On Friday 05 June 2015 19:04:51 Gavin Lambert wrote:
What is the reason that Boost WinAPI redeclares the structure? Can it be changed to just use the one from the Windows headers (perhaps via typedef, if the internal typename is needed for compatibility)?
(After writing the above, a cursory glance at the code suggests that it does do that if BOOST_USE_WINDOWS_H is defined. So that changes the question: under what conditions is that not defined?)
The reason of Boost.WinAPI existence is that people don't want to include windows.h, especially in public headers. It is a heavy header that brings in most of SDK. It depends on predefined macros, so including it once defines the API users will be able to use; this is inconvenient for both Boost and its users. Also, windows.h defines a few offending macros, like min/max. In order to provide Windows API Boost.WinAPI has to redefine functions and structures from Windows SDK in a binary compatible way but in the way it doesn't conflict with windows.h. That's the current implementation. BOOST_USE_WINDOWS_H is a macro that can be defined by the user if he wants Boost to include windows.h. There's not much practical point in this except to solve compatibility problems like in the original post.