What Is Rvalue Reference

To declare a rvalue reference we need to specify two operator i e.

What is rvalue reference.

A rvalue reference can refer to rvalues. Otherwise value is equal to false. Lvalue reference and rvalue reference. 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.

What makes rvalue references a bit difficult to grasp is that when you first look at them it is not clear what their purpose is or what problems they solve. An rvalue reference is a compound type very similar to c s traditional reference. Such rvalue reference lets you modify the value of a temporary object. According to the language specifications you are allowed to bind a const lvalue to an rvalue.

Const int ref 10. Here lvalueref2 is a lvalue reference so it cannot point to a rvalue. Provides the member constant value which is equal to true if t is a rvalue reference type. The behavior of a program that adds specializations for is rvalue reference or is rvalue reference v since c 17 is undefined.

Rvalue references is a small technical extension to the c language. It s like removing the const attribute in the second line above. To better distinguish these two types we refer to a traditional c reference as an lvalue reference. C 0x has introduced a new type called rvalue reference denoted by placing a double ampersand after some type.

Let s play a bit with this new toy. Checks whether t is a rvalue reference type. When the term reference is used it refers to both kinds of reference. Rvalue references are a feature of c that was added with the c 11 standard.

So the following snippet works like a charm.