function templates

[Helge Kruse]

Hello,

I want to implement a function template separated from the
declaration:

class X
{
public:
template<class T> void operator << (T);
};

template<class T> void X::operator << (T t)
{
}

I got the error:
binary '<<' : 'class X' does not define this operator or a conversion
to a type acceptable to the predefined operator

When I implement the function inside the class X, everything is OK.
How can this be solved, when the function "operator <<(T)" must be
outside of the class X?

Compiler is Microsoft Visual C++ for Windows CE 3.0.

Regards,
Helge

[Gernot Frisch]

Re: function templates


"Helge Kruse" <Helge.Kruse-nospam@gmx.net> schrieb im Newsbeitrag
news:3ffa0259.0 411160108.23a94 850@posting.goo gle.com...[color=blue]
> Hello,
>
> I want to implement a function template separated from the
> declaration:
>
> class X
> {
> public:
> template<class T> void operator << (T);
> };
>
> template<class T> void X::operator << (T t)
> {
> }
>
> I got the error:
> binary '<<' : 'class X' does not define this operator or a
> conversion
> to a type acceptable to the predefined operator
>
> When I implement the function inside the class X, everything is OK.
> How can this be solved, when the function "operator <<(T)" must be
> outside of the class X?
>
> Compiler is Microsoft Visual C++ for Windows CE 3.0.
>
> Regards,
> Helge[/color]

The template class definition must be in the header file. Or include
an .inc file in the header.

[Rob Williscroft]

Re: function templates

Helge Kruse wrote in news:3ffa0259.0 411160108.23a94 850@posting.goo gle.com
in comp.lang.c++:

[color=blue]
> Compiler is Microsoft Visual C++ for Windows CE 3.0.[/color]

That's you problem, your code is perfectly good C++, but
some Microsoft compilers do like template members to be
*defined* inside the body of the class.

Workaround for non-inline:

struct X;
template < typename T > void op_shift_left( X *, T );

struct X
{
template < typename T >
void operator << ( T t )
{
op_shift_left( this, t );
}
};

template < typename T >
void op_shift_left( X *that, T t )
{
// real *non-inline* defenition here.
}

HTH.

Rob.
--

http://www.victim-prime.dsl.pipex.com/