fixed warnings

src/cltools/Driver.cpp

@@ -915,7 +915,7 @@ int Driver<real>::main(FILE* in,FILE*out,Communicator& pc) {
         p.cmd("GREX shareAllDeltaBias");
         for(int i=0; i<n; i++) {
           string s; Tools::convert(i,s);
-          real a; s="GREX getDeltaBias "+s; p.cmd(s.c_str(),&a);
+          real a=NAN; s="GREX getDeltaBias "+s; p.cmd(s.c_str(),&a);
           if(grex_log) fprintf(grex_log," %f",a);
         }
         if(grex_log) fprintf(grex_log,"\n");

src/tools/Communicator.cpp

@@ -224,12 +224,13 @@ MPI_Comm & Communicator::Get_comm() {
 }
 
 bool Communicator::initialized() {
-  int flag=false;
 #if defined(__PLUMED_HAS_MPI)
+  int flag=0;
   MPI_Initialized(&flag);
-#endif
   if(flag) return true;
   else return false;
+#endif
+  return false;
 }
 
 void Communicator::Request::wait(Status&s) {

src/tools/Exception.h

@@ -172,7 +172,7 @@ public:
     const char*file;
     const unsigned line;
     const char* pretty;
-    Location(const char*file,unsigned line,const char* pretty=nullptr):
+    explicit Location(const char*file,unsigned line,const char* pretty=nullptr):
       file(file),
       line(line),
       pretty(pretty)
@@ -184,7 +184,7 @@ public:
   class Assertion {
   public:
     const char*assertion;
-    Assertion(const char*assertion=nullptr):
+    explicit Assertion(const char*assertion=nullptr):
       assertion(assertion)
     {}
   };