How to get user define move constructor called

  1 #include <iostream>
  2 #include <cstdlib>
  3
  4 using namespace std;
  5
  6 class c
  7 {
  8     public:
  9         c(){ cout << "Default ctor" << endl; }
 10         c(const c& o) { cout << "Copy ctor" << endl; }
 11         c(c&& o){ cout << "move copy ctor" << endl; }
 12         //c(c&& o)=delete;
 13         ~c() { cout << "Destructor" << endl; }
 14 };
 15
 16 int main()
 17 {
 18     c o = c();
 19     c p = std::move(c());
 20     return 0;
 21 }

This piece of code produces the below output.

Default ctor
Default ctor
move copy ctor
Destructor
Destructor
Destructor

However, if I deactivate line#11 and activate line#12 then it gives below compile time error.

prog.cc: In function 'int main()':
prog.cc:18:13: error: use of deleted function 'c::c(c&&)'
   18 |     c o = c();
      |             ^
prog.cc:12:9: note: declared here
   12 |         c(c&& o)=delete;
      |         ^

which implies that, line#18 invokes the move copy constructor provided by compiler. How to get my user defined move constructor in line#11 invoked without using std::move?

Or std::move is the only way to get user defined move constructors invoked?