Namespace Aliases

A namespace alias is a way to give a shorter or more convenient name to a namespace. You create a namespace alias using the namespace keyword followed by the alias name and an = sign.

For example:

1#include <iostream>
2
3namespace VeryLongNamespace {
4  void Foo() {
5    std::cout << "VeryLongNamespace::Foo()\n";
6  }
7}
8
9namespace VLN = VeryLongNamespace;  
10
11int main() {
12  VLN::Foo();  
13}

1VeryLongNamespace::Foo()

Here, VLN is an alias for VeryLongNamespace. We can use VLN::Foo() instead of VeryLongNamespace::Foo().

You would use a namespace alias:

1. To make your code more readable by shortening long namespace names.
2. To avoid typing out long namespace names repeatedly.
3. To create a shorter name for a nested namespace.

For example:

1namespace A::B::C {
2  void Foo() {}
3}
4
5namespace ABC = A::B::C;
6
7int main() {
8  ABC::Foo();
9}