False positive with is_copy_constructible on vector

Question

Should the type trait be able to handle cases such as std::vector < std::unique_ptr > and detect that it\'s not copy constructible?

H

Answer 1

Table 49 of the C++11 standard lists what conditions a class has to fulfil for is_copy_constructable::value to be true, and that's unfortunately not much:

is_constructable::value is true

So if std::vector has a copy constructor it passes the test.