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".

Implementations on Foreign Types

impl DowncastFrom<Group> for ()

fn downcast_from(self_: Group) -> 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<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<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<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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> 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> DowncastFrom<A> for Box<B>

where B: DowncastFrom<A>,

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

where Self: Sized,

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<Value> for (A, B)

where A: DowncastFrom<Value>, B: 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> DowncastFrom<Value> for (A,)

where A: DowncastFrom<Value>,

fn downcast_from(self_: Value) -> 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 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 Decimal

impl DowncastFrom<Value> for Enum

impl DowncastFrom<Value> for Group

impl DowncastFrom<Value> for IpAddr

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 Value

impl DowncastFrom<Value> for Webpage<'static>

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

where T: DowncastFrom<Value> + Data,