On Thursday 11 March 2004 04:37 pm, Peter Dimov wrote:
Douglas Gregor wrote:
On Thursday 11 March 2004 10:27 am, Peter Dimov wrote:
Douglas Gregor wrote:
The benefit is that we don't need to introduce a "function_equal" to compare functions and we can still choose whether to support (bind(f, _1) == bind(g, _1))(5)
But there's still the implicit assumption that not introducing function_equal is a benefit. I don't see why this should be so clear cut. What particular problems do you see with function_equal?
I don't use string_equal for strings or shared_ptr_equal for shared_ptr's, so why should I do so for function objects?
Wait a minute. Which "I" are we speaking of here? function<> will use function_equal, but the end users will not be required to even know about its existence. If they want to define operator== for their function objects and then compare them for equality, they are perfectly welcome.
"I" as a user, that wants to compare two function objects that are, say, returned from bind. Anyway, I'm going to back off on this. We'll define function_equal to (by default) use operator==, and overload it for bind/lambda/fc++/mem_fn/etc. function objects to do the actual comparison. Function's operator== (or contains, or whatever survives the discussion in our other thread) will use function_equal. If users are clamoring for the ability to compare function objects returned by bind and whining about using function_equal, we can revisit it down the road. Doug