comeau@panix.com (Greg Comeau) writes:

>"Gary Brown" <gbrown@thebrowns.ultranet.com> writes:
>>Is the following legal C++?
>>
>> class X {
>>     vector<X> ...;
>> };
>
>[...] you can certainly use a template argument with the same name
>as the class you are in, in this way.

You can _sometimes_ use a template argument with the same name
as the class you are in, but sometimes you can't.

For example, the following are legal (well-formed),

 template <class T> struct v1 { T* x; };
 template <class T> struct v2 { T y; };
 struct X {
  v1<X> a;
  v2<X> *b;
 };

but these are not:

 template <class T> struct v3 { T z; };
 template <class T> struct v4 { static const int size = sizeof(T); };
 struct Y {
  v3<Y> c;
  v4<Y> d;
 };

The implementation of the class template `vector' is not specified by
the DWP.  It might be like `v4' above.  Hence, it is unspecified whether

 class X {
     vector<X> ...;
 };

is well-formed or not; such constructs cannot be used in strictly
conforming programs.

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Hi all,

Is the following legal C++?

 class X {
     vector<X> ...;
 };

Borland C++ 4.02 is happy with it.  Visual C++ 4.1 takes it only if the
vector declaration is placed after the constructor declarations.

It is meaningful but might be problematical for the compiler.  That VC++
works only with some fiddling makes me wonder if it is legal.

Thanks,
Gary



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In article <01bbfd2b$67bad860$23f37392@thebrowns> "Gary Brown" <gbrown@thebrowns.ultranet.com> writes:
>Is the following legal C++?
>
> class X {
>     vector<X> ...;
> };
>
>Borland C++ 4.02 is happy with it.  Visual C++ 4.1 takes it only if the
>vector declaration is placed after the constructor declarations.
>
>It is meaningful but might be problematical for the compiler.  That VC++
>works only with some fiddling makes me wonder if it is legal.

I am not clear what you mean by that it required you to code ctor decls???

Anyway, you can certainly use a template argument with the same name
as the class you are in, in this way.  This tends to imply to me that
something is missing, hence I would like to ask that you show the code
that succeeds and the code that fails in order to clarify.

- Greg
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