title: Can std::array be used in a constexpr class?
body: <p>I am currently creating a class with a <code>constexpr</code> constructor and I wonder if I can use an <code>std::array</code> to store the data of this class. Does the standard explicitly specify that an <code>std::array</code> has a <code>constexpr</code> constructor and that its contents can be accessed at compile-time ?</p>