c cannot use mutex along with vector

I have trouble compiling the following code.

#include <vector>
#include <mutex>


class A
{
public:
  A(){}
private:
  std::mutex a_mutex;
};


int main()
{
   std::vector<A> v;
   A a;
   v.push_back(a);
   return 0;
}

This is the error.

$ g++ test__use_of_deleted_function.cpp
In file included from /usr/include/c++/8/x86_64-redhat-linux/bits/c++allocator.h:33,
                 from /usr/include/c++/8/bits/allocator.h:46,
                 from /usr/include/c++/8/string:41,
                 from test__use_of_delete_function.cpp:1:
/usr/include/c++/8/ext/new_allocator.h: In instantiation of ‘void __gnu_cxx::new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up = A; _Args = {const A&}; _Tp = A]’:
/usr/include/c++/8/bits/alloc_traits.h:475:4:   required from ‘static void std::allocator_traits<std::allocator<_CharT> >::construct(std::allocator_traits<std::allocator<_CharT> >::allocator_type&, _Up*, _Args&& ...) [with _Up = A; _Args = {const A&}; _Tp = A; std::allocator_traits<std::allocator<_CharT> >::allocator_type = std::allocator<A>]’
/usr/include/c++/8/bits/stl_vector.h:1079:30:   required from ‘void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = A; _Alloc = std::allocator<A>; std::vector<_Tp, _Alloc>::value_type = A]’
test__use_of_delete_function.cpp:19:17:   required from here
/usr/include/c++/8/ext/new_allocator.h:136:4: error: use of deleted function ‘A::A(const A&)’
  { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test__use_of_delete_function.cpp:6:7: note: ‘A::A(const A&)’ is implicitly deleted because the default definition would be ill-formed:
 class A
       ^
test__use_of_delete_function.cpp:6:7: error: use of deleted function ‘std::mutex::mutex(const std::mutex&)’
In file included from /usr/include/c++/8/mutex:43,
                 from test__use_of_delete_function.cpp:3:
/usr/include/c++/8/bits/std_mutex.h:97:5: note: declared here
     mutex(const mutex&) = delete;
     ^~~~~
In file included from /usr/include/c++/8/vector:62,
                 from test__use_of_delete_function.cpp:2:
/usr/include/c++/8/bits/stl_construct.h: In instantiation of ‘void std::_Construct(_T1*, _Args&& ...) [with _T1 = A; _Args = {A}]’:
/usr/include/c++/8/bits/stl_uninitialized.h:83:18:   required from ‘static _ForwardIterator std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = std::move_iterator<A*>; _ForwardIterator = A*; bool _TrivialValueTypes = false]’
/usr/include/c++/8/bits/stl_uninitialized.h:134:15:   required from ‘_ForwardIterator std::uninitialized_copy(_InputIterator, _InputIterator, _ForwardIterator) [with _InputIterator = std::move_iterator<A*>; _ForwardIterator = A*]’
/usr/include/c++/8/bits/stl_uninitialized.h:289:37:   required from ‘_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, std::allocator<_Tp>&) [with _InputIterator = std::move_iterator<A*>; _ForwardIterator = A*; _Tp = A]’
/usr/include/c++/8/bits/stl_uninitialized.h:311:2:   required from ‘_ForwardIterator std::__uninitialized_move_if_noexcept_a(_InputIterator, _InputIterator, _ForwardIterator, _Allocator&) [with _InputIterator = A*; _ForwardIterator = A*; _Allocator = std::allocator<A>]’
/usr/include/c++/8/bits/vector.tcc:447:6:   required from ‘void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp, _Alloc>::iterator, _Args&& ...) [with _Args = {const A&}; _Tp = A; _Alloc = std::allocator<A>; std::vector<_Tp, _Alloc>::iterator = __gnu_cxx::__normal_iterator<A*, std::vector<A> >; typename std::_Vector_base<_Tp, _Alloc>::pointer = A*]’
/usr/include/c++/8/bits/stl_vector.h:1085:4:   required from ‘void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = A; _Alloc = std::allocator<A>; std::vector<_Tp, _Alloc>::value_type = A]’
test__use_of_delete_function.cpp:19:17:   required from here
/usr/include/c++/8/bits/stl_construct.h:75:7: error: use of deleted function ‘A::A(A&&)’
     { ::new(static_cast<void*>(__p)) _T1(std::forward<_Args>(__args)...); }
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test__use_of_delete_function.cpp:6:7: note: ‘A::A(A&&)’ is implicitly deleted because the default definition would be ill-formed:
 class A
       ^
test__use_of_delete_function.cpp:6:7: error: use of deleted function ‘std::mutex::mutex(const std::mutex&)’
In file included from /usr/include/c++/8/mutex:43,
                 from test__use_of_delete_function.cpp:3:
/usr/include/c++/8/bits/std_mutex.h:97:5: note: declared here
     mutex(const mutex&) = delete;
     ^~~~~