Gas and Chemical Exposure. NOTE: This is the Consumer Version. Symptoms depend on which gas or chemical is inhaled and how deeply and for how long it was inhaled. Symptoms may include irritation of the eyes or nose, cough, blood in the sputum, and shortness of breath. Chest x-rays, computed tomography, and breathing tests are used to determine how much lung damage has occurred.
Scope refers to the visibility of variables and methods in one part of a program to another part of that program. The importance and meaning of scope varies between languages, but there are two general scope concepts many languages have in common: local and global scope.
This page describes the unary and binary forms of the scope resolution operator in C++. The class construct adds a new set of scope rules to those you are already familiar with in C++. One point of classes is to provide an encapsulation technique. Conceptually, it makes sense that all names declared within a class be treated as if they were in their own namespace, distinct from external names, function names, and other class names. This creates a need for the scope resolution operator (::).