[RF] Use new RooStringView in RooFit dataset classes

This has two advantages over `std::string_view`:

 1. We don't need preporcessor macros and branches to support ROOT's
    std::string_view backport for C++14.
 2. The `std::string_view` was not appropriate anyway, because in the
    `TNamed` constructor the strig had to be copied anyway to guarantee
    the string is null-terminated. With `RooStringView` we don't have
    this problem: it is guaranteed to be null-terminated.

Author: guitargeek

roofit/roofit/src/RooLagrangianMorphFunc.cxx

@@ -833,7 +833,7 @@ void collectHistograms(const char *name, TDirectory *file, std::map<std::string,
          RooArgSet vars;
          vars.add(var);
 
-         RooDataHist *dh = new RooDataHist(histname.View(), histname.View(), vars, hist);
+         RooDataHist *dh = new RooDataHist(histname, histname, vars, hist);
          // add it to the list
          RooHistFunc *hf = new RooHistFunc(funcname, funcname, var, *dh);
          int idx = physics.getSize();

roofit/roofitcore/inc/RooAbsData.h

@@ -23,7 +23,6 @@
 #include "RooSpan.h"
 #include "RooNameReg.h"
 
-#include "ROOT/RStringView.hxx"
 #include "TNamed.h"
 
 #include <map>
@@ -57,37 +56,14 @@ struct ConstantTermsOptimizer;
 }
 
 
-// Writes a templated constructor for compatibility with ROOT builds using the
-// C++14 standard or earlier, taking `ROOT::Internal::TStringView` instead of
-// `std::string_view`. This means one can still use a `TString` for the name or
-// title parameter. The condition in the following `#if` should be kept in
-// sync with the one in TString.h.
-#if (__cplusplus >= 201700L) && !defined(_MSC_VER) && (!defined(__clang_major__) || __clang_major__ > 5)
-#define WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(Class_t) // does nothing
-#else
-#define WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(Class_t)                                             \
-  template<typename ...Args_t>                                                                    \
-  Class_t(ROOT::Internal::TStringView name, ROOT::Internal::TStringView title, Args_t &&... args) \
-    : Class_t(std::string_view(name), std::string_view(title), std::forward<Args_t>(args)...) {}  \
-  template<typename ...Args_t>                                                                    \
-  Class_t(ROOT::Internal::TStringView name, std::string_view title, Args_t &&... args)            \
-    : Class_t(std::string_view(name), title, std::forward<Args_t>(args)...) {}                    \
-  template<typename ...Args_t>                                                                    \
-  Class_t(std::string_view name, ROOT::Internal::TStringView title, Args_t &&... args)            \
-    : Class_t(name, std::string_view(title), std::forward<Args_t>(args)...) {}
-#endif
-
-
 class RooAbsData : public TNamed, public RooPrintable {
 public:
 
   // Constructors, factory methods etc.
   RooAbsData() ; 
-  RooAbsData(std::string_view name, std::string_view title, const RooArgSet& vars, RooAbsDataStore* store=0) ;
+  RooAbsData(RooStringView name, RooStringView title, const RooArgSet& vars, RooAbsDataStore* store=0) ;
   RooAbsData(const RooAbsData& other, const char* newname = 0) ;
 
-  WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(RooAbsData)
-
   RooAbsData& operator=(const RooAbsData& other);
   virtual ~RooAbsData() ;
   virtual RooAbsData* emptyClone(const char* newName=0, const char* newTitle=0, const RooArgSet* vars=0, const char* wgtVarName=0) const = 0 ;

roofit/roofitcore/inc/RooAbsDataStore.h

@@ -38,8 +38,8 @@ class RooAbsDataStore : public TNamed, public RooPrintable {
 public:
 
   RooAbsDataStore() {}
-  RooAbsDataStore(std::string_view name, std::string_view title, const RooArgSet& vars)
-    : TNamed(TString{name},TString{title}), _vars{vars} {}
+  RooAbsDataStore(RooStringView name, RooStringView title, const RooArgSet& vars)
+    : TNamed(name,title), _vars{vars} {}
   RooAbsDataStore(const RooAbsDataStore& other, const char* newname=0)
     : RooAbsDataStore(other, other._vars, newname) {}
   RooAbsDataStore(const RooAbsDataStore& other, const RooArgSet& vars, const char* newname=0)
@@ -48,8 +48,6 @@ class RooAbsDataStore : public TNamed, public RooPrintable {
     if(newname) SetName(newname);
   }
 
-  WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(RooAbsDataStore)
-
   virtual RooAbsDataStore* clone(const char* newname=0) const = 0 ;
   virtual RooAbsDataStore* clone(const RooArgSet& vars, const char* newname=0) const = 0 ;
 

roofit/roofitcore/inc/RooCompositeDataStore.h

@@ -37,9 +37,7 @@ class RooCompositeDataStore : public RooAbsDataStore {
   RooCompositeDataStore() ; 
 
   // Ctors from DataStore
-  RooCompositeDataStore(std::string_view name, std::string_view title, const RooArgSet& vars, RooCategory& indexCat, std::map<std::string,RooAbsDataStore*> inputData) ;
-
-  WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(RooCompositeDataStore)
+  RooCompositeDataStore(RooStringView name, RooStringView title, const RooArgSet& vars, RooCategory& indexCat, std::map<std::string,RooAbsDataStore*> inputData) ;
 
   // Empty ctor
   virtual RooAbsDataStore* clone(const char* newname=0) const { return new RooCompositeDataStore(*this,newname) ; }

roofit/roofitcore/inc/RooDataHist.h

@@ -47,18 +47,16 @@ class RooDataHist : public RooAbsData, public RooDirItem {
 
   // Constructors, factory methods etc.
   RooDataHist() ; 
-  RooDataHist(std::string_view name, std::string_view title, const RooArgSet& vars, const char* binningName=0) ;
-  RooDataHist(std::string_view name, std::string_view title, const RooArgSet& vars, const RooAbsData& data, Double_t initWgt=1.0) ;
-  RooDataHist(std::string_view name, std::string_view title, const RooArgList& vars, const TH1* hist, Double_t initWgt=1.0) ;
-  RooDataHist(std::string_view name, std::string_view title, const RooArgList& vars, RooCategory& indexCat, std::map<std::string,TH1*> histMap, Double_t initWgt=1.0) ;
-  RooDataHist(std::string_view name, std::string_view title, const RooArgList& vars, RooCategory& indexCat, std::map<std::string,RooDataHist*> dhistMap, Double_t wgt=1.0) ;
+  RooDataHist(RooStringView name, RooStringView title, const RooArgSet& vars, const char* binningName=0) ;
+  RooDataHist(RooStringView name, RooStringView title, const RooArgSet& vars, const RooAbsData& data, Double_t initWgt=1.0) ;
+  RooDataHist(RooStringView name, RooStringView title, const RooArgList& vars, const TH1* hist, Double_t initWgt=1.0) ;
+  RooDataHist(RooStringView name, RooStringView title, const RooArgList& vars, RooCategory& indexCat, std::map<std::string,TH1*> histMap, Double_t initWgt=1.0) ;
+  RooDataHist(RooStringView name, RooStringView title, const RooArgList& vars, RooCategory& indexCat, std::map<std::string,RooDataHist*> dhistMap, Double_t wgt=1.0) ;
   //RooDataHist(const char *name, const char *title, const RooArgList& vars, Double_t initWgt=1.0) ;
-  RooDataHist(std::string_view name, std::string_view title, const RooArgList& vars, const RooCmdArg& arg1, const RooCmdArg& arg2=RooCmdArg(), const RooCmdArg& arg3=RooCmdArg(),
+  RooDataHist(RooStringView name, RooStringView title, const RooArgList& vars, const RooCmdArg& arg1, const RooCmdArg& arg2=RooCmdArg(), const RooCmdArg& arg3=RooCmdArg(),
         const RooCmdArg& arg4=RooCmdArg(),const RooCmdArg& arg5=RooCmdArg(),const RooCmdArg& arg6=RooCmdArg(),const RooCmdArg& arg7=RooCmdArg(),const RooCmdArg& arg8=RooCmdArg()) ;
   RooDataHist& operator=(const RooDataHist&) = delete;
 
-  WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(RooDataHist)
-
   RooDataHist(const RooDataHist& other, const char* newname = 0) ;
   TObject* Clone(const char* newname="") const override {
     return new RooDataHist(*this, newname && newname[0] != '\0' ? newname : GetName());
@@ -246,7 +244,7 @@ class RooDataHist : public RooAbsData, public RooDirItem {
   void setAllWeights(Double_t value) ;
 
   void initialize(const char* binningName=0,Bool_t fillTree=kTRUE) ;
-  RooDataHist(std::string_view name, std::string_view title, RooDataHist* h, const RooArgSet& varSubset, 
+  RooDataHist(RooStringView name, RooStringView title, RooDataHist* h, const RooArgSet& varSubset,
         const RooFormulaVar* cutVar, const char* cutRange, Int_t nStart, Int_t nStop, Bool_t copyCache) ;
   RooAbsData* reduceEng(const RooArgSet& varSubset, const RooFormulaVar* cutVar, const char* cutRange=0, 
                   std::size_t nStart=0, std::size_t nStop=std::numeric_limits<std::size_t>::max(), Bool_t copyCache=kTRUE) override;

roofit/roofitcore/inc/RooDataSet.h

@@ -46,28 +46,26 @@ class RooDataSet : public RooAbsData, public RooDirItem {
   RooDataSet() ; 
 
   // Empty constructor 
-  RooDataSet(std::string_view name, std::string_view title, const RooArgSet& vars, const char* wgtVarName=0) ;
+  RooDataSet(RooStringView name, RooStringView title, const RooArgSet& vars, const char* wgtVarName=0) ;
 
   // Universal constructor
-  RooDataSet(std::string_view name, std::string_view title, const RooArgSet& vars, const RooCmdArg& arg1, const RooCmdArg& arg2=RooCmdArg(), 
+  RooDataSet(RooStringView name, RooStringView title, const RooArgSet& vars, const RooCmdArg& arg1, const RooCmdArg& arg2=RooCmdArg(),
 	     const RooCmdArg& arg3=RooCmdArg(), const RooCmdArg& arg4=RooCmdArg(),const RooCmdArg& arg5=RooCmdArg(),
 	     const RooCmdArg& arg6=RooCmdArg(),const RooCmdArg& arg7=RooCmdArg(),const RooCmdArg& arg8=RooCmdArg()) ; 
 
     // Constructor for subset of existing dataset
-  RooDataSet(std::string_view name, std::string_view title, RooDataSet *data, const RooArgSet& vars, 
+  RooDataSet(RooStringView name, RooStringView title, RooDataSet *data, const RooArgSet& vars,
              const char *cuts=0, const char* wgtVarName=0);
-  RooDataSet(std::string_view name, std::string_view title, RooDataSet *data, const RooArgSet& vars,  
+  RooDataSet(RooStringView name, RooStringView title, RooDataSet *data, const RooArgSet& vars,
 	     const RooFormulaVar& cutVar, const char* wgtVarName=0) ;  
 
 
   // Constructor importing data from external ROOT Tree
-  RooDataSet(std::string_view name, std::string_view title, TTree *tree, const RooArgSet& vars,
+  RooDataSet(RooStringView name, RooStringView title, TTree *tree, const RooArgSet& vars,
 	     const char *cuts=0, const char* wgtVarName=0); 
-  RooDataSet(std::string_view name, std::string_view title, TTree *tree, const RooArgSet& vars,
+  RooDataSet(RooStringView name, RooStringView title, TTree *tree, const RooArgSet& vars,
 	     const RooFormulaVar& cutVar, const char* wgtVarName=0) ;  
 
-  WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(RooDataSet)
-
   RooDataSet(RooDataSet const & other, const char* newname=0) ;  
   virtual TObject* Clone(const char* newname = "") const override {
     return new RooDataSet(*this, newname && newname[0] != '\0' ? newname : GetName());
@@ -159,7 +157,7 @@ class RooDataSet : public RooAbsData, public RooDirItem {
   // Cache copy feature is not publicly accessible
   RooAbsData* reduceEng(const RooArgSet& varSubset, const RooFormulaVar* cutVar, const char* cutRange=0, 
 	                std::size_t nStart=0, std::size_t nStop = std::numeric_limits<std::size_t>::max(), Bool_t copyCache=kTRUE) override;
-  RooDataSet(std::string_view name, std::string_view title, RooDataSet *ntuple, 
+  RooDataSet(RooStringView name, RooStringView title, RooDataSet *ntuple,
 	     const RooArgSet& vars, const RooFormulaVar* cutVar, const char* cutRange, std::size_t nStart, std::size_t nStop, Bool_t copyCache, const char* wgtVarName=0);
 
   RooArgSet addWgtVar(const RooArgSet& origVars, const RooAbsArg* wgtVar) ; 

roofit/roofitcore/inc/RooTreeDataStore.h

@@ -38,22 +38,20 @@ class RooTreeDataStore : public RooAbsDataStore {
   RooTreeDataStore() ; 
   RooTreeDataStore(TTree* t, const RooArgSet& vars, const char* wgtVarName=0) ; 
 
-  WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(RooTreeDataStore)
-
   // Empty ctor
-  RooTreeDataStore(std::string_view name, std::string_view title, const RooArgSet& vars, const char* wgtVarName=0) ;
+  RooTreeDataStore(RooStringView name, RooStringView title, const RooArgSet& vars, const char* wgtVarName=0) ;
   virtual RooAbsDataStore* clone(const char* newname=0) const { return new RooTreeDataStore(*this,newname) ; }
   virtual RooAbsDataStore* clone(const RooArgSet& vars, const char* newname=0) const { return new RooTreeDataStore(*this,vars,newname) ; }
 
   // Ctors from TTree
-  RooTreeDataStore(std::string_view name, std::string_view title, const RooArgSet& vars, TTree& t, const RooFormulaVar& select, const char* wgtVarName=0) ; 
-  RooTreeDataStore(std::string_view name, std::string_view title, const RooArgSet& vars, TTree& t, const char* selExpr=0, const char* wgtVarName=0) ; 
+  RooTreeDataStore(RooStringView name, RooStringView title, const RooArgSet& vars, TTree& t, const RooFormulaVar& select, const char* wgtVarName=0) ;
+  RooTreeDataStore(RooStringView name, RooStringView title, const RooArgSet& vars, TTree& t, const char* selExpr=0, const char* wgtVarName=0) ;
 
   // Ctors from DataStore
-  RooTreeDataStore(std::string_view name, std::string_view title, const RooArgSet& vars, const RooAbsDataStore& tds, const RooFormulaVar& select, const char* wgtVarName=0) ;
-  RooTreeDataStore(std::string_view name, std::string_view title, const RooArgSet& vars, const RooAbsDataStore& tds, const char* selExpr=0, const char* wgtVarName=0) ;
+  RooTreeDataStore(RooStringView name, RooStringView title, const RooArgSet& vars, const RooAbsDataStore& tds, const RooFormulaVar& select, const char* wgtVarName=0) ;
+  RooTreeDataStore(RooStringView name, RooStringView title, const RooArgSet& vars, const RooAbsDataStore& tds, const char* selExpr=0, const char* wgtVarName=0) ;
 
-  RooTreeDataStore(std::string_view name, std::string_view title, RooAbsDataStore& tds, 
+  RooTreeDataStore(RooStringView name, RooStringView title, RooAbsDataStore& tds,
 		   const RooArgSet& vars, const RooFormulaVar* cutVar, const char* cutRange,
 		   Int_t nStart, Int_t nStop, Bool_t /*copyCache*/, const char* wgtVarName=0) ;
 
@@ -158,7 +156,7 @@ class RooTreeDataStore : public RooAbsDataStore {
 
   static Int_t _defTreeBufSize ;  
 
-  void createTree(std::string_view name, std::string_view title) ; 
+  void createTree(RooStringView name, RooStringView title) ;
   TTree *_tree ;           // TTree holding the data points
   TTree *_cacheTree ;      //! TTree holding the cached function values
   const RooAbsArg* _cacheOwner ; //! Object owning cache contents

roofit/roofitcore/inc/RooVectorDataStore.h

@@ -43,9 +43,7 @@ class RooVectorDataStore : public RooAbsDataStore {
   RooVectorDataStore() ; 
 
   // Empty ctor
-  RooVectorDataStore(std::string_view name, std::string_view title, const RooArgSet& vars, const char* wgtVarName=0) ;
-
-  WRITE_TSTRING_COMPATIBLE_CONSTRUCTOR(RooVectorDataStore)
+  RooVectorDataStore(RooStringView name, RooStringView title, const RooArgSet& vars, const char* wgtVarName=0) ;
 
   virtual RooAbsDataStore* clone(const char* newname=0) const override { return new RooVectorDataStore(*this,newname) ; }
   virtual RooAbsDataStore* clone(const RooArgSet& vars, const char* newname=0) const override { return new RooVectorDataStore(*this,vars,newname) ; }
@@ -55,7 +53,7 @@ class RooVectorDataStore : public RooAbsDataStore {
   RooVectorDataStore(const RooVectorDataStore& other, const RooArgSet& vars, const char* newname=0) ;
 
 
-  RooVectorDataStore(std::string_view name, std::string_view title, RooAbsDataStore& tds, 
+  RooVectorDataStore(RooStringView name, RooStringView title, RooAbsDataStore& tds,
 		     const RooArgSet& vars, const RooFormulaVar* cutVar, const char* cutRange,
 		     std::size_t nStart, std::size_t nStop, Bool_t /*copyCache*/, const char* wgtVarName=0) ;
 
@@ -68,7 +66,7 @@ class RooVectorDataStore : public RooAbsDataStore {
 
     template<class T>
     struct ArrayInfo {
-        ArrayInfo(std::string_view n, T const* d) : name{n}, data{d} {}
+        ArrayInfo(RooStringView n, T const* d) : name{n}, data{d} {}
         std::string name;
         T const* data;
     };

roofit/roofitcore/src/RooAbsData.cxx

@@ -183,8 +183,8 @@ RooAbsData::RooAbsData()
 /// Constructor from a set of variables. Only fundamental elements of vars
 /// (RooRealVar,RooCategory etc) are stored as part of the dataset
 
-RooAbsData::RooAbsData(std::string_view name, std::string_view title, const RooArgSet& vars, RooAbsDataStore* dstore) :
-  TNamed(TString{name},TString{title}),
+RooAbsData::RooAbsData(RooStringView name, RooStringView title, const RooArgSet& vars, RooAbsDataStore* dstore) :
+  TNamed(name,title),
   _vars("Dataset Variables"),
   _cachedVars("Cached Variables"),
   _dstore(dstore),

roofit/roofitcore/src/RooCompositeDataStore.cxx

@@ -61,7 +61,7 @@ RooCompositeDataStore::RooCompositeDataStore() : _indexCat(0), _curStore(0), _cu
 /// Convert map by label to map by index for more efficient internal use
 
 RooCompositeDataStore::RooCompositeDataStore(
-        std::string_view name, std::string_view title,
+        RooStringView name, RooStringView title,
         const RooArgSet& vars, RooCategory& indexCat,map<std::string,RooAbsDataStore*> inputData) :
   RooAbsDataStore(name,title,RooArgSet(vars,indexCat)), _indexCat(&indexCat), _curStore(0), _curIndex(0), _ownComps(kFALSE)
 {