[boost] [optional] Problem with new boost::none

Subject: [boost] [optional] Problem with new boost::none
From: Marcel Raad (raad_at_[hidden])
Date: 2015-03-21 13:07:50

Hi,

as mentioned in another thread, there are 
compilation problems with the reworked 
none_t on MSVC when using precompiled 
headers.

To reproduce:

precompiled header stdafx.h:
#pragma once
#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