On Nov 5, 2:12*pm, Pawel Dziepak <pdzie...@quarnos.orgwrote:
Quote:
Noah Roberts wrote:
Quote:
template < typename T1, typename T2, T2 T1::*x >
struct test1
{
};
>
Quote:
struct test2
{
* int x;
>
Quote:
* typedef test1<test2, int, &test2::xtype;
};
>
<snip>
>
Quote:
Compiles with g++ and comeau online (warnings about unused variables)
but MS compiler gives error:
>
<snip>
>
14.3.2/1:
"[Template argument should be one of:] (...) the address of an object or
function with external linkage, including function templates and
function template-ids but *excluding non-static class members*"
>
Compiler wouldn't know the address of test2::x at compile time, that's
why such things are not allowed.
&test2::x does not have an address, it is a pointer to member value.
The very next portion of 14.3.2/1 specifically allows "a pointer to
member as described in 5.3.1" as a non-type template parameter.
I suspect this is indeed a compiler bug, but the details of when a
class member declaration may be referenced get tricky. To separate
the templating from the issue, I wonder if this would be a workaround,
or if not, I'd be curious on which line your compiler gives an error:
struct test2
{
int x;
static int test2::*const ptr_to_x = &test2::x;
typedef test1<test2, int, ptr_to_xtype;
};
