This is your safest bet:
template Cast(T: typedesc, value: untyped): untyped =
cast[T](value)
echo Cast(int, 3)
Run
To explain the template parameter types, `typedesc` (or just `type` is enough
if you're on 0.19) matches type descriptors, so things like `int`, `Exception`,
`seq`, `Slice[int]` and whatnot. `untyped` matches any AST expression and no
type checking is performed on it, so you can do things like:
template foo(ex: untyped) =
var a {.inject.} = 3 # {.inject.} passes the variable `a` to `ex`
echo ex
foo(a * 4) # 12
Run
On the other hand, templates can also have generics, so you can do:
template Cast[T](_: typedesc[T], value: untyped): T =
cast[T](value)
echo Cast(int, 3)
Run
Like before, if you're on 0.19, you can replace `typedesc[T]` with `type T`.
