cpp/algorithm/ranges/fold left first with iter

Left-folds the elements of given range, that is, returns the result of evaluation of the chain expression:, where , , ..., are elements of the range.

Informally, behaves like std's overload that accepts a binary predicate, except that the  is used internally as an initial element.

The behavior is undefined if is not a valid range.

@1@ The range is.

@2@ Same as, except that uses as the range, as if by using  as  and  as.

@4@ The return type alias. See Return value section for details.

Return value
Let be.

@1@ An object of type. If the range is empty, the return value is.
 * The member holds an iterator to the end of the range.
 * The member holds the result of the left-fold of given range over.

@2@ Same as except that the return type is.

Complexity
Exactly (assuming the range is not empty) applications of the function object.