Consistent Demangle on MSVC and gcc/clang

Use regex list from here:
https://github.com/RobotLocomotion/drake/blob/master/common/nice_type_name.cc

libsrc/core/utils.cpp

@@ -4,10 +4,45 @@
 #ifndef WIN32
 #include <cxxabi.h>
 #endif
+#include <array>
 #include <iostream>
+#include <regex>
 
 namespace ngcore
 {
+    namespace detail
+    {
+        // see https://github.com/RobotLocomotion/drake/blob/master/common/nice_type_name.cc
+        static const auto demangle_regexes =
+            std::array<std::pair<std::regex, std::string>, 8>{
+                // Remove unwanted keywords and following space. (\b is word boundary.)
+                std::make_pair(std::regex("\\b(class|struct|enum|union) "), ""),
+                // Tidy up anonymous namespace.
+                {std::regex("[`(]anonymous namespace[')]"), "(anonymous)"},
+                // Replace Microsoft __int64 with long long.
+                {std::regex("\\b__int64\\b"), "long long"},
+                // Temporarily replace spaces we want to keep with "!". (\w is
+                // alphanumeric or underscore.)
+                {std::regex("(\\w) (\\w)"), "$1!$2"},
+                {std::regex(" "), ""},  // Delete unwanted spaces.
+                // Some compilers throw in extra namespaces like "__1" or "__cxx11".
+                // Delete them.
+                {std::regex("\\b__[[:alnum:]_]+::"), ""},
+                {std::regex("!"), " "},  // Restore wanted spaces.
+
+                // Recognize std::string's full name and abbreviate.
+                {std::regex("\\bstd::basic_string<char,std::char_traits<char>,"
+                        "std::allocator<char>>"), "std::string"}
+            };
+        std::string CleanupDemangledName( std::string s )
+        {
+            for(const auto & [r, sub] : demangle_regexes)
+                s = std::regex_replace (s,r,sub);
+
+            return s;
+        }
+    } // namespace detail
+
   // parallel netgen
   int id = 0, ntasks = 1;
 
@@ -15,12 +50,7 @@ namespace ngcore
   // windows does demangling in typeid(T).name()
   NGCORE_API std::string Demangle(const char* typeinfo) {
       std::string name = typeinfo;
-      // remove "class " and "struct " at beginning of type names to be consistent with demangled names of gcc/clang
-      if(name.find("class ") == 0)
-          name.erase(0,6);
-      if(name.find("struct ") == 0)
-          name.erase(0,7);
-      return name;
+      return detail::CleanupDemangledName(name);
   }
 #else
   NGCORE_API std::string Demangle(const char* typeinfo)
@@ -31,13 +61,15 @@ namespace ngcore
         char *s = abi::__cxa_demangle(typeinfo, nullptr, nullptr, &status);
         std::string result{s};
         free(s);
+        result = detail::CleanupDemangledName(result);
         return result;
       }
     catch( const std::exception & e )
       {
         GetLogger("utils")->warn("{}:{} cannot demangle {}, status: {}, error:{}", __FILE__, __LINE__, typeinfo, status, e.what());
       }
-    return typeinfo;
+    std::string name = typeinfo;
+    return detail::CleanupDemangledName(name);
   }
 #endif