Made Fast* container constructors explicit (like the STL versions) to prevent bugs

gtsam/base/FastList.h

@@ -43,7 +43,7 @@ public:
 
   /** Constructor from a range, passes through to base class */
   template<typename INPUTITERATOR>
-  FastList(INPUTITERATOR first, INPUTITERATOR last) : Base(first, last) {}
+  explicit FastList(INPUTITERATOR first, INPUTITERATOR last) : Base(first, last) {}
 
   /** Copy constructor from another FastList */
   FastList(const FastList<VALUE>& x) : Base(x) {}

gtsam/base/FastMap.h

@@ -44,7 +44,7 @@ public:
 
   /** Constructor from a range, passes through to base class */
   template<typename INPUTITERATOR>
-  FastMap(INPUTITERATOR first, INPUTITERATOR last) : Base(first, last) {}
+  explicit FastMap(INPUTITERATOR first, INPUTITERATOR last) : Base(first, last) {}
 
   /** Copy constructor from another FastMap */
   FastMap(const FastMap<KEY,VALUE>& x) : Base(x) {}

gtsam/base/FastSet.h

@@ -55,7 +55,7 @@ public:
 
   /** Constructor from a range, passes through to base class */
   template<typename INPUTITERATOR>
-  FastSet(INPUTITERATOR first, INPUTITERATOR last) :
+  explicit FastSet(INPUTITERATOR first, INPUTITERATOR last) :
       Base(first, last) {
   }
 

gtsam/base/FastVector.h

@@ -41,14 +41,14 @@ public:
   FastVector() {}
 
   /** Constructor from size */
-  FastVector(size_t size) : Base(size) {}
+  explicit FastVector(size_t size) : Base(size) {}
 
   /** Constructor from size and initial values */
-  FastVector(size_t size, const VALUE& initial) : Base(size, initial) {}
+  explicit FastVector(size_t size, const VALUE& initial) : Base(size, initial) {}
 
   /** Constructor from a range, passes through to base class */
   template<typename INPUTITERATOR>
-  FastVector(INPUTITERATOR first, INPUTITERATOR last) : Base(first, last) {}
+  explicit FastVector(INPUTITERATOR first, INPUTITERATOR last) : Base(first, last) {}
 
   /** Copy constructor from another FastSet */
   FastVector(const FastVector<VALUE>& x) : Base(x) {}