Macro ibc::downcast

macro_rules! downcast {
    ( $e1:expr => $p1:path, $( $e:expr => $p:path ),+ $(,)? ) => { ... };
    ($e:expr => $p:path) => { ... };
    () => { ... };
}

Downcast the given arguments to the associated enum variant.

Note

Only works for enums whose variants only hold a single value.

Example

use ibc::downcast;

enum Foo {
    Bar(u32),
    Baz(bool),
}

let bar = Foo::Bar(42);
let baz = Foo::Baz(true);

if let Some(value) = downcast!(bar => Foo::Bar) {
    println!("value is a u32: {}", value);
}

if let Some(value) = downcast!(baz => Foo::Baz) {
    println!("value is a bool: {}", value);
}

if let Some((a, b)) = downcast!(bar => Foo::Bar, baz => Foo::Baz) {
    println!("a is a u32: {}", a);
    println!("b is a bool: {}", b);
}