# Using Google Test in Visual C++ 2012
As always with any library in C++, it's not that easy as just download the sources, compile and use it. Here are my experiences with making it work in Visual C++ 2012:
1. Visual Studio solution is already prepared in msvc/gtest.sln. You just need to confirm upgrading to new version and ignore report with warnings.
2. You only need "gtest" project. It compiles a static library. That's the way I decided to use it. Alternatively you could just include all library sources to your project.
3. The library uses tuple from new C++ that requires variadic templates. Visual C++ doesn't support this feature, so to make it compiling without errors, you need to globally define following macros (in project properties > C/C++ > Preprocessor > Preprocessor Definitions, in both Debug and Release configurations, in both library and your client project):
4. If your project uses different way of linking to the standard library than gtest, you will get linker errors like:
1>gtestd.lib(gtest-all.obj) : error LNK2038: mismatch detected for 'RuntimeLibrary': value 'MTd_StaticDebug' doesn't match value 'MDd_DynamicDebug' in MyTestApp.obj
1>msvcprtd.lib(MSVCP110D.dll) : error LNK2005: "public: __thiscall std::_Container_base12::_Container_base12(void)" (??0_Container_base12@std@@QAE@XZ) already defined in gtestd.lib(gtest-all.obj)
1>msvcprtd.lib(MSVCP110D.dll) : error LNK2005: "public: __thiscall std::_Container_base12::~_Container_base12(void)" (??1_Container_base12@std@@QAE@XZ) already defined in gtestd.lib(gtest-all.obj)
That's probable as default setting for new project is to link it dynamically, while gtest project links it statically. It should be same in both gtest and your project. To change it to linking dynamically, enter project properties > C/C++ > Code Generation > Runtime Library and choose Multi-threaded Debug DLL (for Debug) and Multi-threaded DLL (for Release).
After setting it up, usage of the library is very easy. You just need in your project:
1. Add "include" subdirectory to include directories.
2. #include <gtest/gtest.h>
3. Link with "msvc/gtest/Debug/gtestd.lib" (in Debug) and "msvc/gtest/Release/gtest.lib" (in Release).
4. Write your tests, like:
EXPECT_EQ(4, 2 + 2);
EXPECT_EQ(10, 3 + 7);
5. Write main function:
int main(int argc, char** argv)
There is also a GUI application available, called Guitar (Google Unit Test Application Runner) or gtest-gbar, which allows running your testing application and browsing results in a window instead of console.