PS C:\ROOT\test> rootcint eventdict.cxx -c TEvent.h TTrack.h In file included from input_line_3:2: In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\string:11: In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\xstring:14: In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\xmemory:16: In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\xutility:15: C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\utility:135:9: error: expected member name or ';' after declaration specifiers !conjunction_v<_Is_implicitly_default_constructible<_Uty1>, _Is_implicitly_default_constructible<_Uty2>>) ^ C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\utility:135:9: error: expected ')' C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\utility:134:23: note: to match this '(' constexpr explicit( ^ C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\utility:216:24: error: expected member name or ';' after declaration specifiers constexpr explicit(!conjunction_v, is_convertible>) ~~~~~~~~~~~~~~~~~~ ^ C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\utility:216:24: error: expected ')' C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\utility:216:23: note: to match this '(' constexpr explicit(!conjunction_v, is_convertible>) ^ In file included from input_line_3:2: In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\string:11: In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\xstring:14: In file included from C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\xmemory:16: C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\xutility:67:31: error: '_To' does not refer to a value return __builtin_bit_cast(_To, _Val); ^ C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Tools\MSVC\14.28.29333\include\xutility:57:17: note: declared here template