Re: A question about TC++PL

From:

"Alf P. Steinbach" <alfps@start.no>

Newsgroups:

comp.lang.c++

Date:

Wed, 16 Jun 2010 11:09:59 +0200

Message-ID:

<hva4dc$b42$1@news.eternal-september.org>

* Bart van Ingen Schenau, on 16.06.2010 10:31:

On Jun 15, 6:11 pm, Chen Zhuhui<eksche...@gmail.com> wrote:

Dear All,

I'm reading appendix C.13.8.3 in TC++PL special ed. and it says:

"
The definition of "instantiation point" implies that a template
parameter can never be bound to a local name or a class member. For
example:

void f()
{
     struct X { /* ... */ }; // local structure
     vector<X> v; // error: cannot use local structure as
                              // template parameter
     // ...
}

........
"

<snip>

So if I haven't misunderstood something, the example is showing about "a
template parameter can never be bound to a local name". But how about "a
class member"? I cannot figure myself out an example of this
situation. I've tried:

struct classA
{
    struct classB { };
    typedef int classC;

    void classAF()
    {
       vector<classB> v1; // 1
       vector<classC> v2; // 2
    }

};

Try this one:

struct class A
{
   struct classB { };
   typedef int class C;

   vector<classB> v1; // 5
   vector<classC> v2; // 6
};

I tried the following code with Comeau Online:

<code>
#include <vector>
using namespace std;

struct classA
{
   struct classB { };
   typedef int classC;

   vector<classB> v1; // 5
   vector<classC> v2; // 6
};

int main()
{ classA(); }
</code>

It compiled with no errors or warnings.

From the given out-of-context quote it's very unclear what Bjarne is talking
about.

Since Appendix C is the one that is not publicly available, and some of us (like
me) do not have the 3rd edition of that book, perhaps the OP could clarify --
and thereby perhaps answering his/her own question...

Cheers & hth.,

- Alf

--
blog at <url: http://alfps.wordpress.com>