What are universal references in C++11?

Can you explain what universal references are in C++11?

Sure! Universal references in C++11 refer to a type of reference that can bind to both lvalues and rvalues. They are typically declared using the syntax T&& where T is a template type.

How do universal references differ from rvalue references?

Great question! Rvalue references are a specific case of universal references. While rvalue references can only bind to rvalues, universal references can bind to both lvalues and rvalues depending on the context.

Can you give me an example of how to use universal references?

Certainly! Here's a simple example:

template <typename T>
void process(T&& arg) {
    // arg is a universal reference
}

In this function, arg can accept both lvalues and rvalues.

What are the benefits of using universal references?

The main benefits include perfect forwarding, which allows you to forward arguments to other functions without losing their value category, and improved performance by avoiding unnecessary copies.