解引用共享指针并分配给它

Question

Is it ok to dereference a shared pointer, assign and assign a new object to it like so:

void foo()
{
    std::shared_ptr<std::string> x =
            std::make_shared<std::string>();

    bar(*x); // is this fine?
    // x == bsl::string("WHATEVER")
}

void bar(string& y)
{
    y = string("whatever");
}

Answer 1

Yes, this is valid. Operator * returns the result of dereferencing the stored (raw) pointer.

Dereferencing a (raw) pointer does not make a copy or return a temporary: dereferencing a pointer when passing by reference

Answer 2

It is fine to do it but I would use the shared_ptr::get() operator in order to be more obvious regarding the fact that we are not using a raw pointer.

void foo()
{
    std::shared_ptr<std::string> sharedPtr = std::make_shared<std::string>();
    bar(*sharedPtr.get());
}