boost::none compile errors with MSVC

[raad@…]

The new boost::none in 1.58 doesn't compile on MSVC when using precomiled headers.

Code to reproduce the problem:

precompiled header stdafx.h:

#include <boost/optional.hpp>

s.cpp:

#include "stdafx.h"

struct s {
 void f(boost::optional<int> const& = boost::none) {}
};

On MSVC12, this results in the error message:

s.cpp(3): error C3083: ' ?? A0x06d21c56': the symbol to the left of a '::' must be a type

Defining BOOST_OPTIONAL_USE_OLD_DEFINITION_OF_NONE works around the problem, but I haven't found it documented anywhere.