Mastering C++ Programming

Easier nested namespace syntax

Until the C++14 standard, the syntax supported for a nested namespace in C++ was as follows:

#include <iostream>using namespace std;namespace org {    namespace tektutor {        namespace application {             namespace internals {                  int x;             }        }    }}int main ( ) {    org::tektutor::application::internals::x = 100;    cout << "\nValue of x is " << org::tektutor::application::internals::x << endl;    return 0;}

The preceding code can be compiled and the output can be viewed with the following commands:

g++-7 main.cpp -std=c++17./a.out

The output of the preceding program is as follows:

Value of x is 100

Every namespace level starts and ends with curly brackets, which makes it difficult to use nested namespaces in large applications. C++17 nested ...