[Boost-users] Detect specialized template function?

Subject: [Boost-users] Detect specialized template function?
From: dherring_at_[hidden]
Date: 2010-01-28 15:24:19

Slightly OT, but I was hoping someone here might know the magic incantation 
(which may involve a Boost library).

Given a template class such as

template <class T>
struct S
{
   void f();
   void g() { T t(h()); cb(t) }
   T & h();
   boost::function1<void, T &> cb;
};

Is there a way to have S.f() behave differently depending on whether S.g() uses 
the default definition or whether it is specialized for this particular type? 
This detection needs to occur before S.g() is ever called.

For example, the mere existance of the specialization
template <> void S<int>::g() { ... }
should trigger special logic in S<int>::f().

Thanks,
Daniel

P.S.  The motivation for this is an attempt to retrofit a callback API that 
allows specialization of S.g() or the registration of a boost::function that 
gets called by the default S.g().  We need to disable callbacks until an actual 
function is registered via either method.  It is easy to dispatch on 
registration of the boost::function; I don't know how to detect the 
specialization.