CMake generation with Visual Studio 2019 and Intel Compiler 2019 u4 broken

[AndrewC]

Referring to the problem in this thread regarding the use of "Default"

https://software.intel.com/en-us/forums/intel-c-compiler/topic/811512

This issue breaks CMake generation for CMake 3.15.1 Visual Studio 2019 using the Intel Compiler 2019 u4 toolset

The error shows in CMake as

$ cmake ../ -G"Visual Studio 16 2019" -T"Intel C++ Compiler 19.0"
-- Selecting Windows SDK version 10.0.17763.0 to target Windows 10.0.18362.
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
CMake Error at CMakeLists.txt:3 (project):
  No CMAKE_C_COMPILER could be found.

Works fine for Visual Studio 2017

$ cmake ../ -G"Visual Studio 15 2017" -T"Intel C++ Compiler 19.0"
-- Selecting Windows SDK version 10.0.17763.0 to target Windows 10.0.18362.
-- The C compiler identification is Intel 19.0.4.20190417
-- The CXX compiler identification is Intel 19.0.4.20190417

Digging deeper shows the cause of the error

 C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Microsoft\VC\v160\Platforms\x64\PlatformToolsets\Intel C++ Compiler 19.0\Toolset.targets(350,5): error : Element <LanguageStandard> has an invalid value of "Default".

 C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Microsoft\VC\v160\Platforms\x64\PlatformToolsets\Intel C++ Compiler 19.0\Toolset.targets(350,5): error MSB6011: Invalid parameters passed to the Intel.Build.ICLTasks.ICL task.

[AndrewC]

There is a workaround for this issue

Edit the file C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Microsoft\VC\v160\Microsoft.Cl.Common.props

Find the LanguageStandard tag and change the value from "Default" to something like "stdcpp17"