Примеры ошибок, обнаруженных с помощью диагностики V1043
V1043. A global object variable is declared in the header. Multiple copies of it will be created in all translation units that include this header file.
GZDoom
V1043 A global object variable 'nullAngle' is declared in the header. Multiple copies of it will be created in all translation units that include this header file. vectors.h 1730
constexpr DAngle nullAngle = DAngle::fromDeg(0.);