enum_traits
A library with traits and accompanying procedural macros that adds functionality to enums.
Provides traits and "derives" for enum items in the Rust programming language:
Derives
- EnumIndex
- EnumFromIndex
- EnumToIndex
- EnumLen
- EnumEnds
- EnumIter
- EnumIterator
Traits
- Index
- FromIndex
- ToIndex
- Len
- Ends
- Discriminant
- Iterable
Examples
#![feature(associated_consts,proc_macro)]
#[macro_use]extern crate enum_traits_macros;
extern crate enum_traits;
use enum_traits::*;
fn f1(){
#[derive(Debug,EnumIndex,EnumToIndex,EnumLen)]
enum Enum<'t,T: 't>{
VariantA(&'t T),
VariantB(T),
VariantC(T,T,T),
VariantD{d: i32},
VariantE{a: i8,b: i16,c: i32},
VariantF,
}
assert_eq!(Enum::VariantB("OK").into_index(),1);
assert_eq!(Enum::<'static,&'static str>::LEN,6);
}
fn f2(){
#[derive(Debug,EnumIndex,EnumFromIndex,EnumToIndex,EnumLen,EnumIter,EnumIterator,EnumDiscriminant,EnumEnds)]
enum Enum{
VariantA = 10,
VariantB = 20,
VariantC = 30,
}
//From EnumToIndex
assert_eq!(Enum::VariantB.into_index(),1);
//From EnumLen
assert_eq!(Enum::LEN,3);
//From EnumFromIndex
assert!(match Enum::from_index(1){
Some(Enum::VariantB) => true,
_ => false
});
//From EnumDiscriminant
assert!(match Enum::from_discriminant(20){
Some(Enum::VariantB) => true,
_ => false
});
//From EnumEnds
assert!(match Enum::first(){
Enum::VariantA => true,
_ => false
});
//From EnumEnds
assert!(match <Enum as Ends>::last(){
Enum::VariantC => true,
_ => false
});
//From EnumIter
assert!(match Enum::variants().next(){
Some(Enum::VariantA) => true,
_ => false
});
//From EnumIterator
assert!(match Enum::VariantA.next(){
Some(Enum::VariantB) => true,
_ => false
});
}
See the tests for more examples. See the docs, the tests or the source code for more information.