Feature Request: Remove the string constraint from IsNever

[krisdages]

Fiddled around with this one for a while to try and find something that worked, pretty annoying!
Sure wish they would build something like these predicates into the language.

But I think I found a solution. I haven't tested this with keyofStringsOnly turned off, since it's still on in my project, but strangely, keyof never === keyof any === string.

export declare type IsNever<T> = keyof any extends keyof T ? If<IsAny<T>, False, True> : False;

//Examples
type IsNever_1 = IsNever<1>; //False
type IsNever_string = IsNever<string>; //False
type IsNever_null = IsNever<null>; //False
type IsNever_undefined = IsNever<undefined>; //False
type IsNever_void = IsNever<void>; //False
type IsNever_any = IsNever<any>; //False
type IsNever_never = IsNever<never>; //True
type IsNever_any_and_never = IsNever<any & never>; //True
type IsNever_any_or_never = IsNever<any | never>; //False