error C2280 - attempting to reference a deleted function

[Unspoken]

Hi guys,

this piece of code

struct Test
{
  Test() {};
  Test(const Test&) = delete;
  Test& operator=(const Test&) = delete;
};
int main(int argc, char* argv[])
{
  std::vector<Test> tests;
  tests.push_back(std::move(Test())); //gives error here

  return 0;
}

gives me error: error C2280: 'Test::Test(const Test &)': attempting to reference a deleted function

I know that I've explicitely deleted copy constructor, but I thought I could move instance of Test() to vector insteasd of copying it. What am I doing wrong? How to move Test() to vector?

Thank you.

[Unspoken]

I think I understand it now.

Deleting copy constructor explicitely caused compiler to not generate move constructor.
So calling std::move(Test()) does not call move constructor because there is no one.

But in that case, shouldn't compiler inform me that move constructor is missing?

[Peter87]

That's right. If you want the compiler to generate the move constructor and the move assignment operator you'll need to say so explicitly.

struct Test
{
  Test() {};
  Test(const Test&) = delete;
  Test& operator=(const Test&) = delete;
  Test(Test&&) = default;
  Test& operator=(Test&&) = default;
};

[JLBorges]

> But in that case, shouldn't compiler inform me that move constructor is missing?

If only the copy constructor is provided, all argument categories select it (as long as it takes a reference to const, since rvalues can bind to const references), which makes copying the fallback for moving, when moving is unavailable.

https://en.cppreference.com/w/cpp/language/move_constructor

[Unspoken]

Thanks guys.