C and C++ driver for MongoDB Formula was removed
Last versions were
libmongoclient requires the following formulae to be installed:
scons 3.0.1 Substitute for classic 'make' tool with autoconf/automake functionality
boost 1.66.0 Collection of portable C++ source libraries

Recent formula history

Mike McQuaid mongo-cxx-driver: rename from libmongoclient, cleanup.
ilovezfs libmongoclient 2.6.12
Mike McQuaid Use hash rockets again. (#5177)
Mike McQuaid Use Ruby 1.9+ symbol hash keys in all formulae. (#4942)
Dominyk Tiller libmongoclient 2.6.11

Formula code at GitHub