TypeCastError isn't raised when casting scalar value

[Blacksmoke16]

https://play.crystal-lang.org/#/r/a1tf

1.as String

Showing last frame. Use --error-trace for full trace.

error in line 1
Error: can't cast Int32 to String

I would have expected this to work like the example in the API docs, where it actually raises a TypeCastError.

[jhass]

TypeCastError is a runtime error, it happens when resolving a union to a type that doesn't match its actual value at runtime.

You're looking at a compile error here.

Also remember, casting is interpreting the same value (the same bytes) as a different type. Conversion or coercion is producing an equivalent or comparable value in a different type. as does casting only.

Compare https://carc.in/#/r/a1tp

[Blacksmoke16]

Ahh rip, don't mind me 🙈.