Create error.hpp

[youngtack]

make.cmd complains about this file and zero size file resolves it.

[lauracaulfield]

I think there's something odd in your setup -- when I run make.cmd (in src\precondition) in a VS2015 command prompt there's no error. The changes you made in the other pull requests shouldn't affect this code.

[youngtack]

## Even make.cmd of the latest version on VS2015, which is from master.zip, complains as below.

C:\StorScore-0408-2016\src\precondition>make.cmd

C:\StorScore-0408-2016\src\precondition>cl /EHsc /O2 /GL /I. precondition.cpp
Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23918 for x86
Copyright (C) Microsoft Corporation.  All rights reserved.

precondition.cpp
Unknown compiler version - please run the configure tests and report the results

.\boost/preprocessor/repetition/repeat.hpp(19): fatal error C1083: Cannot open include file: 'boost/preprocessor/debug/error.hpp': No such file or directory

[bdenison99]

I've run into this same issue. I just created /boost/preprocessor/debug/error.hpp as an empty file, and it works around the issue.

[marksantaniello]

Laura, you should probably compare compiler versions to see what's going on here ("VS2015" is perhaps not enough, run cl.exe /Bv).

Boost includes a lot of work-arounds for different compilers. The "Unknown compiler version" message is a clue. Now that VS2015 is out, we may want to just update to a newer version of Boost that is "VS2015 aware".

I don't like the idea of sticking an empty error.hpp file somewhere. We should get the proper files from Boost included.