Not able to build with clang-cl

[Neumann-A]

Error:

[6/60] D:\installed\x64-windows\compiler-llvm\bin\clang-cl.exe   -TP -DBOOST_CONTAINER_DYN_LINK -DBOOST_CONTAINER_NO_LIB -DBOOST_DATE_TIME_DYN_LINK -DBOOST_DATE_TIME_NO_LIB -DBOOST_LOG_DYN_LINK -DCPPREST_NO_SSL_LEAK_SUPPRESS -DUNICODE -D_TURN_OFF_PLATFORM_STRING -D_UNICODE -D_WIN32 -Dazurestorage_EXPORTS -ID:\b\azure-storage-cpp\src\v7.5.0-1d01ff61d2.clean\Microsoft.WindowsAzure.Storage\includes -imsvcD:\installed\x64-windows\VS\VC\Tools\MSVC\14.42.34433\include -imsvcD:\installed\x64-windows\VS\VC\Tools\MSVC\14.42.34433\ATLMFC\include -imsvcD:\installed\x64-windows\VS\VC\Auxiliary\VS\include -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\ucrt" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\um" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\shared" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\winrt" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\cppwinrt" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\NETFXSDK\4.8.1\include\um" -imsvcD:\installed\x64-windows-static\include /nologo /DWIN32 /D_WINDOWS -Wno-implicit-function-declaration /utf-8 -msse4.2 -m64 /GR /EHsc  -stdlib=libc++ -Wno-return-type-c-linkage -Wno-unneeded-internal-declaration -std=c++11 -fno-strict-aliasing /MD /O2 /Oi /Gy /DNDEBUG /Z7  /Yustdafx.h /showIncludes /Fosrc\CMakeFiles\azurestorage.dir\constants.cpp.obj /Fdsrc\CMakeFiles\azurestorage.dir\ -c -- D:\b\azure-storage-cpp\src\v7.5.0-1d01ff61d2.clean\Microsoft.WindowsAzure.Storage\src\constants.cpp
FAILED: src/CMakeFiles/azurestorage.dir/constants.cpp.obj 
D:\installed\x64-windows\compiler-llvm\bin\clang-cl.exe   -TP -DBOOST_CONTAINER_DYN_LINK -DBOOST_CONTAINER_NO_LIB -DBOOST_DATE_TIME_DYN_LINK -DBOOST_DATE_TIME_NO_LIB -DBOOST_LOG_DYN_LINK -DCPPREST_NO_SSL_LEAK_SUPPRESS -DUNICODE -D_TURN_OFF_PLATFORM_STRING -D_UNICODE -D_WIN32 -Dazurestorage_EXPORTS -ID:\b\azure-storage-cpp\src\v7.5.0-1d01ff61d2.clean\Microsoft.WindowsAzure.Storage\includes -imsvcD:\installed\x64-windows\VS\VC\Tools\MSVC\14.42.34433\include -imsvcD:\installed\x64-windows\VS\VC\Tools\MSVC\14.42.34433\ATLMFC\include -imsvcD:\installed\x64-windows\VS\VC\Auxiliary\VS\include -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\ucrt" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\um" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\shared" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\winrt" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\10\include\10.0.26100.0\cppwinrt" -imsvc"D:\installed\x64-windows\WinSDK\Windows Kits\NETFXSDK\4.8.1\include\um" -imsvcD:\installed\x64-windows-static\include /nologo /DWIN32 /D_WINDOWS -Wno-implicit-function-declaration /utf-8 -msse4.2 -m64 /GR /EHsc  -stdlib=libc++ -Wno-return-type-c-linkage -Wno-unneeded-internal-declaration -std=c++11 -fno-strict-aliasing /MD /O2 /Oi /Gy /DNDEBUG /Z7  /Yustdafx.h /showIncludes /Fosrc\CMakeFiles\azurestorage.dir\constants.cpp.obj /Fdsrc\CMakeFiles\azurestorage.dir\ -c -- D:\b\azure-storage-cpp\src\v7.5.0-1d01ff61d2.clean\Microsoft.WindowsAzure.Storage\src\constants.cpp
clang-cl: warning: unknown argument ignored in clang-cl: '-stdlib=libc++' [-Wunknown-argument]
clang-cl: warning: unknown argument ignored in clang-cl: '-std=c++11' [-Wunknown-argument]
In file included from D:\b\azure-storage-cpp\src\v7.5.0-1d01ff61d2.clean\Microsoft.WindowsAzure.Storage\src\constants.cpp:26:
D:\b\azure-storage-cpp\src\v7.5.0-1d01ff61d2.clean\Microsoft.WindowsAzure.Storage\includes\wascore\constants.dat(20,5): error: definition of dllimport data
   20 | DAT(double_not_a_number, _XPLATSTR("NaN"))
      |     ^

azure-storage-cpp/Microsoft.WindowsAzure.Storage/CMakeLists.txt

Line 96 in 00bb370

elseif(CMAKE_CXX_COMPILER_ID MATCHES "Clang")

If logic in the whole block is just incomplete.