Why aren't wide string literals zero-terminated just like strings?

[Steven Schveighoffer]

On Wed, 18 May 2011 16:57:37 -0400, Andrej Mitrovic <none at none.none> wrote:

> Skip the rest of the code until you reach main:
> http://codepad.org/zPAgFnPX
>
> We have this notion that string *literals* are zero-terminated, which  
> enables us to send them to C functions expecting zero-terminated char*  
> strings.
>
> But the same doesn't apply to wide string literals, e.g. "somestring"w.

Yes it does...

steves at steve-laptop:~/testd$ cat teststringlit.d
wstring ws = "abcde"w;
steves at steve-laptop:~/testd$ ~/dmd-2.053/linux/bin32/dmd -c teststringlit.d
steves at steve-laptop:~/testd$ ~/dmd-2.053/linux/bin32/obj2asm  
teststringlit.o

....

.rodata	segment
	db	061h,000h,062h,000h,063h,000h,064h,000h	;a.b.c.d.
	db	065h,000h,000h,000h	;e...
.rodata	ends

....

> If it did, its would save quite a bit of typing when calling WinAPI  
> functions that expect wide strings, instead of having to call  
> "somestring".toUTF16z.
>
> So currently:
> immutable(char)[] literal implicitly convertible to const(char)* and  
> char*.
> immutable(wchar)[] literal not implicitly convertible to const(wchar)*  
> and wchar*.

That doesn't make sense... hm...

tried it out, definitely a bug.  I get the error:

teststringlit.d(7): Error: function teststringlit.foo (const(wchar)*  
widestr) is not callable using argument types (immutable(wchar)[])
teststringlit.d(7): Error: cannot implicitly convert expression ("abcde"w)  
of type immutable(wchar)[] to const(wchar)*

A wstring literal should be able to be passed to a const(wchar)* parameter.

So the literal *is* zero terminated, but the compiler isn't letting you  
pass it directly to a const(wchar)*.

Please file with bugzilla.  As a workaround, you should be able to do  
"somestring"w.ptr;

-Steve