Bruno Lalande wrote:
Hi John,
Thanks to have taken the time to test my code. You had the same result as Barend, who was able to reproduce the problem with GCC cygwin (3.4.4) but not MSVC. But the strange thing is that for me, the problem occurs for any compiler (MSVC or GCC). I really don't understand. Here is the list of compilers tested: - Barend: MSVC 8 Express (succeeds), cygwin GCC 3.4.4 (fails) - Me: MSVC 8 (fails), MSVC 9 Express (fails), GCC 4.2.3 (fails)
I don't think there can be any functional difference between the express and normal version of the same MSVC so I don't understand. Could you precise the exact version you used?
I've attached my MSVC compilation results to the mail.
Bruno The code in the email did not have headers, so I added
#include <iostream> #include <boost/concept_check.hpp> #include <boost/concept/requires.hpp> Then I tested with Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 14.00.50727.762 for 80x86 (that is the professional version) It worked. As I said before, mingw-gcc 4.3.0 fails, but it looks like that is the norm for gcc. I think boost is using the fact that the compiler should fail to define a nested enum when a concept assert fails, but that SFINAE should not consider that an error. It looks like it is doing this so that it can chain together many concept checks. I think this must be a bug, so I added a ticket http://svn.boost.org/trac/boost/ticket/2137. The exact sourcecode I used is attached. It looks to me like in boost/concept_check/where_fail.cpp they are not testing *why* the concept check fails. I think in g++ it should be saying something like where_fail.cpp:11: error: no matching function for call to 'sort(std::_List_iterator<int>, std::_List_iterator<int>)' But instead I TONS of other errors.