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 2020. The current version is 1.90.0.

test::stream::nread

Return the number of reads.

std::size_t
nread() const;