Re: [boost] [tr1] Help needed with Darwin port

Subject: Re: [boost] [tr1] Help needed with Darwin port
From: Stuart A. Malone (samalone_at_[hidden])
Date: 2009-01-13 13:37:12

John,

After reading your response and thinking about this problem a bit  
longer, I've come up with two other possible workarounds if the  
#include_next solution doesn't work.

Solution 1.  Create a subdirectory called something like "bridges".   
For each stdc++ header that you need to include, create a bridge  
header in this subdirectory whose name is _not_ the same as the name  
of the original header.  It might look something like this:

File <boost/tr1/iostream>:

        #include <boost/tr1/bridges/iostream-bridge.hpp>

File <boost/tr1/bridges/iostream-bridge.hpp>:

        #include <iostream>

I _think_ that the #include in the bridge header will reliably locate  
the original stdc++ <iostream> header, since there is no file named  
"iostream" in the current directory and the bridges directory is not  
on the search path.

Solution 2.  Include some stdc++ header that is _not_ being redefined,  
and then use the value of __GLIBCXX__ to determine the path to the  
other headers.

        #if defined(__GLIBCXX__)
          #if __GLIBCXX__ == 20050421
            #include <c++/4.0.0/iostream>
          #elif __GLIBCXX__ > 20050421
            #include <c++/4.2.1/iostream>
          #else
            #error Unknown version of the GCC stdc++ library
          #endif
        #endif

I certainly don't recommend this since it is so fragile, but a  
solution like this might work if nothing else does.  Let me know if  
you choose to go this route and I'll try to come up with the possible  
values of __GLIBCXX__ for you and the corresponding paths.

I'd also be happy to do a few test builds for you once you think  
you've come up with a solution, since we do have a vested interest in  
this working correctly.  ;)

--Stuart