[/
    Copyright 2010 Neil Groves
    Distributed under the Boost Software License, Version 1.0.
    (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
/]
[section:accumulate accumulate]

[heading Prototype]

``
template<
    class SinglePassRange,
    class Value
    >
Value accumulate(const SinglePassRange& source_rng,
                 Value init);

template<
    class SinglePassRange,
    class Value,
    class BinaryOperation
    >
Value accumulate(const SinglePassRange& source_rng,
                 Value init,
                 BinaryOperation op);
``

[heading Description]

`accumulate` is a generalisation of summation. It computes a binary operation (`operator+`
in the non-predicate version) of `init` and all of the elements in `rng`.

The return value is the resultant value of the above algorithm.

[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.
# `Value` is a model of the `AssignableConcept`.
# An `operator+` is defined for a left-hand operand of type `Value` and a right-hand operand of the `SinglePassRange` value type.
# The return type of the above operator is convertible to `Value`.

[heading For the second version]

# `SinglePassRange` is a model of the __single_pass_range__ Concept.
# `Value` is a model of the `AssignableConcept`.
# `BinaryOperation` is a model of the `BinaryFunctionConcept`.
# `Value` is convertible to `BinaryOperation`'s first argument type.
# `SinglePassRange`'s value type is convertible to `BinaryOperation`'s second argument type.
# The return type of `BinaryOperation` is convertible to `Value`.

[heading Complexity]

Linear. Exactly `distance(source_rng)`.

[endsect]