make config.h accessible to projects using loadleveller

src/MersenneTwister.h

-#ifndef MCL_SINGLE
 #include "mpi.h"
-#endif
 #include <cassert>
+#include <vector>
+#include <cstring>
 
 // MersenneTwister.h
 // Mersenne Twister random number generator -- a C++ class MTRand

src/meson.build

@@ -8,7 +8,10 @@ conf_data = configuration_data()
 conf_data.set('rng_backend', rng_names[get_option('rng_backend')])
 configure_file(input : 'config.h.in',
   output : 'config.h',
+  install : should_install,
+  install_dir : 'include/loadleveller',
   configuration : conf_data)
+config_inc = include_directories('.')
 
 loadleveller_sources = files([
   'dump.cpp',
@@ -60,7 +63,7 @@ if should_install
 endif
 
 loadleveller_dep = declare_dependency(
-  include_directories : include_directories('../include/'),
+  include_directories : [ include_directories('../include/'), config_inc ],
   link_with : libloadleveller,
   dependencies : loadleveller_deps,
   version : meson.project_version(),