What Is Rvalue Reference

Rvalue references are introduced in c 11 and rvalue references can do what lvalue references fails to do i e.

What is rvalue reference.

To better distinguish these two types we refer to a traditional c reference as an lvalue reference. Rvalue references is a small technical extension to the c language. Let s play a bit with this new toy. So the following snippet works like a charm.

An rvalue reference is a compound type very similar to c s traditional reference. Checks whether t is a rvalue reference type. Rvalue references allow programmers to avoid logically unnecessary copying and to provide perfect forwarding functions. Rvalue references are a feature of c that was added with the c 11 standard.

A rvalue reference can refer to rvalues. They are primarily meant to aid in the design of higer performance and more robust libraries. Here lvalueref2 is a lvalue reference so it cannot point to a rvalue. It s like removing the const attribute in the second line above.

The behavior of a program that adds specializations for is rvalue reference or is rvalue reference v since c 17 is undefined. C 0x has introduced a new type called rvalue reference denoted by placing a double ampersand after some type. When the term reference is used it refers to both kinds of reference. According to the language specifications you are allowed to bind a const lvalue to an rvalue.

Invalid initialization of non const reference of type int from an rvalue of type int gcc complains about the reference not being const namely a constant. Provides the member constant value which is equal to true if t is a rvalue reference type. To declare a rvalue reference we need to specify two operator i e. Otherwise value is equal to false.

Such rvalue reference lets you modify the value of a temporary object.