gtest cannot be compiled with VS 2017 update 2

[bernhardmgruber]

Visual Studio 2017 update 2 (15.5) emits deprecation warnings for each use of things in std::tr1. Unfortunately, gtest treats those warnings as errors.

This issue is currently on the way to be fixed:
google/googletest#1111

In the meanwhile, the following workaround for cmake based projects is advised (read the notes at the end of the gtest issue):

if (MSVC)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /D_SILENCE_TR1_NAMESPACE_DEPRECATION_WARNING")
endif()

This supresses the deprecation warnings.