Question

我在VS2013中遇到以下代码时出错......

class Bob
{
private:
    std::vector<std::unique_ptr<UnrelatedClass>> _aVector;
    inline Bob(const Bob & other) {};
    inline Bob & operator=(const Bob & other) { return *this; };
public:
    Bob();
    ~Bob();
    Bob(Bob && o);
};

class Fred
{
    friend class Bob;

    [... A few functions, Bob never used ...]
};

...通过删除friend class Bob;编译得很好。这是编译错误吗？我不确定我做错了什么。

错误如下：

c:\program files (x86)\microsoft visual studio 12.0\vc\include\xmemory0(615): error C2248: 'std::unique_ptr<Unrelated,std::default_delete<_Ty>>::unique_ptr' : cannot access private member declared in class 'std::unique_ptr<Unrelated,std::default_delete<_Ty>>'
      with
      [
          _Ty=Unrelated
      ]
      c:\program files (x86)\microsoft visual studio 12.0\vc\include\memory(1487) : see declaration of 'std::unique_ptr<Unrelated,std::default_delete<_Ty>>::unique_ptr'
      with
      [
          _Ty=Unrelated
      ]
      c:\program files (x86)\microsoft visual studio 12.0\vc\include\xmemory0(614) : while compiling class template member function 'void std::allocator<_Ty>::construct(_Ty *,const _Ty &)'
      with
      [
          _Ty=std::unique_ptr<Unrelated,std::default_delete<Unrelated>>
      ]
      c:\program files (x86)\microsoft visual studio 12.0\vc\include\xmemory0(752) : see reference to function template instantiation 'void std::allocator<_Ty>::construct(_Ty *,const _Ty &)' being compiled
      with
      [
          _Ty=std::unique_ptr<Unrelated,std::default_delete<Unrelated>>
      ]
      c:\program files (x86)\microsoft visual studio 12.0\vc\include\type_traits(580) : see reference to class template instantiation 'std::allocator<_Ty>' being compiled
      with
      [
          _Ty=std::unique_ptr<Unrelated,std::default_delete<Unrelated>>
      ]
      c:\program files (x86)\microsoft visual studio 12.0\vc\include\vector(650) : see reference to class template instantiation 'std::is_empty<_Alloc>' being compiled
      with
      [
          _Alloc=std::allocator<std::unique_ptr<Unrelated,std::default_delete<Unrelated>>>
      ]
      c:\...\include\bob.h(51) : see reference to class template instantiation 'std::vector<std::unique_ptr<Unrelated,std::default_delete<_Ty>>,std::allocator<std::unique_ptr<_Ty,std::default_delete<_Ty>>>>' being compiled
      with
      [
          _Ty=Unrelated
      ]

研究让我明白这是复制Bob时产生的错误。因此，复制std::vector，因此复制std::unique_ptr

Answer 1

我找到了解决方案。似乎问题是部分编译器问题，主要是我的错。更新我的编译器会产生一个更好的错误消息，描述使用已删除的函数作为问题的原因。

我将问题追溯到以下一行：

_aVector.push_back(someUniquePtr);

应该是：

_aVector.push_back(std::move(someUniquePtr));

下次我必须更加小心;）

的std ::矢量<性病::的unique_ptr <X>＆GT;导致问题的成员变量</std :: unique_ptr <x>

1 个答案: