c ++ 14中unique_ptr和shared_ptr语法之间的区别

Question

我想知道c ++ 14中unique_ptr和shared_ptr之间的差异如下所示。

示例程序（http://ideone.com/A4As5B）：

#include <memory>

int main() {
    std::unique_ptr<unsigned char[]> ptr1 = std::unique_ptr<unsigned char[]>(new unsigned char[10]);
    std::shared_ptr<unsigned char[]> ptr2 = std::shared_ptr<unsigned char[]>(new unsigned char[10]);
    return 0;
}

给出了这个编译错误：

Compilation error   time: 0 memory: 0 signal:0
In file included from /usr/include/c++/6/bits/shared_ptr.h:52:0,
                 from /usr/include/c++/6/memory:82,
                 from prog.cpp:2:
/usr/include/c++/6/bits/shared_ptr_base.h: In instantiation of ‘std::__shared_ptr<_Tp, _Lp>::__shared_ptr(_Tp1*) [with _Tp1 = unsigned char; _Tp = unsigned char []; __gnu_cxx::_Lock_policy _Lp = (__gnu_cxx::_Lock_policy)2u]’:
/usr/include/c++/6/bits/shared_ptr.h:117:32:   required from ‘std::shared_ptr<_Tp>::shared_ptr(_Tp1*) [with _Tp1 = unsigned char; _Tp = unsigned char []]’
prog.cpp:6:96:   required from here
/usr/include/c++/6/bits/shared_ptr_base.h:885:39: error: cannot convert ‘unsigned char*’ to ‘unsigned char (*)[]’ in initialization
         : _M_ptr(__p), _M_refcount(__p)
                                       ^

我的问题是，为什么数组分配的unique_ptr语法使其成为c ++ 14，但对于shared_ptr，我们必须等到c ++ 17？两个智能指针之间是否有任何概念上的差异，当为unique_ptr指定时，这使得非直接指定share_ptr？