Add `When` type family
Does a type family like When
from here belong somewhere in Data.Types.*
type
When :: Bool -> Constraint -> Constraint
type family
When cond cls where
When True cls = cls
When False cls = ()
like when.
Trac metadata
Trac field | Value |
---|---|
Version | 8.1 |
Type | FeatureRequest |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Core Libraries |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | ekmett |
Operating system | |
Architecture |