[Bug c++/37172] New: g++ should not cast const iterator to non-const by default

["nilmonid at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following c++ source file compiled by gcc without any warnings/errors with
the flags "-c -W -Wall" ->

// -------------------- start -----------------------
#include<string>
#include<set>
using namespace std;

class A0
{
public:
    typedef set<int> Groups;
    typedef Groups::const_iterator ConstIterator;
    typedef Groups::iterator            Iterator;
public:
    ConstIterator get() const { return values.begin(); }
    Iterator      get()       { return values.begin(); }
private:
    Groups values;
};

class A1
{
public:
    A1(A0* b) : a(b) {}
    void f1() { A0::ConstIterator itr = a->get(); }
    void g1() { A0::Iterator      itr = a->get(); }  // error with vc++ 8.0
private:
    const A0 *a;
};
// -------------------- end -----------------------

However, the same code causes visual c++ 8.0 (visual studio 2005) to report
compilation error in the function g1() since it refuses to cast a const
iterator to non-const by default.

It seems that the behavior of gcc is incorrect and vc++ 8.0 is doing the right
thing since in the function g1(), the const pointer 'a' is only allowed to
invoke the const version of A0::get() which in turn would return a const
iterator. Unfortunately, gcc is automatically casting the returned const
iterator to a non-const iterator.


-- 
           Summary: g++ should not cast const iterator to non-const by
                    default
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: nilmonid at gmail dot com
 GCC build triplet: x86


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37172