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 2023. The current version is 1.90.0.

optional

optional

The type of optional used by the library.

Synopsis

Defined in header <boost/url/optional.hpp>

template<
    class T>
using optional = boost::optional< T >;

Convenience header <boost/url.hpp>