Order of type conversions

[Richard Hartman]

We have an 16-bit signed int, with value of -1.
If it gets cast to a 32 bit unsigned int, does it go:

a) convert to 16 bit unsigned (0xFFFF)
b) convert to 32 bit unsigned (0x0000FFFF)

or

a) convert to 32 bit signed (-1)
b) convert to 32 bit unsigned (0xFFFFFFFF)

and is this order fixed, or undefined (basically left up to the compiler)?

[bartekltg]

4.7 Integral conversions [conv.integral]

2 If the destination type is unsigned, the resulting value is the
least unsigned integer congruent to the source integer (modulo 2
n where n is the number of bits used to represent the unsigned type).

So 0xFFFFFFFF.

bartekltg