template<typename T>
class SGQuat;
template<typename T>
+class SGVec2;
+template<typename T>
class SGVec3;
template<typename T>
class SGVec4;
typedef SGMisc<double> SGMiscd;
typedef SGQuat<float> SGQuatf;
typedef SGQuat<double> SGQuatd;
+typedef SGVec2<float> SGVec2f;
+typedef SGVec2<double> SGVec2d;
typedef SGVec3<float> SGVec3f;
typedef SGVec3<double> SGVec3d;
typedef SGVec4<float> SGVec4f;