Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I’m looking through an API written in C++ and I’m confused as to what the following parameter type means:
void*& data
Does that mean the user would pass in a reference to a void pointer? If that’s true, what’s the point? I mean void* is already indirected so why would you ever want to redirect it again?
It’s tough to say without seeing it’s use, but you point out that a reference is a level of indirection. Would you find it weird if it was a pointer to a pointer? Those are quite common – in fact you deal with them when accepting command line arguments and get pointers to char pointers. Another example would be if you were making a hash map using buckets, and wanted to be able to return the pointer to the pointer that started the bucket.
The point being is that sometimes you need multiple levels of indirection. It is true that mixing pointers and references can be quirky, but there are good reasons for it. One common reason is the need for C++ code to interact with C apis. A lot of POSIX system calls require void pointers that get passed in and then changed, so the C++ function in question may be acting as a wrapper around that.