The following instructions compile without any warning; tested using g++ 2.95, 3.3 and 3.4: std::set<int> vs; const std::set<int>::const_iterator i = vs.begin(); vs.erase(i); it should stop compilation with an error, such as: " error: invalid conversion from `const int* const' to `int*' "
No, the code is OK. A const iterator cannot be used to directly modify the container, but you can pass it to erase() without any problems.
Also FYI notice that iterators are almost *never* implemented as raw pointers (they are objects which implements operator* and operator-> and acts like pointers).
*** Bug 17374 has been marked as a duplicate of this bug. ***
The standard doesn't mention set::erase with "iterator" argument, only with "const_iterator". Maybe it is legal for g++ to allow it anyway (even if I cannot find anything in the standard allowing it at the moment), but other compilers don't, so it is a rather useless extension. So I'll reopen this bug.
(In reply to comment #4) > The standard doesn't mention set::erase with "iterator" argument, only with > "const_iterator". erm. the other way round, of course.
template<class _Key, class _Compare, class _Alloc> class set { ... // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 103. set::iterator is required to be modifiable, // but this allows modification of keys. typedef typename _Rep_type::const_iterator iterator; typedef typename _Rep_type::const_iterator const_iterator; typedef typename _Rep_type::const_reverse_iterator reverse_iterator; typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; all iterators are const...
Yes, we are simply implementing the resolution of DR 103: set<>::iterator is a constant iterator type