VC2013 移动运算符不递归执行移动

Question

以下代码无法在 VS2013 中编译。

#include <memory>
#include <vector>

struct Struct {
  std::unique_ptr<int> data;
};

int main() {
  std::vector<Struct> vec;
  vec.emplace_back();
  vec.emplace_back();
  vec.front() = std::move(vec.back());
  return 0;
}

我收到以下错误：

error C2280: attempting to reference a deleted function

似乎 VS 编译器试图在代码明确请求移动时调用赋值运算符。这是一个错误吗？这个问题有什么解决方法吗？

Answer 1

VS2013 不会自动生成所需的构造函数。

"Rvalue references v3.0" adds new rules to automatically generate move constructors and move assignment operators under certain conditions. However, this is not implemented in Visual C++ in Visual Studio 2013, due to time and resource constraints.

所以为了编译程序，你必须至少实现这些构造函数：

struct Struct {
  std::unique_ptr<int> data;

  Struct() { }

  // For exposition purposes only, change as needed
  Struct(Struct&& o) : data(std::move(o.data)) {}

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

似乎在Microsoft's online compiler, though中实现了。

VC2013 移动运算符不递归执行移动

VC2013 move operator doesn't recursively perform move

c++

move-semantics

visual-studio-2013