[section:partial_sum partial_sum]

[heading Prototype]

``
template<class SinglePassRange,
         class OutputIterator>
OutputIterator partial_sum(const SinglePassRange& rng,
                           OutputIterator out_it);

template<class SinglePassRange,
         class OutputIterator,
         class BinaryOperation>
OutputIterator partial_sum(const SinglePassRange& rng,
                           OutputIterator out_it,
                           BinaryOperation op);
``

[heading Description]

`partial_sum` calculates a generalised partial sum of `rng` in the same manner as
`std::partial_sum(boost::begin(rng), boost::end(rng), out_it)`. See __sgi_partial_sum__.


[heading Definition]

Defined in the header file `boost/range/numeric.hpp`

[heading Requirements]

[heading For the first version]

# `SinglePassRange` is a model of the __single_pass_range__ Concept.
# `OutputIterator` is a model of the `OutputIteratorConcept`.
# If `x` and `y` are objects of `SinglePassRange`'s value type, then `x + y` is defined.
# The return type of `x + y` is convertible to the value type of `SinglePassRange`.
# The value type of `SinglePassRange` is convertible to a type in `OutputIterator`'s set of value types.

[heading For the second version]

# `SinglePassRange` is a model of the __single_pass_range__ Concept.
# `OutputIterator` is a model of the `OutputIteratorConcept`.
# `BinaryOperation` is a model of the `BinaryFunctionConcept`.
# The result type of `BinaryOperation` is convertible to the value type of `SinglePassRange`.
# The value type of `SinglePassRange` is convertible to a type in `OutputIterator`'s set of value types.

[heading Precondition:]

`[result, result + distance(rng))` is a valid range.

[heading Complexity]

Linear. If `empty(rng)` then zero applications, otherwise `distance(rng) - 1` applications are performed.

[endsect]