poly/isnothrowmovable.cpp

The following code example is taken from the book
C++ Move Semantics - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2020
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

// raw code

#include "isnothrowmovable.hpp"
#include <iostream>

class Base {
  std::string id;
  //...
public:
  virtual void print() const = 0;  // pure virtual function (forces abstract base class)
  //...
  virtual ~Base() = default;
protected:
  // protected copy and move semantics (also forces abstract base class):
  Base(const Base&) = default;
  Base(Base&&) = default;
  // disable assignment operator (due to the problem of slicing):
  Base& operator= (Base&&) = delete;
  Base& operator= (const Base&) = delete;
};

int main()
{
  std::cout << std::boolalpha;
  std::cout << "std::is_nothrow_move_constructible_v<Base>: "
            << std::is_nothrow_move_constructible_v<Base> << '\n';
  std::cout << "is_nothrow_movable_v<Base>:                 "
            << is_nothrow_movable_v<Base> << '\n';
}