为什么我不能传递对我的 unique_ptr 的引用？

Question

I have a vector of std::unique_ptr<k_ctrl_t> and I want to pass a reference of the unique_ptr within this vector to another function:

std::vector<std::unique_ptr<k_ctrl_t>> _kitchens;

for (int i = 0; i < (int)_kitchens.size(); i++)
{
    if (FD_ISSET(_kitchens[i]->socket, &this->_readfds))
    {
        handleKitchenRet(std::cref<std::unique_ptr<k_ctrl_t>>(_kitchens[i]));
    }
}

void Reception::handleKitchenRet(std::unique_ptr<k_ctrl_t> kitch)
{
    ...
}

But this doesn't work. How could I do that?

The error message:

error: use of deleted function 'std::unique_ptr<_Tp, _Dp>::unique_ptr(const std::unique_ptr<_Tp, _Dp>&) [with _Tp = kitchen_control_s; _Dp = std::default_delete<kitchen_control_s>]' 
  169 |             handleKitchenRet(std::ref<uKCtrl>(_kitchens[i]));

Answer 1

void Reception::handleKitchenRet(std::unique_ptr<k_ctrl_t> kitch)

is taking a unique_ptr by value .

To take it by reference , change the signature to

void Reception::handleKitchenRet(std::unique_ptr<k_ctrl_t>& kitch)