unordered_flat_map does not support non-copyable types?

[luinx]

#include "robin_hood.h"
#include <string>

class A {
private:
  std::string x;
public:
  A() = delete;
  A& operator=(const A& other) = delete;
  A(A&& other) : x(std::move(other.x)){}
  explicit A(std::string x) : x(std::move(x)) {}
};

int main(int argc, char** argv) {
  robin_hood::unordered_flat_map<std::string, A> m;
  m.emplace("ok", "hi");
  return 0;
}

From the document it seems the choice over flat map and node map is from memory concerns, otherwise, they can be used interchangeably. But the above code just can't compile in flat map mode. only unordered_map works.

[martinus]

Hi, your class needs to be move constructible, and also needs move assignable. Add this method, then it should work:

    A& operator=(A&& other) {
        mVal = std::move(other.mVal);
        return *this;
    }