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 2019. The current version is 1.89.0.

ip::address_v4::to_ulong

Get the address as an unsigned long in host byte order.

unsigned long to_ulong() const;