Wrap VariableIndex.at(), .empty()

gtsam/inference/VariableIndex.cpp

@@ -23,6 +23,24 @@ namespace gtsam {
 
 using namespace std;
 
+const FactorIndices& operator[](Key variable) const {
+  KeyMap::const_iterator item = index_.find(variable);
+}
+
+const FactorIndices& at(Key variable) const {
+  KeyMap::const_iterator item = (*this)[variable];
+  if(item == index_.end())
+    throw std::invalid_argument("Requested non-existent variable '" +
+                                DefaultKeyFormatter(variable) +
+                                "' from VariableIndex");
+  else
+    return item->second;
+}
+
+bool empty(Key variable) const {
+  return (*this)[variable].empty();
+}
+
 /* ************************************************************************* */
 bool VariableIndex::equals(const VariableIndex& other, double tol) const {
   return this->nEntries_ == other.nEntries_ && this->nFactors_ == other.nFactors_

gtsam/inference/VariableIndex.h

@@ -84,20 +84,12 @@ class GTSAM_EXPORT VariableIndex {
   size_t nEntries() const { return nEntries_; }
 
   /// Access a list of factors by variable
-  const FactorIndices& operator[](Key variable) const {
+  const FactorIndices& operator[](Key variable) const;
-    KeyMap::const_iterator item = index_.find(variable);
+
-    if(item == index_.end())
+  const FactorIndices& at(Key variable) const;
-      throw std::invalid_argument("Requested non-existent variable '" +
-                                  DefaultKeyFormatter(variable) +
-                                  "' from VariableIndex");
-    else
-      return item->second;
-  }
 
   /// Return true if no factors associated with a variable
-  bool empty(Key variable) const {
+  bool empty(Key variable) const;
-    return (*this)[variable].empty();
-  }
 
   /// @}
   /// @name Testable

gtsam/inference/inference.i

@@ -199,6 +199,9 @@ class VariableIndex {
   VariableIndex(const T& factorGraph);
   VariableIndex(const gtsam::VariableIndex& other);
 
+  const FactorIndices& at(Key variable) const;
+  bool empty(Key variable) const;
+
   // Testable
   bool equals(const gtsam::VariableIndex& other, double tol) const;
   void print(string s = "VariableIndex: ",