On the Windows platform, special export declarations are required to make
functions or classes in a .dll file accessible to the outside world. For
normal usage of Boost.Extension, the only place this is required is in the
one function that is exported from each .dll. The Hello World sample program
illustrates how this is done using
For implementation inheritance across shared libraries, such as that in the Multiple Inheritance sample, each class that is not header-only that needs to be exported must have these declarations included. To make it more difficult, they must be different depending on whether the class is being imported into or exported from the current module. The Multiple Inheritance sample shows how this is done.
Now for a word of warning that many of you will ignore: In the great majority of cases, even if non-header-only implementation inheritance across shared libraries seems like a good idea, there is probably a better solution. Although it certainly has its uses, it can cause problems like the following: