15 releases (3 stable)
1.0.2 | Feb 8, 2023 |
---|---|
1.0.0 | Feb 24, 2022 |
0.6.0 | Mar 3, 2021 |
0.5.0 | Jul 21, 2020 |
0.2.3 | Jun 19, 2017 |
#422 in Rust patterns
15,040 downloads per month
Used in 37 crates
(7 directly)
6KB
Newtype Variant Conversions
Rust macro crate to automatically generate conversions from variant types into the target enum.
This crate requires Rust 1.45 or above to compile on stable.
Examples
use from_variants::FromVariants;
#[derive(Debug, Clone, PartialEq, Eq, FromVariants)]
pub enum Lorem {
Str(String),
Num(u16),
}
fn main() {
assert_eq!(Lorem::Num(10), Lorem::from(10));
}
You can skip variants to avoid type collisions:
use from_variants::FromVariants;
#[derive(Debug, Clone, PartialEq, Eq, FromVariants)]
pub enum Ipsum {
Hello(String),
#[from_variants(skip)]
Goodbye(String),
}
fn main() {
assert_eq!(Ipsum::Hello("John".to_string()), Ipsum::from("John".to_string()));
}
Features
- Variant opt-out: To skip a variant, add
#[from_variants(skip)]
to that variant. - Conversion opt-in: Use
#[from_variants(into)]
on an enum or variant to generate conversions that will automatically convert - for example, accepting a&str
for aString
variant. This must be used sparingly to avoid generating conflicting impls. - no_std support: Generated conversions do not depend on the standard library.
Dependencies
~2MB
~43K SLoC