c++ - 无法从 'initializer-list' 转换为 UserController

Question

我有这门课:

class UserController
{
private:
    Repo repo;
    Repo adoption;
public:
    UserController(const Repo& r, const Repo& a) : repo(r), adoption(a) {}

    Dog get(int index) { return this->repo.get(index); };
};

当我尝试创建一个 UserController 类型的对象时，如下所示:

UserController controller{ repo1, repo2 };

它给了我错误:“error C2440: 'initializing' : cannot convert from 'initializer-list' to 'UserController'”。为什么？

Answer 1

你需要c++11编译这段代码。

下面我在没有 C++11 支持和有(成功)的情况下进行编译。

Georgioss-MacBook-Pro:~ gsamaras$ g++ main.cpp 
main.cpp:14:20: error: no matching constructor for initialization of
      'UserController'
    UserController controller{ repo1, repo2 };
                   ^
main.cpp:2:7: note: candidate constructor (the implicit copy constructor) not
      viable: requires 1 argument, but 0 were provided
class UserController
      ^
main.cpp:8:5: note: candidate constructor not viable: requires 2 arguments, but
      0 were provided
    UserController(const Repo& r, const Repo& a) : repo(r), adoption(a) {}
    ^
main.cpp:14:30: error: expected ';' at end of declaration
    UserController controller{ repo1, repo2 };
                             ^
                             ;
2 errors generated.
Georgioss-MacBook-Pro:~ gsamaras$ g++ -std=c++0x main.cpp 
Georgioss-MacBook-Pro:~ gsamaras$