Re: What has C++ become?

From:

Walter Bright <walter@digitalmars-nospamm.com>

Newsgroups:

comp.lang.c++

Date:

Thu, 12 Jun 2008 11:30:51 -0700

Message-ID:

<uo6dnZIdhOzH9szVnZ2dnUVZ_rDinZ2d@comcast.com>

Pascal J. Bourguignon wrote:

Noah Roberts <user@example.net> writes:

You're calling the STL "low level code" when it is, in fact, high
level code. The find_if algorithm, for instance, is a high level
algorithm that can be used with any data type that obeys the iterator
abstraction.

No. find_if is low level.

Compare:

    Key k;
    std::vector<Element> v;
    std::vector<Element>::iterator end=v.end();
    std::vector<Element>::iterator found;
    found=find_if(v.begin(),end,boost::bind(&Key::equal,k,boost::bind(&Element::getKey,_1)));
    if(found==end){
        doSomething(v,NULL);
    }else{
        doSomething(v,*found);
    }

vs.

    (lambda (k v) (do-something v (find-if (lambda (e) (equal k (get-key e))) v)))

The STL code is a fairly straightforward translation into the D
programming language:

  import std.algorithm;
  Key k;
  Element[] v;
  auto found = find!("k == a.getKey()")(v);
  if (found == end(v))
     doSomething(v, null);
  else
     doSomething(v, *found);

In this specific example, lisp is even higher level (ie. more concise):

I'm not sure I agree with your definition of higher level being more
concise. Doesn't higher level mean more abstract?