isprime14.hpp

The following code example is taken from the book
C++ Templates - The Complete Guide, 2nd Edition
by David Vandevoorde, Nicolai M. Josuttis, and Douglas Gregor,
Addison-Wesley, 2017
© Copyright David Vandevoorde, Nicolai M. Josuttis, Douglas Gregor 2017


constexpr bool isPrime (unsigned int p)
{
  for (unsigned int d=2; d<=p/2; ++d) {
    if (p % d == 0) {
      return false;  // found divisor without remainder
    }
  }
  return p > 1;      // no divisor without remainder found
}