Jonathan M Davis wrote:
On 2011-05-15 03:50, Joel Christensen wrote:
Looks like enum's are tighter (eg. 'enum last = media[ $ - 1 ];' doesn't
work now). It was working in 52. I had heard it might be relaxed, not
tightened. I get the error, 'cannot be read at compile time'.
Also immutable imstr = "test"; printf( toStringz( imstr ) ); wasn't
working at first, but works now for some reason.
Good to have an update though.
A lot of CTFE stuff was rewritten. What all of the implications of that are, I
don't know, but according to Don (who did the rewrite), there are cases which
compiled before but didn't generate correct code. I don't know if there were
any cases which compiled which were supposed to be illegal.
There are VERY MANY cases which compiled before, which were supposed to
be illegal. The compiler used to accept a variable where it needed a
compile-time constant!
> Regardless,
because there was a major rewrite for CTFE, the risk of CTFE bugs or
behavioral changes is higher than is the case for most releases.
To clarify:
Two massive fixes were made, which are independent of each other:
(1) CONSTANT FOLDING: any case where a compile-time value is required
now MUST be a compile-time value. If a compile-time value is not
required, there is no attempt to interpret it. This fixed many
accepts-invalid bugs.
(2) CTFE: array literals no longer use copy-on-write (which gave totally
wrong semantics). This fixed many wrong-code bugs.
Fixing (2) also allowed a huge number of CTFE bugs to be fixed.
This particular example is a consequence of (1), and has nothing to do
with the CTFE changes.
