=====namespace=====
Syntax:

<code>
    namespace name {
    declaration-list;
    }
</code>
The namespace keyword allows you to create a new scope. The name is optional,
and can be omitted to create an unnamed namespace. Once you create a namespace,
you'll have to refer to it explicitly or use the using keyword.
Example code:

<code>
     namespace CartoonNameSpace {
       int HomersAge;
       void incrementHomersAge() {
         HomersAge++;
       }
     }
     int main() {
       ...
       CartoonNameSpace::HomersAge = 39;
       CartoonNameSpace::incrementHomersAge();
       cout << CartoonNameSpace::HomersAge << endl;
       ...
     }
</code>

====anonymous namespace====

A namespace without a name called anonymous namespace. For such a namespace, a unique name will be generated for each translation unit. It is not possible to apply the [[using]] keyword to anonymous namespaces, so an anonymous namespace works as if the using keyword has been applied to it.

<code>
    namespace {
    declaration-list;
    }
</code>

====namespace alias====

You can create new names (aliases) for namespaces, including nested namespaces.

<code>
   namespace identifier = namespace-specifier;
</code>

Related Topics: [[using]]