Type Alias typenum::generic_const_mappings::U
source · pub type U<const N: usize> = <Const<N> as ToUInt>::Output;
Available on crate feature
const-generics
only.Expand description
The main mapping from a generic const: usize
to a UInt
: U<N>
is expected to work like UN
.
- It requires the
const-generics
crate feature to be enabled.
§Example
use typenum::*;
assert_type_eq!(U<42>, U42);
This can even be used in a generic const N: usize
context, provided the
genericity is guarded by a where
clause:
use typenum::*;
struct MyStruct<const N: usize>;
trait MyTrait { type AssocType; }
impl<const N: usize> MyTrait
for MyStruct<N>
where
Const<N> : ToUInt,
{
type AssocType = U<N>;
}
assert_type_eq!(<MyStruct<42> as MyTrait>::AssocType, U42);