BIND 10 #2144: add nonassignable super class

[BIND 10 Development]

#2144: add nonassignable super class
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            Reporter:  fdupont       |                        Owner:
                Type:  enhancement   |  UnAssigned
            Priority:  medium        |                       Status:
           Component:  Unclassified  |  reviewing
            Keywords:                |                    Milestone:
           Sensitive:  0             |  Sprint-20130402
         Sub-Project:  DNS           |                   Resolution:
Estimated Difficulty:  2             |                 CVSS Scoring:
         Total Hours:  0             |              Defect Severity:  N/A
                                     |  Feature Depending on Ticket:
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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Comment (by jinmei):

 '''general'''

 I first created a new branch from the original trac2144 and rebased it
 on the latest master, as there have been many changes since the
 original branch.  The new branch is trac2144-2.  I suggest we made
 further changes on this new branch (and we should probably just remove
 the old one to avoid confusion).

 I've not examined all cases where noncopyable or nonassignable is
 newly introduced to confirm they are really necessary and whether
 noncopyable/nonassignable is the best choice (especially because my
 compiler doesn't warn about the things reported in this ticket).  It's
 also possible that there are some new cases where noncopyable or
 nonassignable would now be needed.

 In addition to conflict resolution, I made some other cleanups in my
 own commits.  5b4d247 should be trivial, and I believe the rest is not
 problematic, but you may want to check them.

 '''nonassignable.h and noncopyable.h'''

 - First off: do we need our own noncopyable, if it's just a copy of
   Boost?
 - Please add documentation: brief description of what it is, the
   purpose of these classes, in which case we should use which, and
   why, etc.
 - Shouldn't we also copy Boost copyright?
 {{{#!cpp
 /// From boost/noncopyable.hpp
 }}}
   even though the definition is quite trivial.
 - what's the intent of the postfix underscore in `noncopyable_`?
 {{{#!cpp
 namespace noncopyable_ {
 }}}
   and the typedef?
 {{{#!cpp
 typedef noncopyable_::noncopyable noncopyable;
 }}}

 '''labelsequence'''

 - (Especially) if we define our own `operator=`, it should be tested
 - And, if we really need it, I guess we don't need to include this:
 {{{#!cpp
 #include <util/nonassignable.h>
 }}}
 - The restriction of the assignment operator seems quite counter
   intuitive and inconvenient.  What's the rationale of it?  At the
   very least this should be documented.

-- 
Ticket URL: <http://bind10.isc.org/ticket/2144#comment:10>
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