shared_ptr class的向量的向量初始化问题

Question

I'm trying to initialize a vector of vector of shared_ptr class of size 19x19 ( _goban ).

class Goban
{
  public:
    Goban();
    ~Goban();
  private:
    vector<vector<shared_ptr<Cell>>> _goban;
};

My constructor is like that:

Goban::Goban() : _goban(18, vector<make_shared<Cell>>(18, new Cell))
{
}

I can't find the way to initialize.

I got this error:

template <class _Tp, class _Allocator /* = allocator<_Tp> */>

Any idea?

Answer 1

You specified the wrong template argument make_shared<Cell> , which should be shared_ptr<Cell> . And note that the implicit conversion from raw pointers to std::shared_ptr is prohibited. Then

Goban::Goban() : _goban(18, vector<shared_ptr<Cell>>(18, make_shared<Cell>()))
//                                 ^^^^^^^^^^^^^^^^      ^^^^^^^^^^^^^^^^^^^
{
}

With the help of deduction guide , you can even omit specifying the template argument as

Goban::Goban() : _goban(18, vector(18, make_shared<Cell>()))
{
}