u-num-it

A simple procedural macros for matching typenum::consts in a given range or array.

Helps you to write

let x:isize = 3;

u_num_it!(-5..5, match x {
    N => {
        NumType::new()
    },
    False => {
        NumType::new()
    },
    P => {
        NumType::new()
    }
})

or with an array of arbitrary numbers:

let x:isize = 8;

u_num_it!([1, 2, 8, 22], match x {
    P => {
        NumType::new()
    },
    _ => panic!()
})

instead of

let x = 3;
match x {
    -5 => {
        typenum::consts::N5::new();
    }
    -4 => {
        typenum::consts::N4::new();
    }
    -3 => {
        typenum::consts::N3::new();
    }
    -2 => {
        typenum::consts::N2::new();
    }
    -1 => {
        typenum::consts::N1::new();
    }
    0 => {
        typenum::consts::False::new();
    }
    1 => {
        typenum::consts::P1::new();
    }
    2 => {
        typenum::consts::P2::new();
    }
    3 => {
        typenum::consts::P3::new();
    }
    4 => {
        typenum::consts::P4::new();
    }
    i => {
        panic!()
    }
}

NumType is available inside each match arm:

u_num_it!(-5..5, match x {
    N => {
        NumType::new()
    },
    False => {
        NumType::new()
    },
    P => {
        // NumType is typenum::consts::P3 when x is 3
        let val: i32 = NumType::to_int();
        val
    }
})