excessive includes in isotropy.hpp

[maliberty]

Why are there so many includes in isotropy.hpp that aren't required by this header:

//external
#include <cmath>
#include <cstddef>
#include <cstdlib>
#include <vector>
#include <deque>
#include <map>
#include <set>
#include <list>
//#include <iostream>
#include <algorithm>
#include <limits>
#include <iterator>
#include <string>

I just want the types defined here without getting 55k lines of preprocessed headers.