clang++ error message when using C++0x: call to deleted constructor of

Question

Hello I have upgraded my Xcode to version 4.2 and clang++ to version:

Apple clang version 3.0 (tags/Apple/clang-211.10.1) (based on LLVM 3.0svn) 
Target: x86_64-apple-darwin11.2.0
Thread model: posix

When try to compile the following code with clang -std=c++0x

#include <memory>
#include <limits>
#include <boost/shared_ptr.hpp>


class ilpConstraintImpl {
public:
    virtual ~ilpConstraintImpl() {}
};


class ilpConstraint {
public:
    ilpConstraint(ilpConstraintImpl* implptr):impl(implptr) { }
public:
    boost::shared_ptr<ilpConstraintImpl> impl;
};

class ilpExprImpl {
public:
    virtual ilpConstraint operator<= (const double rs)=0;
    virtual ~ilpExprImpl() {}
};



class ilpExpr {
 public:
    virtual ~ilpExpr() {};
    ilpConstraint operator<= (const double rs) { return impl->operator<=(rs); }
    ilpExpr(ilpExprImpl* implptr):impl(implptr) { }
    boost::shared_ptr<ilpExprImpl> impl;
};

I get the following error:

./test.h:46:54: error: call to deleted constructor of 'ilpConstraint'
    ilpConstraint operator<= (const double rs) { return impl->operator<=(rs); }
                                                        ^~~~~~~~~~~~~~~~~~~~
./test.h:28:7: note: function has been explicitly marked deleted here
class ilpConstraint {
      ^
1 error generated.

Compiling without -std=c++0x works.

Answer 1

This looks like a clang bug to me. I'm working with a later clang version which does not have this behavior. You might try giving ilpConstraint an explicit copy constructor as a temporary workaround.