Why I (Still) Won't Use D

[Sean Kelly]

== Quote from Janice Caron (caron800 at googlemail.com)'s article
> On 28/03/2008, Walter Bright <newshound1 at digitalmars.com> wrote:
> > Yet I'm always left wondering what is the difference between vector and
> > string?
> In Microsoft Visual Studio's implementation, std::string implements
> copy-on-write, wheras std::vector doesn't.

I'm sorry, but unless I missed a memo, this hasn't been the case for probably
ten years.  It's been shown fairly conclusively that STL-conformant COW strings
are incompatible with multithreaded programs, and Dinkumware has long since
switched them for a non-COW design.  Did they change them back with VS 8.x?

Personally, I think the difference between vector and string is largely in the
operations they support.  Here are the gaps, from a quick glance at the standard:

vector:
  back
  front
  pop_back

string:
  append
  c_str
  compare
  copy
  data
  find
  find_first_not_of
  find_first_of
  find_last_not_of
  find_last_of
  length
  npos
  operator+=
  operator=
  replace
  rfind
  substr

The important thing to note about the routines added to string (such as find) is
that they have overloads which accept value_type* as an argument, for easy
integration with C-style strings.  c_str and data are much the same, and one
can assert that strings may always be ordered while vectors may not (ie. compare).
Overall though, I find the D approach to make more sense.  Strings are really just
a sequence of characters, so why bother with two separate containers?  However,
I wouldn't be surprised if a redesign today did something along these lines as
well, and relied on <algorithm> plus perhaps some helper functions to handle
the various operations currently embedded for convenience in the classes
themselves.


Sean