[Math] Remove TDataPointN class

The only difference between `TDataPoint` and `TDataPointN` was that the
the latter used manually allocated memory, and the first uses stack
arrays with the size given in a template argument.

There is no need to use dynamic allocation then, and it's also not good
for performance if the memory for each datapoint has to be allocated.

Removing the class at this time should still be fine, as the
`TDataPointN` class was only introduced in 2011 (52e7782) and is also
undocumented, untested, and not covered by release notes or tutorials.

Closes the following JIRA ticket:

https://its.cern.ch/jira/browse/ROOT-9323

Author: guitargeek

README/ReleaseNotes/v638/index.md

@@ -4,6 +4,7 @@
 * The `RooStats::HLFactory` class that was deprecated in ROOT 6.36 is now removed. It provided little advantage over using the RooWorkspace directly or any of the other higher-level frameworks that exist in the RooFit ecosystem.
 * The build options `mysql`, `odbc` and `pgsql`, that were deprecated in ROOT 6.36, are now removed.
 * The `TGLWSIncludes.h` header is deprecated and will be removed in ROOT 6.40
+* The `ROOT::Math::TDataPointN` class that can be used with the `ROOT::Math::KDETree` was removed. Use the templated `TDataPoint<N>` instead.
 
 ## Core Libraries
 * Behavior change: when selecting a template instantiation for a dictionary, all the template arguments have to be fully defined - the forward declarations are not enough any more. The error prompted by the dictionary generator will be `Warning: Unused class rule: MyTemplate<MyFwdDeclaredClass>`.

math/mathcore/CMakeLists.txt

@@ -79,7 +79,6 @@ set(HEADERS
   Math/SpecFuncMathCore.h
   Math/StdEngine.h
   Math/TDataPoint.h
-  Math/TDataPointN.h
   Math/TRandomEngine.h
   Math/Types.h
   Math/Util.h

math/mathcore/inc/LinkDef2.h

@@ -183,8 +183,6 @@
 #pragma link C++ class ROOT::Math::TDataPoint<1,Double_t>+;
 #pragma link C++ typedef ROOT::Math::TDataPoint1F;
 #pragma link C++ typedef ROOT::Math::TDataPoint1D;
-#pragma link C++ class  ROOT::Math::TDataPointN<Double_t>+;
-#pragma link C++ class  ROOT::Math::TDataPointN<Float_t>+;
 //
 //N.B. use old streamer (do not use +) for KDTree class because it will not work on Windows
 // to work one would need to change the internal classes from private to public

math/mathcore/inc/Math/TDataPointN.h

@@ -149,17 +149,17 @@ int execTypedefList() {
    // res = check_target("std::list<std::string>::const_iterator","list<string>::const_iterator"); if (res) return res;
 
 #if defined(_MSC_VER)
-   res = check_file("typelist_win32.v5.txt",336); if (res) return res;
+   res = check_file("typelist_win32.v5.txt",334); if (res) return res;
    #if __cplusplus > 201402L
       res = check_file("typelist_win32.v6.cxx17.txt",1408); if (res) return res;
    #else
       res = check_file("typelist_win32.v6.txt",1420); if (res) return res;
    #endif
 #elif defined(R__MACOSX) && __cplusplus > 201402L
-   res = check_file("typelist.v5.txt",336); if (res) return res;
+   res = check_file("typelist.v5.txt",334); if (res) return res;
    res = check_file("typelist.v6.cxx17.txt",1310); if (res) return res;
 #else   
-   res = check_file("typelist.v5.txt",336); if (res) return res;
+   res = check_file("typelist.v5.txt",334); if (res) return res;
    res = check_file("typelist.v6.txt",1322); if (res) return res;
 #endif
 

roottest/root/meta/execTypedefList.C

@@ -68,7 +68,6 @@ TKDTreeID
 basic_ios<char,char_traits<char> >::traits_type
 Short_t
 TKDTreeIF
-ROOT::Math::TDataPointN<double>::value_type
 basic_stringbuf<char,char_traits<char>,allocator<char> >::pos_type
 Version_t
 basic_ifstream<char,char_traits<char> >::char_type
@@ -180,7 +179,6 @@ vector<string,allocator<string> >::reference
 vector<TString,allocator<TString> >::const_pointer
 vector<double,allocator<double> >::const_iterator
 string::pointer
-ROOT::Math::TDataPointN<float>::value_type
 TColorGradient::SizeType_t
 vector<string,allocator<string> >::iterator::reference
 vector<double,allocator<double> >::difference_type

roottest/root/meta/typelist.v5.txt

@@ -68,7 +68,6 @@ TKDTreeID
 basic_ios<char,char_traits<char> >::traits_type
 Short_t
 TKDTreeIF
-ROOT::Math::TDataPointN<double>::value_type
 basic_stringbuf<char,char_traits<char>,allocator<char> >::pos_type
 Version_t
 basic_ifstream<char,char_traits<char> >::char_type
@@ -179,7 +178,6 @@ vector<string,allocator<string> >::reference
 vector<TString,allocator<TString> >::const_pointer
 vector<double,allocator<double> >::const_iterator
 string::pointer
-ROOT::Math::TDataPointN<float>::value_type
 TColorGradient::SizeType_t
 vector<string,allocator<string> >::iterator::reference
 vector<double,allocator<double> >::difference_type