v3/numeric/accumulate.hpp

0001 /// \file
0002 // Range v3 library
0003 //
0004 //  Copyright Eric Niebler 2013-present
0005 //
0006 //  Use, modification and distribution is subject to the
0007 //  Boost Software License, Version 1.0. (See accompanying
0008 //  file LICENSE_1_0.txt or copy at
0009 //  http://www.boost.org/LICENSE_1_0.txt)
0010 //
0011 // Project home: https://github.com/ericniebler/range-v3
0012 //
0013 #ifndef RANGES_V3_NUMERIC_ACCUMULATE_HPP
0014 #define RANGES_V3_NUMERIC_ACCUMULATE_HPP
0015
0016 #include <meta/meta.hpp>
0017
0018 #include <range/v3/functional/arithmetic.hpp>
0019 #include <range/v3/functional/identity.hpp>
0020 #include <range/v3/functional/invoke.hpp>
0021 #include <range/v3/iterator/concepts.hpp>
0022 #include <range/v3/iterator/traits.hpp>
0023 #include <range/v3/range/access.hpp>
0024 #include <range/v3/range/concepts.hpp>
0025 #include <range/v3/range/traits.hpp>
0026 #include <range/v3/utility/static_const.hpp>
0027
0028 #include <range/v3/detail/prologue.hpp>
0029
0030 namespace ranges
0031 {
0032     /// \addtogroup group-numerics
0033     /// @{
0034     struct accumulate_fn
0035     {
0036         template(typename I, typename S, typename T, typename Op = plus,
0037                  typename P = identity)(
0038             requires sentinel_for<S, I> AND input_iterator<I> AND
0039                 indirectly_binary_invocable_<Op, T *, projected<I, P>> AND
0040                 assignable_from<T &, indirect_result_t<Op &, T *, projected<I, P>>>)
0041         T operator()(I first, S last, T init, Op op = Op{},
0042                         P proj = P{}) const
0043         {
0044             for(; first != last; ++first)
0045                 init = invoke(op, init, invoke(proj, *first));
0046             return init;
0047         }
0048
0049         template(typename Rng, typename T, typename Op = plus, typename P = identity)(
0050             requires input_range<Rng> AND
0051                 indirectly_binary_invocable_<Op, T *, projected<iterator_t<Rng>, P>> AND
0052                 assignable_from<
0053                     T &, indirect_result_t<Op &, T *, projected<iterator_t<Rng>, P>>>)
0054         T operator()(Rng && rng, T init, Op op = Op{}, P proj = P{}) const
0055         {
0056             return (*this)(
0057                 begin(rng), end(rng), std::move(init), std::move(op), std::move(proj));
0058         }
0059     };
0060
0061     RANGES_INLINE_VARIABLE(accumulate_fn, accumulate)
0062     /// @}
0063 } // namespace ranges
0064
0065 #include <range/v3/detail/epilogue.hpp>
0066
0067 #endif