Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is an older version of Boost and was released in 2013. The current version is 1.90.0.

ip::icmp::operator!=

Compare two protocols for inequality.

friend bool operator!=(
    const icmp & p1,
    const icmp & p2);