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Re: C/C++ FEs: Do we really need three char_type_nodes?


Joe Buck wrote:
On Tue, Sep 23, 2008 at 05:51:23PM -0400, Jason Merrill wrote:
Mark Mitchell wrote:
Is that desirable?  Type-based alias analysis should be able to take
advantage of the difference between them; a "char **" and a "signed char
**" cannot point at the same thing, for example.
They can. In C++, a char* (or unsigned char*) can alias anything, and any signed/unsigned type can alias the other signage.

Right, but a char** points to a char*, and a signed char** points to a signed char*. The aliasing exception for char pointers doesn't cover this case the way it does for the "one star" case.

Oops, I was overlooking the second *.


Jason


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