Type Alias IsNumeric<T, $O>

IsNumeric: $Special<
    T,
    $MergeOptions<
        $O,
        { $else: IsNumeric.$<T, $O>; $then: $ResolveBranch<$O, [$Else]> },
    >,
>

Is T numeric.

type R = IsNumeric<1> // true
type R = IsNumeric<1.1> // true

type R = IsNumeric<string> // false
type R = IsNumeric<unknown> // false