On Thu, 23 May 2013 12:09:26 -0400, Don <[email protected]>
wrote:
On Thursday, 23 May 2013 at 13:52:49 UTC, Steven Schveighoffer wrote:
On Thu, 23 May 2013 05:05:01 -0400, Don
<[email protected]> wrote:
On Tuesday, 21 May 2013 at 20:36:20 UTC, Walter Bright wrote:
Join the dmd beta mailing list to keep up with the betas. This one is
pretty much good to go, unless something disastrous crops up.
http://ftp.digitalmars.com/dmd2beta.zip
Remaining regressions:
http://d.puremagic.com/issues/buglist.cgi?query_format=advanced&bug_severity=regression&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED
NO NO NO NO. I am violently opposed to this release.
This beta contains the worst language misfeature of all time. It's
silently snuck in under the guise of a bugfix.
struct S
{
const int x = 7;
int y;
}
In previous releases, S.x was always 7.
But now, if you write
S s = S(5);
then x gets changed to 5.
This means that the const variable x has been initialized TWICE!
This new behaviour is counter-intuitive and introduces a horrible
inconsistency.
I disagree.
struct S
{
const int x;
}
S s1; // x is 0
Of course! It's an uninitialized variable! Try making x a float, and
you'll get NaN.
No, it's initialized to NaN. If it was truly uninitialized, then it would
be garbage, like C.
In other words, *something* writes NaN into that memory location (or 0, or
whatever). The initializer simply dictates what to write.
S s2 = S(5); // x is 5
---
I can see uses. If you don't want x.init to be the default for x, then
you need to set it to something else.
For example:
struct Widget
{
immutable string name = "(unset)"; // instead of ""
}
That is just an awful workaround for the lack of default constructors.
Why? The compiler blits a bit-pattern onto the struct before
initialization. Why should we not be given the ability to control that
bit pattern? It's just data!
I find the argument against this quite puzzling, we should have as much
power as possible over how the compiler treats our custom types. I think
your arguments simply stem from the fact that you did not specify static
for your static variables, and the compiler loosely accepted that until
now.
-Steve
