Aleksey Gurtovoy wrote:
> Proposed resolution: change the example to read:
>
>     template<typename T> class number {
>     public:
>         number(int);
>         //...
>         friend number gcd(number& x, number& y);

 I also suggest to use const references ;)

>         //...
>     };
>
>     void g()
>     {
>         number<double> a(3), b(4);
>         //...
>         a = gcd(a,b);   // finds gcd because number<double> is an
>                         // associated class, making gcd visible
>                         // in its namespace (global scope)
>         b = gcd(3,4);   // ill-formed; gcd is not visible

                          // ill-formed: can't bind number(3) to number&

>     }
--
         With all respect, Sergey.          http://cpp3.virtualave.net/
         mailto : ders at skeptik.net

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 [Moderator's note: this defect report has been
 forwarded to the C++ committee. -moderator.]

The example in 14.6.5 [temp.inject] paragraph 2 is incorrect:

    template<typename T> class number {
        number(int);
        //...
        friend number gcd(number& x, number& y) { /* ... */ }
        //...
    };

    void g()
    {
        number<double> a(3), b(4);
        //...
        a = gcd(a,b);   // finds gcd because number<double> is an
                        // associated class, making gcd visible
                        // in its namespace (global scope)
        b = gcd(3,4);   // ill-formed; gcd is not visible
    }

Regardless of the last statement ("b = gcd(3,4);"), the above code is
ill-formed:

  a) number's constructor is private;
  b) the definition of (non-void) friend 'gcd' function does not
contain a return statement.

Proposed resolution: change the example to read:

    template<typename T> class number {
    public:
        number(int);
        //...
        friend number gcd(number& x, number& y);
        //...
    };

    void g()
    {
        number<double> a(3), b(4);
        //...
        a = gcd(a,b);   // finds gcd because number<double> is an
                        // associated class, making gcd visible
                        // in its namespace (global scope)
        b = gcd(3,4);   // ill-formed; gcd is not visible
    }


Aleksey
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