# Automatically generated; edit in Sphinx source code, not here.
global x: optional<uint64>;  # Unset.
global b1: bool = x;         # False.
global b2 = cast<bool>(x);   # False.

if ( x )
    print "'x' was set";     # Never runs.
if ( ! x )
    print "'x' was unset";   # Always runs.