add OpenCut() constructor of SimpleCut (always passed)

Author: lubynets

infra/SimpleCut.cpp

@@ -45,6 +45,10 @@ SimpleCut EqualsCut(const Variable& var, int value, const std::string& title) {
   return SimpleCut(var, value, title);
 }
 
+SimpleCut OpenCut(const std::string& branchName, const std::string& title) {
+  return SimpleCut({branchName + ".ones"}, [](const std::vector<double>& par) { return true; });
+}
+
 SimpleCut::SimpleCut(const Variable& var, int value, std::string title) : title_(std::move(title)) {
   vars_.emplace_back(var);
   lambda_ = [value](std::vector<double>& vars) { return vars[0] <= value + SmallNumber && vars[0] >= value - SmallNumber; };

infra/SimpleCut.hpp

@@ -83,6 +83,14 @@ class SimpleCut {
   */
   friend SimpleCut EqualsCut(const Variable& var, int value, const std::string& title);
 
+  /**
+  * Constructor for a cut which is always passed
+  * (needed for keeping generality of the user's code, when a set of cuts
+  * is iterated and an iteration with no-cut is needed)
+  * @param branchName name of the branch, which is present in other cuts
+  */
+  friend SimpleCut OpenCut(const std::string& branchName, const std::string& title);
+
   /**
    * @brief Evaluates cut
    * @tparam T type of data-object associated with TTree
@@ -131,6 +139,7 @@ SimpleCut RangeCut(const std::string& variable_name, double lo, double hi, const
 SimpleCut EqualsCut(const std::string& variable_name, int value, const std::string& title = "");
 SimpleCut RangeCut(const Variable& var, double lo, double hi, const std::string& title = "");
 SimpleCut EqualsCut(const Variable& var, int value, const std::string& title = "");
+SimpleCut OpenCut(const std::string& branchName, const std::string& title = "alwaysTrue");
 
 }// namespace AnalysisTree
 #endif//ANALYSISTREE_SIMPLECUT_H