[boost] boost::aligned_storage broken on VC12 for alignment values of 8

Subject: [boost] boost::aligned_storage broken on VC12 for alignment values of 8
From: Glen Fernandes (glen.fernandes_at_[hidden])
Date: 2014-03-30 02:41:10

Very surprising, but easily reproducible with VC12 (2013), Release or
Debug configuration, Win32 platform: the following program will often*
throw:

    #include <boost/type_traits/aligned_storage.hpp>
    #include <cstdint>
    int main()
    {
        boost::aligned_storage<8, 8>::type a;
        if (((std::uintptr_t)&a % 8) != 0) {
            throw 1;
        }
    }

* Four of every five times it failed because the storage was only
4-byte aligned, not 8-byte aligned.

Does not reproduce for x64 builds, just x86 builds. Does not reproduce
with alignment values other than 8.

Glen