问题
Is it possible to extract a raw pointer from a std::shared_ptr or std::tr1::shared_ptr object? The intent is to tell the smart pointer object that I don't want it to manage the lifetime of the object anymore. The context is that I have an API that takes a raw pointer from users and does some processing on the object. To make things easier to manage API creates a shared_ptr out of this raw pointer. Now, the user might ask for the object to be returned. In that case, when giving the processed object back to the user I want to give back the raw pointer. However, I have not found a way to do that. Using .get() is not possible as then the smart pointer will have to be kept alive indefinitely. I would have given back a unique_ptr but that is not available in tr1.
Basically I want to move the raw pointer out of the shared_ptr.
回答1:
I think you are searching for the method release() of shared_ptr. Sorry - there is no such method by design.
Here I found a funny way to do what you want - https://stackoverflow.com/a/13701773/233885.
You should think about using shared_ptr again in you context (ownership).
来源：https://stackoverflow.com/questions/22962991/extracting-a-raw-pointer-from-a-shared-ptr