On 5/10/06, amol <gajewar.amol@xxxxxxxxxxxxxxx> wrote:
Following is the code which works on windows but can't work with g++
template < class my_type>
class mytypedef
{
public :
typedef my_type new_type;
};
template <class my_type>
class sample: public mytypedef < my_type >
{
public :
new_type var;
};
Error : new_type doest not name a type.
Why is it happening?
What is solution for this problem?
Amol Gajewar
Solution ,as suggested by g++(4.0.2) itself works
myshec-linux:~ # g++ -c temp.cpp
error: 'new_type' does not name a type
note: (perhaps 'typename mytypedef<my_type>::new_type' was intended)
when i used what g++ suggested (the part which follows note :it worked )
what i think is :
first compiler will not look for definition of new_type in the base
class scope ,there was a similar thread today which pointed to this
URL
http://gcc.gnu.org/ml/gcc-help/2004-04/msg00382.html
second , the typename keyword is needed ,otherwise the compiler will
not believe that
new_type is a type , it will assume it as a static member or a enum or
an object ,but it wont-cannot know that it is a type , until the
template is instantiated...so u have to use typename.
VC++ rules might be different , but this is the standard.
HTH
Digz
