Compile issue, "unique_ptr" not defined

[markyoder]

Specifically, when I run the "make" step of the build process, I get:

src/TwoBit/IO/TwoBitFile.hpp:131:14: error: ‘unique_ptr’ in namespace ‘std’ does not name a template type
  131 |         std::unique_ptr<TwoBitSequence> operator[](const std::string& s) const;
      |              ^~~~~~~~~~
src/TwoBit/IO/TwoBitFile.hpp:23:1: note: ‘std::unique_ptr’ is defined in header ‘<memory>’; did you forget to ‘#include <memory>’?
   22 | #include <boost/filesystem.hpp>
  +++ |+#include <memory>
   23 | #include <string>
src/TwoBit/IO/TwoBitFile.cpp:153:33: error: no declaration matches ‘std::unique_ptr<TwoBit::TwoBitSequence> TwoBit::TwoBitFile::operator[](const std::string&) const’
  153 | std::unique_ptr<TwoBitSequence> TwoBitFile::operator[](const std::string& s) const
      |                                 ^~~~~~~~~~
src/TwoBit/IO/TwoBitFile.cpp:153:33: note: no functions named ‘std::unique_ptr<TwoBit::TwoBitSequence> TwoBit::TwoBitFile::operator[](const std::string&) const’
src/TwoBit/IO/TwoBitFile.hpp:37:7: note: ‘class TwoBit::TwoBitFile’ defined here
   37 | class TwoBitFile
      |       ^~~~~~~~~~
make: *** [build/TwoBitBuild/src/TwoBit/IO/TwoBitFile.o] Error 1

As the helper suggests (and so do some StackOverflow posts), adding #include into the header file (.hpp) fixes the problem.

[markyoder]

Also, in setup.py... This one took me a while. Because of the other build requirements, I am building dependent SW in MPI mode, and so had my MPI compilers loaded into the CC and CXX variables. Ok,maybe bad form -- we should have CC=gcc MPICC=mpicc, etc. but this is research code, right?

Anyway, in that configuration, the logic in setup.py -- which uses a logic like, if g++ in $CXX..., skips over setting a build command string for boost_filesystem. I fixed that by just setting my compiler variables, but it took me a while; some more robust logic in setup.py would be much appreciated!