in roboschool/cpp-household/glsl/nv_math.inl [1960:1968]
inline void nv_is_valid(const vector3<T>& v)
{
#ifdef WIN32
assert(!_isnan(v.x) && !_isnan(v.y) && !_isnan(v.z) &&
_finite(v.x) && _finite(v.y) && _finite(v.z));
#else
assert(!isnan(v.x) && !isnan(v.y) && !isnan(v.z));
#endif
}