namespace alps { template <class T> typename TypeTraits<T>::norm_t abs2(T x); template <class T> T abs2(const std::complex<T>& x); std::size_t binomial(std::size_t l,std::size_t n); }
returns the square of the absolute value. It is optimized by specialization for complex numbers.template <class T> typename TypeTraits<T>::norm_t abs2(T x); template <class T> T abs2(cosnt std::complex<T>& x);
returns the binomial of of l and n.std::size_t binomial(std::size_t l,std::size_t n);