Type Alias _N<T, $O>

_N<T, $O>: [T] extends [boolean]
    ? [T] extends [true]
        ? $ResolveBranch<T, $O, [$Else]>
        : [T] extends [false]
            ? $ResolveBranch<T, $O, [$Else]>
            : $ResolveBranch<T, $O, [$Then]>
    : $ResolveBranch<T, $O, [$Else]>