Re: Which libraries in Boost are mature enough to be used in real applications?
Noah Roberts wrote:
class X { Y private_y; }; // Now you also have to include the
definition of Y even though Y is only used privately by X.
And that does break "encapsulation" if that is defined as hiding the
implementation from the user. Using a pointer to Y (scoped_ptr if you
prefer) you can forwardly declare the Y and that hides the
implementation detail better. Particularly if there is only one such
pointer (a pointer to the implementation).
You can always say "this is a black box, don't look inside" and
generally we do adopt that approach when using, for example,
std::string and std::vector. That is fine on the whole.
But as I mentioned, std::string is not portable across libraries. And I
will explain what I mean.
I have, say, a library that I have written and compiled using GCC
compiler 3.2.1 that sits on the system and has an interface that takes,
for example, a const std::string & or even worse, a function that
returns a std::string.
Your application is being compiled with Solaris Forte 8 compiler with
Roguewave STL and tries to interact with my library. Although we are
both using a standard string class with the same interface, they are
possibly implemented differently and when you pass yours by reference
to mine, it may compile fine but may seg-fault when run.