phoenix block statement tries to copy objects instead of references

[armagvvg@…]

Let's use a simplest class, that can't be copied:

class A {
   A() {}
   A(const A&);
public:
   static A* construct() { return new A(); }
   const A& operator<<(const char *p) const { return *this; }
};

A *pa = A::construct();
A &a = *pa;

The code which use this object one time normally works:

(boost::phoenix::ref(a) << boost::phoenix::placeholders::_1)("aaa");

But when I try to use this object two times, I get an error:

(
   boost::phoenix::ref(a) << boost::phoenix::placeholders::_1
   ,boost::phoenix::ref(a) << boost::phoenix::placeholders::_1
)("aaa");

Result: 'A::A' : cannot access private member declared in class 'A'

Expecting: pass compilation and invoke "A::operator<<" two times.

Note: preprocessing directive "BOOST_SPIRIT_USE_PHOENIX_V3" was defined.

[Kohei Takahashi]

Confirmed in C++03 mode. ​http://melpon.org/wandbox/permlink/UZtPeYVO11Ad3EG3

In C++11, it works: ​http://melpon.org/wandbox/permlink/x6k6rOMUbepDgkBh