libboost1.71-all-dev 1.71.0-6ubuntu6 (armhf binary) in ubuntu focal

 The Boost web site provides free, peer-reviewed, portable C++ source
 libraries. The emphasis is on libraries which work well with the C++
 Standard Library. One goal is to establish "existing practice" and
 provide reference implementations so that the Boost libraries are
 suitable for eventual standardization. Some of the libraries have
 already been proposed for inclusion in the C++ Standards Committee's
 upcoming C++ Standard Library Technical Report.
 .
 This metapackage provides the complete Boost development environment,
 including all separately-packaged libraries.