added power of two warning

mlmc/src/Main.cpp

 #include "m++.hpp"
 #include "Main.hpp"
 
+
 #ifdef COMPLEX
 #error undef COMPLEX in src/Compiler.h
 #endif
 
 int main(int argc, char **argv) {
-    Config::setSearchPath("../mlmc/");
-    Config::setConfigFileName("m++.conf");
-    Mpp::initialize(&argc, argv);
+  Config::setSearchPath("../mlmc/");
+  Config::setConfigFileName("m++.conf");
+  Mpp::initialize(&argc, argv);
+
+  if(!PowerOfTwo(PPM->Size(0))) {
+    Warning("Number of process is not a power of 2."
+            "This might lead to undefined behaviour.")
+  }
 
-    MainProgram mainProgram;
-    return mainProgram.Run();
+  MainProgram mainProgram;
+  return mainProgram.Run();
 }

mlmc/src/Main.hpp

@@ -4,6 +4,12 @@
 #include "montecarlo/MultilevelMonteCarlo.hpp"
 
 
+
+bool PowerOfTwo(int n) {
+  if(n==0) return false;
+  return (ceil(log2(n)) == floor(log2(n)));
+}
+
 class MainProgram {
 private:
   int verbose = 1;