id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
4853,Actor is never assignable regardless of the template parameter,Neil Groves,Hartmut Kaiser,"On November 3, a user reported an issue using multiple Boost.Range adaptors upon a sequence. He produced code similar to this:

struct Foo
{
     Foo(const std::string& name, int value) : name_(name), value_(value)
       {
       }

       std::string name_;
       int value_;
};

typedef boost::shared_ptr<Foo> FooPtr;

int range_test_complex()
{
       typedef std::vector<FooPtr> V;

       V source;
       source +=
               boost::make_shared<Foo>(""Foo"", 10),
               boost::make_shared<Foo>(""Bar"", 20),
               boost::make_shared<Foo>(""Baz"", 30),
               boost::make_shared<Foo>(""Baz"", 30)      // duplicate is here
               ;

       std::vector<std::string> result1;
       std::vector<int> result2;

       using namespace boost::adaptors;
       using phx::arg_names::arg1;

       boost::push_back(result1, source | transformed(phx::bind(&Foo::name_, *arg1)) | uniqued); // Fails

       boost::push_back(result2, source | transformed(phx::bind(&Foo::value_, *arg1)) | uniqued); // Fails

       return 0;
}

I investigated the issue and found that replacing the bind expressions solved the problem. The issue appears to have been introduced in revision 57503 by a change intended to remove a warning about being unable to generate the assignment operator. I confirmed with the user that by commenting out line 143 in boost/spirit/home/pheonix/core/actor.hpp that the code compiled and worked as expected.

Hence I believe that revision 57503 had the unintended consequence of making the actors non-assignable when they should be assignable.",Bugs,closed,Boost 1.49.0,spirit,Boost Release Branch,Regression,fixed,actor assignable,