[Bug c++/33124] C++ frontend should not warn about new a[0] in template context

["gdr at cs dot tamu dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #3 from gdr at cs dot tamu dot edu  2007-08-20 23:23 -------
Subject: Re:  C++ frontend should not warn about new a[0] in template context

"mec at google dot com" <gcc-bugzilla@gcc.gnu.org> writes:

| "new T[0]" looks like defined behavior to me.
| 
| [expr.new] 5.3.4 -7-
| When the value of the expression in a direct-new-declarator is zero, the
| allocation function is called to allocate an array with no elements.  The
| pointer returend by the new-expression is non-null.  [Note: if the library
| allocation function is called, the pointer returned is distinct from the the
| pointer to any other object.]
| 
| ===
| 
| cp/init.c even quotes that section in a comment before giving the warning. 
| cp/init.c goes on to say "However, that is not generally useful, so we issue
a
| warning".  new T[0] is valid C++ and here is a useful case.

Thanks for reminding me that the construct is NOT undefined beahviour.  

That, I think, also supports the case that we should NOT disable
the warning for template instantiations.

-- Gaby


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33124