Trait funcmap::FuncMarker
source · pub trait FuncMarker<P>: Sealed<P> { }
Expand description
Marker trait for marker types specifying what to map over
This is only implemented by the marker types TypeParam<N>
and is used to
restrict the choice of types for the P
type parameter of
FuncMap<A, B, P>
and TryFuncMap<A, B, P>
.
Note that FuncMarker<P>
is itself generic over P
and for all
implementations, the type parameter P
is the implementing type itself.
This way, from Q: FuncMarker<P>
it can be inferred that Q == P
, which is
used in the FuncMap::func_map_over
and TryFuncMap::try_func_map_over
methods.
This trait is sealed and cannot be implemented outside of funcmap
.