Build the library (as a static library) is fine. However, when using it, all my test files fail with:
1> TestArchive.cpp
1>c:\winsrc\libraries\unittest++\src\RequiredCheckTestReporter.h(26): error C2220: warning treated as error - no 'object' file generated
1>c:\winsrc\libraries\unittest++\src\RequiredCheckTestReporter.h(26): warning C4512: 'UnitTest::RequiredCheckTestReporter' : assignment operator could not be generated
1> c:\winsrc\libraries\unittest++\src\RequiredCheckTestReporter.h(14) : see declaration of 'UnitTest::RequiredCheckTestReporter'

(yes, I have warnings as errors turned on)

The same code builds fine on vs2015.