Crates.io | match_cast |
lib.rs | match_cast |
version | 0.1.2 |
source | src |
created_at | 2016-09-23 13:16:06.652004 |
updated_at | 2016-09-23 13:52:31.331171 |
description | Macro to match through Any types |
homepage | |
repository | https://github.com/DenisKolodin/match_cast |
max_upload_size | |
id | 6596 |
size | 3,212 |
This is a minimal crate which implements match through different types.
Usage:
#[macro_use]
extern crate match_cast;
use std::panic;
fn main() {
let res = panic::catch_unwind(|| {
panic!("Oh no!");
});
let any = res.unwrap_err();
let result = match_cast!( any {
val as Option<u8> => {
format!("Option<u8> = {:?}", val)
},
val as String => {
format!("String = {:?}", val)
},
val as &'static str => {
format!("&'static str = {:?}", val)
},
});
assert_eq!(result.unwrap(), "&'static str = \"Oh no!\"");
}
To use pattern there is match_down
macro:
#[macro_use]
extern crate match_cast;
use std::any::Any;
struct Bar {
x: u8,
}
struct Foo {
x: u8,
}
fn main() {
let any: Box<Any> = Box::new(Foo { x: 45 });
let result = match_down!( any {
Bar { x } => { x },
Foo { x } => { x },
});
assert_eq!(result.unwrap(), 45);
}