- "Scalar angle(int) const" should be "const Vector& angles() const"
- then method "coeffs" could be removed.
- avoid one letter names like h, p, r -> use alpha(), beta(), gamma() ;)
- about the "fromRotation" methods:
- replace the ones which are not static by operator= (as in Quaternion)
- the others are actually static methods: use a capital F: FromRotation
- method "invert" should be removed.
- use a macro to define both float and double EulerAnglesXYZ* typedefs
- AddConstIf -> not used
- no needs for NegateIfXor, compilers are extremely good at optimizing away branches based on compile time constants:
if(IsHeadingOpposite-=IsEven) res.alpha() = -res.alpha();
