questions about cv-qualifier for function and references

questions about cv-qualifier for function and references

[zhang qingshan]

std(N3126) 8.3.2/1 says that:

Cv-qualified references are ill-formed except when the cv-qualifiers
are introduced through
the use of a typedef (7.1.3) or of a template type argument (14.3), in
which case the cv-qualifiers are ignored.

Why the following code compiled failed on GCC 4.5.0 ?
  template <typename T> void foo (T const &);
  void baz ();
  foo (baz);

while
 template <typename T> void foo (T const &);
 void baz ();
 void Test() {
   foo (baz);
 }

successfully. Really wired.

another question is: what is cv-qualifier reference ? Your guys told me that:
const int &m; is not a cv-qualifier reference. Could you give me an
example on the cv-qualifier reference ? Thanks.

Re: questions about cv-qualifier for function and references

[Jonathan Wakely]

On 2 December 2010 04:52, zhang qingshan wrote:
> std(N3126) 8.3.2/1 says that:
>
> Cv-qualified references are ill-formed except when the cv-qualifiers
> are introduced through
> the use of a typedef (7.1.3) or of a template type argument (14.3), in
> which case the cv-qualifiers are ignored.
>
> Why the following code compiled failed on GCC 4.5.0 ?
>  template <typename T> void foo (T const &);
>  void baz ();
>  foo (baz);

you can't call a function at namespace scope
This is the same as:

void foo() { }
foo();

The template and the reference has nothing to do with it.

> while
>  template <typename T> void foo (T const &);
>  void baz ();
>  void Test() {
>   foo (baz);
>  }
>
> successfully. Really wired.

No, that's completely normal, at function scope you can call another function.
Like:
void foo() { }
void bar() {
  foo();
}

> another question is: what is cv-qualifier reference ? Your guys told me that:
> const int &m; is not a cv-qualifier reference. Could you give me an
> example on the cv-qualifier reference ? Thanks.

int i = 0;
int& const cref = i;   // error - cannot have cv-qualified reference