Re: [boost] Re: Coding guidelines - noncopyable

From: Beman Dawes (bdawes_at_[hidden])
Date: 2001-07-10 14:36:58

At 12:44 PM 7/10/2001, Michael Kenniston wrote:

 >Ronald Garcia wrote:
 >
 >> Peter Dimov writes:
 >>  >
 >>  > "15.6. Keep in mind that the compiler will implicilty generate a 
copy
 >>  > constructor, assignment operator and a destructor if you don't 
declare
 >them
 >>  > explicitly. If you rely on this behavior, document it using a 
comment
 >inside
 >>  > the class body:
 >>  >
 >>  > // implicitly generated members are fine and useful
 >>  > "
 >>
 >> I dont think one should have to state that the implicitly generated
 >> members are okay.  I'd say that the absence of either
 >> boost::noncopyable or the private declaration of components would say
 >> enough.  This comment seems to go against the grain of the language.
 >>
 >> ron
 >
 >I disagree.  The cost of including the comment is close to zero.
 >The cost of /not/ including it is the time (at least a minute, and 
possibly
 >much longer) that a programmer unfamiliar with the code has to spend
 >to decide if the omission of the ctor/assign/dtor was deliberate or
 >accidental.
 >With a comment, the question is answered -- definitively -- in a second 
or
 >two.
 >
 >In other words, you are quite correct that the comment is not required to
 >specify the program's behavior, but given how easy it is to goof this up,
 >I think the comment is useful to specify whether that behavior is
 >intentional.

I agree with Michael.  A comment specifying in effect that "compiler 
generated functions are expected and useful" can be a big help.

--Beman