Re: STL compatibility in MS VS 2003/2005

From:

"Carl Daniel [VC++ MVP]" <cpdaniel_remove_this_and_nospam@mvps.org.nospam>

Newsgroups:

microsoft.public.vc.stl

Date:

Thu, 19 Oct 2006 07:40:35 -0700

Message-ID:

<upQILy48GHA.568@TK2MSFTNGP05.phx.gbl>

Tom Widmer [VC++ MVP] wrote:

1. Use COM, thus using BSTR instead.

Painful perhaps, but you get absolutely the broadest range of compatible
target environments.

2. Export either a C++ API using no std::containers, or even a C API.
Note that the memory for the char* must be deallocated by the same
module that allocated the memory (since the modules will be using
different CRT heaps), so your DLL will need to export a "free memory"
function of some kind, or it should model itself on most C libraries,
where you pass in the buffer rather than it being returned (thus the
DLL doesn't do any memory allocation of user buffers).

i.e. "do as Windows does". The API is in C, even though large portions of
Windows (outside the kernel) are written in C++.

3. (An improvement on 2) Do the above, but additionally provide a
source code library that the user can add to their code that wraps up the
usage of the API in nice C++ classes, using standard containers. Since
this
code is then compiled by their compiler, no compatibility problems
exist.

This is the route I've taken in the past. It's a bit of trouble, no doubt,
but the end result is quite pleasing: you get your nice C++ api AND you get
compiler independence.

-cd