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 2024. The current version is 1.90.0.

pct_string_view::const_reference

The const reference type.

using const_reference = char const&;