Re: Ada The Best Language?

[Lao Xiao Hai <laoxhai@ix.netcom.com>]

ANH_VO@udlp.com wrote:

> Codesavvy, for a start, can a linked list be implemented in C++ without pointer?

Ahn,

Yes it can.  Well, yes it can if what you mean by a pointer is a raw pointer.
Sadly,
this is the kind of pointer most C++ programmers routinely use.   Ada raises the
level of abstraction and calls a pointer an access type (as Java calls it a
reference),
thereby hiding the dangerous aspects of indirection beneath a compiler-enforced
mechanism.  In the case of Ada, a pointer, AKA access type, is safe by default.  A
C++ pointer is unsafe, by default.   We can relax the safety features of an access
type through a variety of unchecked and library features.   In C++, we raise the
level of abstraction through the use of a "smart pointer" class.  This, in many
ways,
is equivalent to an access type, except it may have built-in garbage collection.
The
smart pointer restricts the set of operations on an object of its type in much the
same
way an access type does in Ada.

Unfortunately, most C++ programmers either do not understand how to use smart
pointers or regard them as "inefficient."    Also, few college professors know
enough
about them to properly teach their use in object-oriented programming classes.

Richard Riehle