C++ How to Program, 10/e

... not explicitly used the inline keyword. Today’s optimizing compilers are so sophisticated that it’s best to leave inlining decisions to the compiler.

Figure 6.16 uses inline function cube (lines 9–11) to calculate the volume of a cube. Keyword const in function cube’s parameter list (line 9) tells the compiler that the function does not modify variable side. This ensures that side’s value is not changed by the function during the calculation. (Keyword const is discussed in additional detail in Chapters 7–9.)

Software Engineering Observation 6.8

The const qualifier should be used to enforce the principle of least privilege. Using this principle to ...