[inner.product] (original) (raw)

26 Algorithms library [algorithms]

26.10 Generalized numeric operations [numeric.ops]

26.10.5 Inner product [inner.product]

template<class InputIterator1, class InputIterator2, class T> constexpr T inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, T init);template<class InputIterator1, class InputIterator2, class T,class BinaryOperation1, class BinaryOperation2> constexpr T inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, T init, BinaryOperation1 binary_op1, BinaryOperation2 binary_op2);

In the ranges [first1, last1] and [first2, first2 + (last1 - first1)]binary_op1 and binary_op2neither modifies elements nor invalidates iterators or subranges.207

Effects: Computes its result by initializing the accumulator acc with the initial value initand then modifying it withacc = std​::​move(acc) + (*i1) * (*i2) oracc = binary_op1(std​::​move(acc), binary_op2(*i1, *i2))for every iterator i1 in the range [first1, last1) and iterator i2 in the range [first2, first2 + (last1 - first1)) in order.