On Jul 9, 2013, at 4:25 PM, Richard Smith <[email protected]> wrote:
> On Tue, Jul 9, 2013 at 11:12 AM, Mike Herrick <[email protected]> wrote:
> Hi,
>
> It appears that this patch for user-defined literals hasn't been applied to
> the document (though it is used by at least g++ and clang).
>
> On Jun 5, 2011, at 4:11 AM, Sean Hunt <[email protected]> wrote:
>
> > Hi,
> >
> > I don't know where to find the document to patch against, but I'd like to
> > suggest that the line
> >
> > ::= li <source-name> # "" <source-name>
> >
> > be added somewhere amongst the productions for <operator-name> in 5.1.3
> > since it's not yet in the document.
>
> Additionally, how about a case like this:
>
> int operator "" _w(const char*);
> template <class T> auto f(T p1) -> decltype(123_w, p1);
> int main() {
> f(456_w);
> }
>
> Clang gives a mangling of _Z1fIiEDTcmclL_Zli2_wPKcELA4_cEEfp_ET_, but g++
> aborts on this case. I don't believe I've seen a discussion of this.
>
> Modeling a UDL as a call to the corresponding literal operator is an accident
> of Clang's implementation rather than a deliberate choice of mangling, but it
> seems reasonable to me.
One follow-up related to the example that is given above; our UDL mangling
produces a slightly different mangled name for this example:
_Z1fIiEDTcmclL_Zli2_wPKcELA4_S0_EEfp_ET_, reflecting a difference in the
cv-qualification of the type of the argument that is being passed to the
literal operator. Clang's demangled name reflects the use of "char [4]" as the
argument type and we're using "const char [4]":
< decltype(((operator "" _w((char [4])"..."),param#1))) f<int>(T1)
---
> decltype(((operator "" _w((const char [4])"..."),param#1))) f<int>(T1)
From a Standards point-of-view, we think "const char [4]" is correct here (the
call to a raw literal operator X is defined to be equivalent to operator ""
X("n"), and the type of "n" is "array of const char"). Is this a clang bug or
the result of some implicit conversion (and if so, should it be reflected in
the mangling)?
Thanks,
Mike Herrick
Edison Design Group_______________________________________________
cxx-abi-dev mailing list
[email protected]
http://sourcerytools.com/cgi-bin/mailman/listinfo/cxx-abi-dev
