Re: How to get rid of the new-initializer in a new-expression

From:

Thomas Maeder <maeder@glue.ch>

Newsgroups:

comp.lang.c++.moderated

Date:

Sat, 16 Feb 2008 05:52:44 CST

Message-ID:

<m2r6fdcm1n.fsf@glue.ch>

"Matthias Hofmann" <hofmann@anvil-soft.com> writes:

template <class T> T* TrackNew( T* ptr ) { return ptr; }

#define NEW( T ) TrackNew<T>( new T )

struct X
{
     X() {}
     X( int ) {}
};

int main()
{
     // Works fine.
     X* p1 = NEW( X );

     // Fails to compile.
     X* p2 = NEW( X( 2 ) );

     return 0;
}

The second use of the NEW macro expands to:

X* p2 = TrackNew<X( 2 )>( new X( 2 ) );

Obviously, this should be:

X* p2 = TrackNew<X>( new X( 2 ) );

Can anyone please tell me a portable way of getting rid of the
new-initializer in the new-expression?

I think so.

Remove the explicit parameter indication and let the compiler deduce
it:

#define NEW( X ) TrackNew( new X )

I also renamed the argument; T has the misleading connotation of
"type" (for me anyway).

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