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Re: constants vs. ODR

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Balog Pal wrote:

>
>  If I have the following in a header:
>
>  const int NUM = 42;
>  inline void foo(const int&) { ... } // could be template, etc
>  inline void bar()
>  {
>   foo(NUM);
>  }
>
>  If I understand correctly, by the current standard this will break the one
>  definition rule, if the header is included in multiple translation units.
>  Because of the const hack that makes it static, so NUM will really be
>  different in every TU, therefore bar() will have non-identical
>  definitions. Placing the program in UB land.
>
>  My question is whether this was fixed for C++0x?
>

This wasn't really fixed, in my opinion. The ODR in the spec says that NUM
should be used in the way that "the value (but not the address) of the
object is used", in order to make the above example well-defined when
included into multiple TUs.

In your case, you bind the object to a reference, and I would say that this
crosses the boundary of allowed interpretation variety of that ODR rule.


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Thread

constants vs. ODR  "Balog Pal" <pasa@lib.hu> - 2011-04-28 12:19 -0600
  Re: constants vs. ODR Johannes Schaub<schaub.johannes@googlemail.com> - 2011-04-28 15:47 -0600
  Re: constants vs. ODR Daniel Krügler<daniel.kruegler@googlemail.com> - 2011-04-28 15:46 -0600
    Re: constants vs. ODR "Balog Pal"<pasa@lib.hu> - 2011-05-01 10:14 -0600
      Re: constants vs. ODR  Johannes Schaub <schaub.johannes@googlemail.com> - 2011-05-01 12:52 -0600
      Re: constants vs. ODR Daniel Krügler <daniel.kruegler@googlemail.com> - 2011-05-06 13:07 -0600

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