Boost failed when build with permissive- + MSVC on windows.

[QuellaZhang]

Boost failed with error C3646, C4430, C3861 when build with permissive- on Windows, I use latest source on master branch. Could you please help take a look at this? Noted that this issue only found when compiles with unreleased vctoolset, that next release of MSVC will have this behavior.

You can repro this issue as the steps below:

1. git clone -c core.autocrlf=true --recursive https://github.com/boostorg/boost.git D:\Boost\src
2. Open a VS 2015 x86 command prompt and browse to D:\Boost\src
3. .\bootstrap
4. .\b2 headers variant=release --build-dir=..\out\Release --address-model=32
5. .\b2 variant=release --build-dir=..\out\Release --address-model=32

Error info: .\boost/range/concepts.hpp(257): error C3646: 'n': unknown override specifier .\boost/range/concepts.hpp(264): note: see reference to class template instantiation 'boost::range_detail::RandomAccessIteratorConcept' being compiled .\boost/range/concepts.hpp(257): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int .\boost/range/concepts.hpp(247): error C3861: 'n': identifier not found .\boost/range/concepts.hpp(248): error C3861: 'n': identifier not found .\boost/range/concepts.hpp(249): error C3861: 'n': identifier not found .\boost/range/concepts.hpp(250): error C3861: 'n': identifier not found .\boost/range/concepts.hpp(251): error C3861: 'n': identifier not found .\boost/range/concepts.hpp(252): error C3861: 'n': identifier not found

[vinniefalco]

I'm having this problem with the release version of MSVC.

[DanielaE]

This is a duplicate of issue #66