Re: [boost] function and VC6 and BOOST_NO_DEPENDENT_NESTED_DERIVATIONS

From: John Maddock (John_Maddock_at_[hidden])
Date: 2001-07-14 06:29:44

>template<typename T> struct foo {
>  template<typename U> struct bar : public foo<U> {};
>};

Thanks that works.

>I think it is the same MSVC bug as in the above ::template misparsing.
MSVC 
>insists on finding a type (i.e. foo<U> or other<U>) but isn't satisfied by

>finding a template type parameter, so it crashes. For reference, Borland 
>fails all of these testcases.

For some reason, I'm not seeing any problems with nested templates and
VC6sp3, or with VC7b1.

The following works just fine:

struct UDT1{};
struct UDT2{};

template<typename T> 
struct foo 
{
  template<typename U> 
  struct bar : public foo<U> 
  {};
};

template <class T>
void foo_test(T)
{
   typedef foo<T> foo_type;
   typedef typename foo_type::template bar<UDT2> bar_type;
   foo<T> ft;
   bar_type bt;
   (void)bt;
   (void)ft;
};

int test()
{
   foo_test(UDT1());
   return 0;
}

- John Maddock
http://ourworld.compuserve.com/homepages/john_maddock/