Summary of `const`

const double PI = 3.14159265358979323846;

Defines PI to be a constant, i.e. its value cannot be changed later on.

Point(const Point& p);

While p is passed by reference (immutable pointer) it must not be changed by Point. This permits better performance (as copying is avoided) without sacrificing security.

float get_x() const;

A const following a method signature declares it formally as accessor that is not allowed to change its object.

const Key& get_key();

The caller is not allowed to modify the value which is returned by reference from get_key.

Summary of const

Summary of `const`