提高:: shared_ptr的 <const T> to boost :: shared_ptr <T>

Question

I want to cast the const-ness out of a boost::shared_ptr , but I boost::const_pointer_cast is not the answer. boost::const_pointer_cast wants a const boost::shared_ptr<T> , not a boost::shared_ptr<const T> . Let's forego the obligatory "you shouldn't be doing that". I know... but I need to do it... so what's the best/easiest way to do it?

For clarity sake:

boost::shared_ptr<const T> orig_ptr( new T() );

boost::shared_ptr<T> new_ptr = magic_incantation(orig_ptr);

I need to know the magic_incantation()

Answer 1

boost::const_pointer_cast is the function you want to use:

boost::shared_ptr<const int> ci(new int(42));
boost::shared_ptr<int> i(boost::const_pointer_cast<int>(ci));

Does that not work for you? I tested that with both Boost 1.43 and the Visual C++2010 C++0x implementation--no issues with either.

Answer 2

请注意，至少可以说，如果共享的const T突然改变，其他“股东”会非常惊讶 ......