Before this PR this code (in the test.cpp) was impossible:

enum class TestEnum : int8_t {  A, B };
TEST_EQ(MyGame::Example::TestEnum::A, Foo());

Due to ambiguity of type deduction, this code caused a compilation error like this:

error C2679: binary '<<': no operator found which takes a right-hand operand of type 'T' (or there is no acceptable conversion) with [ T=MyGame::Example::TestEnum ]
.... (listing of all possible specializations)

This is a well-known problem (C++ DR1601):

• http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1601
• https://stackoverflow.com/questions/34336024/ambiguous-overload-when-writing-an-enum-with-an-enum-base-but-only-with-clang

However, all modern compilers break the rule C++17 16.4.2 introduced by DR 1601:

A conversion that promotes an enumeration whose underlying type is fixed to its underlying type is better than one that promotes to the promoted underlying type, if the two are different.

This PR adds a workaround and allows the use of simple checking of enum class values in tests:

TEST_EQ(MyGame::Example::TestEnum::A, MyGame::Example::TestEnum::B);