Derive Macro num_enum_derive::TryFromPrimitive [−][src]
#[derive(TryFromPrimitive)] { // Attributes available to this derive: #[num_enum] }
Implements TryFrom<Primitive>
for a #[repr(Primitive)] enum
.
Attempting to turn a primitive into an enum with try_from
.
use num_enum::TryFromPrimitive; use std::convert::TryFrom; #[derive(Debug, Eq, PartialEq, TryFromPrimitive)] #[repr(u8)] enum Number { Zero, One, } fn main() { let zero = Number::try_from(0u8); assert_eq!(zero, Ok(Number::Zero)); let three = Number::try_from(3u8); assert_eq!( three.unwrap_err().to_string(), "No discriminant in enum `Number` matches the value `3`", ); }