与boost_ptr结合的boost ptr_vector错误

Question

I'm trying to get rid of auto_ptr from my code. But im getting this error, and don't know why?

no matching function for call to 'boost::ptr_vector<a>::push_back(std::remove_reference<std::unique_ptr<a>&>::type)'
note: candidates are:
...
note: 'std::unique_ptr<a>' is not derived from 'std::auto_ptr<T>'

{
    boost::ptr_vector<a>& c;

    std::unique_ptr<a> b( new a(x, y) );

    if (!b->isValid())
        return;
    c.push_back(std::move(a));
}

Answer 1

It's exactly what the error message tells you: boost::ptr_vector::push_back expects an auto_ptr , but you provide a unique_ptr , which can not be converted to auto_ptr .

Since you are converting to std::unique_ptr , you won't need boost::ptr_vector any more, since it was only meant as a workaround for auto_ptr , which could not be stored in containers. Instead use std::vector<std::unique_ptr<T>> .