On Friday, 14 September 2012 at 15:00:29 UTC, Don Clugston wrote:
On 14/09/12 14:50, monarch_dodra wrote:
On Friday, 14 September 2012 at 11:28:04 UTC, Don wrote:
--- Comment #0 from Don <clugd...@yahoo.com.au> 2012-09-14
04:28:17
PDT ---
Array literals of char type, have completely different
semantics from
string
literals. In module scope:
char[] x = ['a']; // OK -- array literals can have an
implicit .dup
char[] y = "b"; // illegal
A second difference is that string literals have a trailing
\0. It's
important
for compatibility with C, but is barely mentioned in the
spec. The
spec does
not state if the trailing \0 is still present after
operations like
concatenation.
I think this is the normal behavior actually. When you write
"char[] x =
['a'];", you are not actually "newing" (or "dup"-ing) any
data. You are
just letting x point to a stack allocated array of chars.
I don't think you've looked at the compiler source code...
The dup is in e2ir.c:4820.
So the
assignment is legal (but kind of unsafe actually, if you ever
leak x).
Yes it's legal. In my view it is a design mistake in the
language.
The issue now is how to minimize the damage from it.
Thank you for taking the time to educate me. I still have a bit
of trouble with static vs dynamic array initializations: Things
don't work quite as in C++, which is confusing me. I'll need to
study a bit harder how array initializations work. Good news is
I'm learning.
I think ALL my comments were wrong.
In that case, you are right, since:
char[] x = "a".dup;
Is legal.
Good point. For anybody reading though, the actual code
example should be
enum char[] x = foo(true); // ok
enum char[] y = foo(false); // rejected!
No it should not.
The code example was correct. These are static variables.
I hadn't thought of static variables: I placed your code in a
main, and both produced a compilation error. The enums reproduced
the issue for me however.
I think this would work with my "m" suggestion
Not necessary. This is only a question about what happens with
the compiler internals.
Yes.
