Re: Overloading on a pointer and an array type

"Bart van Ingen Schenau" <bart@ingen.ddns.info> schrieb im Newsbeitrag
news:9485383.nPOeAJ2rxQ@ingen.ddns.info...


Great, this is just the solution to a problem I had with having a template
function forward the call to helper classes to emulate function template
partial specialization! :-) Here's the new code:

#include <cstddef>
#include <iostream>

// Extracts the type of an object.
template <class T>
struct extract { typedef T type; };

// Extracts the type of an array.
template <class T, std::size_t N>
struct extract<T[N]> { typedef T type; };

// Primary template for object new.
template <class T> struct TrackNewHelper
{
     static T* TrackNew( T* ptr, const char* file, int line)
     {
         std::cout << "Tracking object allocation" << std::endl;
         return ptr;
     }
};

// Partial specialization for array new.
template <class T, std::size_t N> struct TrackNewHelper<T[N]>
{
     static T* TrackNew( T* ptr, const char* file, int line)
     {
         std::cout << "Tracking array allocation " << std::endl;
         return ptr;
     }
};

// Forwards the call to helper classes.
template <class T> typename extract<T>::type* TrackNew(
     typename extract<T>::type* ptr, const char* file, int line )
{
     return TrackNewHelper<T>::TrackNew( ptr, file, line );
}

#define NEW( T ) TrackNew<T>( new T, __FILE__, __LINE__ )

int main()
{
    int * p = NEW( int ); // Calls the primary template.
    delete p;

    p = NEW( int[64] ); // Calls the partial specialization.
    delete [] p;

    return 0;
}

Anyway, thank you very much for your solution! And if anyone is interested
in what my problem was, then try to implement the above without the
'extract' helper classes... ;-)

--
Matthias Hofmann
Anvil-Soft, CEO
http://www.anvil-soft.com - The Creators of Toilet Tycoon
http://www.anvil-soft.de - Die Macher des Klomanagers

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