2 releases
0.1.1 | Jul 16, 2023 |
---|---|
0.1.0 | Jul 16, 2023 |
#1360 in Rust patterns
Used in sync_stream
8KB
153 lines
Mixed Array
Construct arrays of mixed types. Generic enums are created for up to 12 unique types. A macro to generate an array using the correct size macro is provided.
Usage
- Include in the
Cargo.toml
file:
[dependencies]
mixed_array = "0.1.0"
- Import and use the
mixed_array
macro to create an array of items
use mixed_array::mixed_array;
use std::cmp::Ordering;
// define a struct with a generic so the generated types are different as a demo
#[derive(Clone, Debug)]
struct Item<T> {
id: u32,
value: T,
}
impl<T> Eq for Item<T> {}
//implement ordering for our item for any T
impl<T, B> PartialEq<Item<B>> for Item<T> {
fn eq(&self, other: &Item<B>) -> bool {
self.id == other.id
}
}
impl<T, B> PartialOrd<Item<B>> for Item<T> {
fn partial_cmp(&self, other: &Item<B>) -> Option<Ordering> {
self.id.partial_cmp(&other.id)
}
}
impl<T> Ord for Item<T> {
fn cmp(&self, other: &Self) -> Ordering {
self.id.cmp(&other.id)
}
}
fn main() {
//can now create an array of different types
let items = mixed_array![
Item::<&str> {
id: 100,
value: "blah",
},
Item::<u32> {
id: 200,
value: 123,
},
Item::<f32> {
id: 300,
value: 9.3,
},
];
dbg!(items.into_iter().min());
}
Alternatives
- Frunk - HList - Provides a `hlist`` macro to construct a recursive custom data type used for storing different types (replaces using an array), easy conversion to tuples.
Dependencies
~225–670KB
~16K SLoC