Re: std::tr1::unordered_set problem in GCC 4.1.2

From:

Pete Becker <pete@versatilecoding.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Sun, 8 Apr 2007 15:32:13 CST

Message-ID:

<hNWdnSoVZfLfoYTbnZ2dnUVZ_vKunZ2d@giganews.com>

Howard Hinnant wrote:

Your class actually looks like:

class Traxboard {
    public:
      Traxboard();
      bool operator==(const Traxboard& another) const;
      bool operator&();
      int getHash() const;
};

The gcc code is taking the address of a Traxboard and you're returning a
bool. gcc wants a Traxboard* when it says &(some expression yielding an
lvalue Traxboard).

Which is, nevertheless, a gcc bug, since the key type for an unordered
container is allowed to overloaed operator&. Of course, that's not a
good idea, and should probably not be allowed. It wreaks havoc unless
library code that needs an address carefully works around it.

--

    -- Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com)
Author of "The Standard C++ Library Extensions: a Tutorial and
Reference." (www.petebecker.com/tr1book)

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