Compile a gpsd client in C++

Answering in case someone else encounters this issue.

The proper header file to include is, as suggested in the comments:

#include <libgpsmm.h>

pkg-config should then be able to find the proper search path, assuming gpsd (and/or depending on the OS, libgps-dev or variants thereof) is installed.

There's a good gist on github I use as a base for interacting with gpsd clients in C++ here: example c++ gpsd program using libgpsmm

It even has an example compile command (adapt to clang or other if needed):

g++ -Wall -std=c++17 -pedantic $(pkg-config --cflags --libs libgps) gpsd-example.cpp -o gpsd-example