The iostream.h header was provided with the first C++ compiler, CFront, and became the de facto standard. During the formal
standardization process of C++, many shortcomings in iostream.h were fixed, but at the cost of introducing incompatibilities. Therefore,
it was decided not to change the existing iostream.h and introduce the standard version as a new iostream header.
Modern compilers tend to remove the support of the legacy iostream.h header, and migrating to the standard version is encouraged.
This rule applies not only to iostream, but to all standard C++ headers.
Noncompliant code example
#include <iostream.h> // Noncompliant
#include <fstream.h> // Noncompliant
Compliant solution
#include <iostream>
#include <fstream>
