MSVC_VERSION

The version of Microsoft Visual C/C++ being used if any. If a compiler simulating Visual C++ is being used, this variable is set to the toolset version simulated as given by the _MSC_VER preprocessor definition.

Known version numbers are:

1200      = VS  6.0
1300      = VS  7.0
1310      = VS  7.1
1400      = VS  8.0 (v80 toolset)
1500      = VS  9.0 (v90 toolset)
1600      = VS 10.0 (v100 toolset)
1700      = VS 11.0 (v110 toolset)
1800      = VS 12.0 (v120 toolset)
1900      = VS 14.0 (v140 toolset)
1910-1919 = VS 15.0 (v141 toolset)
1920-1929 = VS 16.0 (v142 toolset)

See also the CMAKE_<LANG>_COMPILER_VERSION and MSVC_TOOLSET_VERSION variable.