namespaces.md

Namespaces

• Namespaces are a mechanism in C++ for organizing code and avoiding naming conflicts. Their main purposes include providing scope, organizing code, and preventing name collisions.

• C++ supports nested namespace definitions. Use the :: operator to access identifiers in different namespaces.

• The using keyword simplifies namespace usage by bringing a namespace or specific identifier into the current scope.

• Avoid using namespace in header files, as it affects all code that includes that header. Also avoid using namespace in global scope, as it easily causes naming conflicts.

• Best practice: use specific using declarations in source files, or use using namespace within function scope:

  // 1. Use specific using declarations in source files
  using std::cout;
  using std::endl;
  using std::vector;
  
  // 2. Or use using namespace within function scope
  void function() {
      using namespace std;
      cout << "Safe to use here" << endl;
  }