kaeluka · February 27, 2016 13:00 · Feb 27, 2016
diff --git a/moving_unique_ptr.cpp b/moving_unique_ptr.cpp
@@ -0,0 +1,30 @@
+class A {};
+
+// Proof of concept.
+//
+// A class that wraps a unique_ptr and creates a copy constructor that
+// allows you to copy it without the explicit move constructor.
+// The move constructor will be implied. This violates the expectation
+// that copying a value is free of side effects and you should therefore
+// probably not use this class.
+template <class T> struct moving_unique_ptr {
+  moving_unique_ptr(std::unique_ptr<T> _p) : p(move(_p)) { }
+
+  moving_unique_ptr(const moving_unique_ptr &other) {
+    this->p = std::move(const_cast<moving_unique_ptr &>(other).p);
+  }
+private:
+  std::unique_ptr<T> p;
+};
+
+moving_unique_ptr<A> f() { return moving_unique_ptr<A>(std::make_unique<A>()); }
+
+void g(moving_unique_ptr<A> a) {}
+
+int main() {
+  // this works automatically
+  g(f());
+  moving_unique_ptr<A> a = f();
+  // this needs a move
+  g(a);
+}