macro_rules! cmp { ($a:ident < $b:ty) => { ... }; ($a:ty, < $b:ty) => { ... }; ($a:ident == $b:ty) => { ... }; ($a:ty, == $b:ty) => { ... }; ($a:ident > $b:ty) => { ... }; ($a:ty, > $b:ty) => { ... }; ($a:ident <= $b:ty) => { ... }; ($a:ty, <= $b:ty) => { ... }; ($a:ident != $b:ty) => { ... }; ($a:ty, != $b:ty) => { ... }; ($a:ident >= $b:ty) => { ... }; ($a:ty, >= $b:ty) => { ... }; }
👎Deprecated since 1.9.0: use the
op!
macro insteadExpand description
A convenience macro for comparing type numbers. Use op!
instead.
Due to the intricacies of the macro system, if the left-hand operand is more complex than a simple
ident
, you must place a comma between it and the comparison sign.
For example, you can do cmp!(P5 > P3)
or cmp!(typenum::P5, > typenum::P3)
but not
cmp!(typenum::P5 > typenum::P3)
.
The result of this comparison will always be one of True
(aka B1
) or False
(aka B0
).
§Example
#[macro_use] extern crate typenum;
use typenum::consts::*;
use typenum::Bit;
fn main() {
type Result = cmp!(P9 == op!(P1 + P2 * (P2 - N2)));
assert_eq!(Result::to_bool(), true);
}