B, C, D, E, F)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G> DowncastFrom<Value> for (A, B, C, D, E, F, G)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G> DowncastFrom<Group> for (A, B, C, D, E, F, G)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H> DowncastFrom<Value> for (A, B, C, D, E, F, G, H)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H> DowncastFrom<Group> for (A, B, C, D, E, F, G, H)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I> DowncastFrom<Value> for (A, B, C, D, E, F, G, H, I)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I> DowncastFrom<Group> for (A, B, C, D, E, F, G, H, I)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I, J> DowncastFrom<Value> for (A, B, C, D, E, F, G, H, I, J)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>, J: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I, J> DowncastFrom<Group> for (A, B, C, D, E, F, G, H, I, J)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>, J: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I, J, K> DowncastFrom<Value> for (A, B, C, D, E, F, G, H, I, J, K)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>, J: DowncastFrom<Value>, K: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I, J, K> DowncastFrom<Group> for (A, B, C, D, E, F, G, H, I, J, K)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>, J: DowncastFrom<Value>, K: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I, J, K, L> DowncastFrom<Value> for (A, B, C, D, E, F, G, H, I, J, K, L)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>, J: DowncastFrom<Value>, K: DowncastFrom<Value>, L: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<A, B, C, D, E, F, G, H, I, J, K, L> DowncastFrom<Group> for (A, B, C, D, E, F, G, H, I, J, K, L)

where A: DowncastFrom<Value>, B: DowncastFrom<Value>, C: DowncastFrom<Value>, D: DowncastFrom<Value>, E: DowncastFrom<Value>, F: DowncastFrom<Value>, G: DowncastFrom<Value>, H: DowncastFrom<Value>, I: DowncastFrom<Value>, J: DowncastFrom<Value>, K: DowncastFrom<Value>, L: DowncastFrom<Value>,

fn downcast_from(self_: Group) -> Result<Self, DowncastError>

impl<K, V, S> DowncastFrom<Value> for HashMap<K, V, S>

where K: DowncastFrom<Value> + Hash + Eq, V: DowncastFrom<Value>, S: BuildHasher + Default,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for Option<T>

where T: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 0]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 1]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 2]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 3]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 4]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 5]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 6]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 7]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 8]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 9]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 10]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 11]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 12]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 13]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 14]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 15]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 16]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 17]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 18]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 19]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 20]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 21]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 22]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 23]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 24]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 25]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 26]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 27]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 28]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 29]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 30]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 31]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

impl<T> DowncastFrom<Value> for [T; 32]

where T: DowncastFrom<Value> + Data,

fn downcast_from(self_: Value) -> Result<Self, DowncastError>

Implementors

impl DowncastFrom<Value> for Decimal

impl DowncastFrom<Value> for IpAddr

impl DowncastFrom<Value> for Value

impl DowncastFrom<Value> for Bson

impl DowncastFrom<Value> for Date

impl DowncastFrom<Value> for DateTime

impl DowncastFrom<Value> for DateTimeWithoutTimezone

impl DowncastFrom<Value> for DateWithoutTimezone

impl DowncastFrom<Value> for Enum

impl DowncastFrom<Value> for Group

impl DowncastFrom<Value> for Json

impl DowncastFrom<Value> for Time

impl DowncastFrom<Value> for TimeWithoutTimezone

impl DowncastFrom<Value> for Timezone

impl DowncastFrom<Value> for Url

impl DowncastFrom<Value> for Webpage<'static>

impl<T> DowncastFrom<Value> for List<T>

where T: DowncastFrom<Value> + Data,