template declaration

Hi Everyone,

we use the following in the template declaration,

template <class T>

template<typename T>

Is it that typename is preferred as it can be used for all types,
where as class can only be used for custom class types?

Thanks in advance!!!

Rahul

On 2008-01-13 13:11, Rahul wrote:
> Hi Everyone,
>
> we use the following in the template declaration,
>
> template <class T>
>
> template<typename T>
>
> Is it that typename is preferred as it can be used for all types,
> where as class can only be used for custom class types?

No, whether you use class or typename here does not matter as far as the
compiler is concerned. I prefer to use typename and only use class for
class declarations.

--
Erik Wikström

Erik Wikström

Rahul wrote:
> Hi Everyone,
>
> we use the following in the template declaration,
>
> template <class T>
>
> template<typename T>
>
> Is it that typename is preferred as it can be used for all types,
> where as class can only be used for custom class types?
>
> Thanks in advance!!!

Both keywords have the same effect here, so it's just a coding style issue.
IIRC, according to "C++ Template: The complete Guide":

when the template parameter is not always a "class type"(including
/class/ /struct/, /union/), in this case, use /typename/:

e.g.

template <typename T>
class A { T t; };

class B {};

A<B> a1;
A<int> a2; // int is not a class type

In the case when the template parameter should be a "class type", use
/class/,

Additionally, when the template argument is of template template
argument, only /class/ can be used.

e.g.

template <template <typename> class TT>
^^^^^
class A;

HTH

--
Thanks
Barry

Barry