--- trunk/src/utils/OpenMDBitSet.cpp	2010/05/10 17:28:26	1442
+++ branches/development/src/utils/OpenMDBitSet.cpp	2013/02/20 15:39:39	1850
@@ -35,16 +35,21 @@
  *                                                                      
  * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).             
  * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).          
- * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008).          
- * [4]  Vardeman & Gezelter, in progress (2009).                        
+ * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008).          
+ * [4]  Kuang & Gezelter,  J. Chem. Phys. 133, 164101 (2010).
+ * [5]  Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011).
  */
 
 #include <algorithm>
 #include <cassert>
 #include <string>
+#include <iterator>
 
 #include "utils/OpenMDBitSet.hpp"
 #include "utils/Algorithm.hpp"
+#ifdef IS_MPI
+#include <mpi.h>
+#endif
 
 namespace OpenMD {
   int OpenMDBitSet::countBits() {
@@ -63,8 +68,8 @@ namespace OpenMD {
     assert(fromIndex <= toIndex);
     assert(fromIndex >=0);
     assert(toIndex <= size());
-    std::vector<char>::iterator first = bitset_.begin() + fromIndex;
-    std::vector<char>::iterator last = bitset_.begin() + toIndex;
+    std::vector<bool>::iterator first = bitset_.begin() + fromIndex;
+    std::vector<bool>::iterator last = bitset_.begin() + toIndex;
 
     std::transform(first, last, first, std::logical_not<bool>());
         
@@ -74,8 +79,8 @@ namespace OpenMD {
     assert(fromIndex <= toIndex);
     assert(fromIndex >=0);
     assert(toIndex <= size());
-    std::vector<char>::iterator first = bitset_.begin() + fromIndex;
-    std::vector<char>::iterator last = bitset_.begin() + toIndex;
+    std::vector<bool>::iterator first = bitset_.begin() + fromIndex;
+    std::vector<bool>::iterator last = bitset_.begin() + toIndex;
 
     OpenMDBitSet result;
     std::copy(first, last, std::back_inserter(result.bitset_));
@@ -83,7 +88,7 @@ namespace OpenMD {
   }
 
   bool OpenMDBitSet::none() {
-    std::vector<char>::iterator i = std::find(bitset_.begin(), bitset_.end(), true);
+    std::vector<bool>::iterator i = std::find(bitset_.begin(), bitset_.end(), true);
     return i == bitset_.end() ? true : false;
   }
     
@@ -141,8 +146,8 @@ namespace OpenMD {
     assert(fromIndex <= toIndex);
     assert(fromIndex >=0);
     assert(toIndex <= size());
-    std::vector<char>::iterator first = bitset_.begin() + fromIndex;
-    std::vector<char>::iterator last = bitset_.begin() + toIndex;
+    std::vector<bool>::iterator first = bitset_.begin() + fromIndex;
+    std::vector<bool>::iterator last = bitset_.begin() + toIndex;
     std::fill(first, last, value);
   }
 
@@ -189,6 +194,34 @@ namespace OpenMD {
   bool operator== (const OpenMDBitSet & bs1, const OpenMDBitSet &bs2) {
     assert(bs1.size() == bs2.size());
     return std::equal(bs1.bitset_.begin(), bs1.bitset_.end(), bs2.bitset_.begin());
+  }  
+
+  OpenMDBitSet OpenMDBitSet::parallelReduce() {
+    OpenMDBitSet result;
+
+#ifdef IS_MPI
+
+    // This is necessary because std::vector<bool> isn't really a
+    // std::vector, so we can't pass the address of the first element
+    // to the MPI call that follows.  We first have to convert to a
+    // std::vector<int> to do the logical_or Allreduce call, then back
+    // convert it into the vector<bool>.
+
+    std::vector<int> bsInt(bitset_.begin(), bitset_.end());
+
+    MPI::COMM_WORLD.Allreduce(MPI::IN_PLACE, &bsInt[0], 
+                              bsInt.size(), MPI::INT, MPI::LOR);
+
+    std::transform(bsInt.begin(), bsInt.end(), 
+                   std::back_inserter( result.bitset_ ), to_bool<int>());
+#else
+
+    // Not in MPI?  Just return a copy of the current bitset:
+    std::copy(bitset_.begin(), bitset_.end(), 
+              std::back_inserter( result.bitset_ ));
+#endif
+
+    return result;
   }
 
   //std::istream& operator>> ( std::istream& is, const OpenMDBitSet& bs) {
@@ -197,7 +230,7 @@ namespace OpenMD {
   //}
 
   std::ostream& operator<< ( std::ostream& os, const OpenMDBitSet& bs) {
-    for (int i = 0; i < bs.bitset_.size(); ++i) {
+    for (unsigned int i = 0; i < bs.bitset_.size(); ++i) {
       std::string val = bs[i] ? "true" : "false";
       os << "OpenMDBitSet[" << i <<"] = " << val << std::endl; 
     }