explicit-discriminant

此crate强制执行枚举的显式判别式。

use explicit_discriminant::ExplicitDiscriminant;

#[derive(ExplicitDiscriminant)]
enum MyEnum {
    One = 1,
    Two = 2,
    Three, // will not compile
    Four = 4
}

您还可以可选地添加模式，强制执行允许的判别式值。

use explicit_discriminant::ExplicitDiscriminant;

#[derive(ExplicitDiscriminant)]
#[pattern(2..=3 | 12..)]
#[pattern(9 | ..-3)]
enum MyEnum {
    MinusFour = -4,
    One = 1, // error here, since not in any of the patterns
    Two = 2,
    Three = 3, 
    Nine = 9,
    Ten = 10, // error here, since not in any of the patterns
    Twelve = 12,
    OneHundred = 100,
}