The type to cast to
If Hook defines hookOpCast, the call immediately returns hook.hookOpCast!U(get). Otherwise, casting to bool yields get != 0 and casting to another integral that can represent all values of T returns get promoted to U.
assert(cast(uint) checked(42) == 42); assert(cast(uint) checked!WithNaN(-42) == uint.max);
Casting operator to integral, bool, or floating point type.
If a cast to a floating-point type is requested and Hook defines onBadCast, the cast is verified by ensuring get == cast(T) U(get). If that is not true, hook.onBadCast!U(get) is returned.
If a cast to an integral type is requested and Hook defines onBadCast, the cast is verified by ensuring get and cast(U) get are the same arithmetic number. (Note that int(-1) and uint(1) are different values arithmetically although they have the same bitwise representation and compare equal by language rules.) If the numbers are not arithmetically equal, hook.onBadCast!U(get) is returned.