On 07/07/2007 11:49 AM, Eric Niebler wrote: [snip]
template<typename Expr> struct wrap { explicit wrap(Expr const &expr) {} };
Thanks very much Eric; however, I found that with the following: template<typename Expr> struct wrap #define INHERIT_EXPR #ifdef INHERIT_EXPR : Expr #endif { explicit wrap(Expr const &expr) { std::cout<<"Wrap::CTOR\n"; } }; the wrap CTOR is not called when: WrapItUp::call( _1 + _2, i, i ); is executed. OTOH, if INHERIT_EXPR is undefined, then wrap CTOR *is* called. There must be some typedef needed by wrap in order for WrapItUp::call to actually call the wrap CTOR. I'll start looking for it, but I'd appreciate any clues. TIA. -Larry