Re: [boost] [function types] New tag type logic

From: Rob Stewart (stewart_at_[hidden])
Date: 2005-06-29 13:29:19

From: Jonathan Wakely <cow_at_[hidden]>
> On Wed, Jun 29, 2005 at 10:46:47AM -0400, David Abrahams wrote:
> > Tobias Schwinger <tschwinger_at_[hidden]> writes:
> > 
> > >      A tag encapsulates one or more aspects of the kind of type.
> > >
> > >      Tags which only encapsulate variations of a single aspect are called
> > >      *aspect tags* in the following text (see reference).
> > >
> > >                                                ^^^
> > >                                              links to:
> > 
> > Lovely!  "which" should be "that," though, at least by U.S. English
> > rules" Normally, "which" should only follow a comma in a fragment that
> > could be removed without altering the meaning of a sentence, as in "I
> > felt lousy, which might have been good since I didn't want to go
> > anyway."
> 
> That seems wrong to me.  A style-guide which requires that is being a
> bit picky IMHO.
> 
> c.f. Chambers:
> http://www.chambersharrap.co.uk/chambers/chref/chref.py/main?title=21st&query=which
> Your rule seems only to apply to the 3rd definition, which is not the
> sense in which Tobias is using "which".

Merriam Webster's Dictionary of English Usage, (c) 1994,
pp894f, provides much discussion of the matter.  It seems
"that" predates "which," but fell into disrepute.  It later
reappeared and now enjoys some parity with "which."

The conclusion of the long section is:

   If the discussion in many of the handbooks are complex and
   burdened with exceptions, the facts of usage are quite
   simple.  Virginia McDavid's 1977 study shows that about 75
   percent of the instances of "which" in edited prose introduce
   restrictive clauses; about 25 percent, nonrestrictive ones.

   We conclude that at the end of the 20th century, the usage of
   "which" and "that"--at least in prose--has pretty much settled
   down.  You can use either "which" or "that" to introduce a
   restrictive clause--the grounds for your choice should be
   stylistic--and "which" to introduce a nonrestrictive clause.

Thus, Tobias' use of "which" to introduce the restrive clause is
fine.  (Note that M-W didn't provide data indicating how often
"which" is used versus "that" when introducing restrictive
clauses.  Thus, we cannot judge whether "that" is used more often
than "which" to introduce restrictive clauses.)

-- 
Rob Stewart                           stewart_at_[hidden]
Software Engineer                     http://www.sig.com
Susquehanna International Group, LLP  using std::disclaimer;