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- /// \file
- // Range v3 library
- //
- // Copyright Eric Niebler 2014-present
- //
- // Use, modification and distribution is subject to 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)
- //
- // Project home: https://github.com/ericniebler/range-v3
- //
- #ifndef RANGES_V3_ALGORITHM_TRANSFORM_HPP
- #define RANGES_V3_ALGORITHM_TRANSFORM_HPP
-
- #include <utility>
-
- #include <meta/meta.hpp>
-
- #include <range/v3/range_fwd.hpp>
-
- #include <range/v3/algorithm/result_types.hpp>
- #include <range/v3/functional/identity.hpp>
- #include <range/v3/functional/invoke.hpp>
- #include <range/v3/iterator/concepts.hpp>
- #include <range/v3/iterator/traits.hpp>
- #include <range/v3/iterator/unreachable_sentinel.hpp>
- #include <range/v3/range/access.hpp>
- #include <range/v3/range/concepts.hpp>
- #include <range/v3/range/dangling.hpp>
- #include <range/v3/range/traits.hpp>
- #include <range/v3/utility/static_const.hpp>
-
- namespace ranges
- {
- /// \addtogroup group-algorithms
- /// @{
- template<typename I, typename O>
- using unary_transform_result = detail::in_out_result<I, O>;
-
- template<typename I1, typename I2, typename O>
- using binary_transform_result = detail::in1_in2_out_result<I1, I2, O>;
-
- RANGES_BEGIN_NIEBLOID(transform)
-
- // Single-range variant
- /// \brief function template \c transform
- template<typename I, typename S, typename O, typename F, typename P = identity>
- auto RANGES_FUN_NIEBLOID(transform)(
- I first, S last, O out, F fun, P proj = P{}) //
- ->CPP_ret(unary_transform_result<I, O>)( //
- requires input_iterator<I> && sentinel_for<S, I> &&
- weakly_incrementable<O> && copy_constructible<F> &&
- writable<O, indirect_result_t<F &, projected<I, P>>>)
- {
- for(; first != last; ++first, ++out)
- *out = invoke(fun, invoke(proj, *first));
- return {first, out};
- }
-
- /// \overload
- template<typename Rng, typename O, typename F, typename P = identity>
- auto RANGES_FUN_NIEBLOID(transform)(Rng && rng, O out, F fun, P proj = P{}) //
- ->CPP_ret(unary_transform_result<safe_iterator_t<Rng>, O>)( //
- requires input_range<Rng> && weakly_incrementable<O> &&
- copy_constructible<F> &&
- writable<O, indirect_result_t<F &, projected<iterator_t<Rng>, P>>>)
- {
- return (*this)(
- begin(rng), end(rng), std::move(out), std::move(fun), std::move(proj));
- }
-
- // Double-range variant, 4-iterator version
- /// \overload
- template<typename I0,
- typename S0,
- typename I1,
- typename S1,
- typename O,
- typename F,
- typename P0 = identity,
- typename P1 = identity>
- auto RANGES_FUN_NIEBLOID(transform)(I0 begin0,
- S0 end0,
- I1 begin1,
- S1 end1,
- O out,
- F fun,
- P0 proj0 = P0{},
- P1 proj1 = P1{}) //
- ->CPP_ret(binary_transform_result<I0, I1, O>)( //
- requires input_iterator<I0> && sentinel_for<S0, I0> &&
- input_iterator<I1> && sentinel_for<S1, I1> && weakly_incrementable<O> &&
- copy_constructible<F> &&
- writable<O, indirect_result_t<F &, projected<I0, P0>, projected<I1, P1>>>)
- {
- for(; begin0 != end0 && begin1 != end1; ++begin0, ++begin1, ++out)
- *out = invoke(fun, invoke(proj0, *begin0), invoke(proj1, *begin1));
- return {begin0, begin1, out};
- }
-
- /// \overload
- template<typename Rng0,
- typename Rng1,
- typename O,
- typename F,
- typename P0 = identity,
- typename P1 = identity>
- auto RANGES_FUN_NIEBLOID(transform)(
- Rng0 && rng0, Rng1 && rng1, O out, F fun, P0 proj0 = P0{}, P1 proj1 = P1{}) //
- ->CPP_ret(binary_transform_result<safe_iterator_t<Rng0>,
- safe_iterator_t<Rng1>,
- O>)( //
- requires input_range<Rng0> && input_range<Rng1> &&
- weakly_incrementable<O> && copy_constructible<F> &&
- writable<O,
- indirect_result_t<F &,
- projected<iterator_t<Rng0>, P0>,
- projected<iterator_t<Rng1>, P1>>>)
- {
- return (*this)(begin(rng0),
- end(rng0),
- begin(rng1),
- end(rng1),
- std::move(out),
- std::move(fun),
- std::move(proj0),
- std::move(proj1));
- }
-
- // Double-range variant, 3-iterator version
- /// \overload
- template<typename I0,
- typename S0,
- typename I1,
- typename O,
- typename F,
- typename P0 = identity,
- typename P1 = identity>
- RANGES_DEPRECATED(
- "Use the variant of ranges::transform that takes an upper bound "
- "for both input ranges")
- auto RANGES_FUN_NIEBLOID(transform)(I0 begin0,
- S0 end0,
- I1 begin1,
- O out,
- F fun,
- P0 proj0 = P0{},
- P1 proj1 = P1{}) //
- ->CPP_ret(binary_transform_result<I0, I1, O>)( //
- requires input_iterator<I0> && sentinel_for<S0, I0> &&
- input_iterator<I1> && weakly_incrementable<O> && copy_constructible<F> &&
- writable<O, indirect_result_t<F &, projected<I0, P0>, projected<I1, P1>>>)
- {
- return (*this)(std::move(begin0),
- std::move(end0),
- std::move(begin1),
- unreachable,
- std::move(out),
- std::move(fun),
- std::move(proj0),
- std::move(proj1));
- }
-
- /// \overload
- template<typename Rng0,
- typename I1Ref,
- typename O,
- typename F,
- typename P0 = identity,
- typename P1 = identity>
- RANGES_DEPRECATED(
- "Use the variant of ranges::transform that takes an upper bound "
- "for both input ranges")
- auto RANGES_FUN_NIEBLOID(transform)(Rng0 && rng0,
- I1Ref && begin1,
- O out,
- F fun,
- P0 proj0 = P0{},
- P1 proj1 = P1{}) //
- ->CPP_ret(
- binary_transform_result<safe_iterator_t<Rng0>, uncvref_t<I1Ref>, O>)( //
- requires input_range<Rng0> && input_iterator<uncvref_t<I1Ref>> &&
- weakly_incrementable<O> && copy_constructible<F> &&
- writable<O,
- indirect_result_t<F &,
- projected<iterator_t<Rng0>, P0>,
- projected<uncvref_t<I1Ref>, P1>>>)
- {
- return (*this)(begin(rng0),
- end(rng0),
- static_cast<I1Ref &&>(begin1),
- unreachable,
- std::move(out),
- std::move(fun),
- std::move(proj0),
- std::move(proj1));
- }
-
- RANGES_END_NIEBLOID(transform)
-
- namespace cpp20
- {
- using ranges::binary_transform_result;
- using ranges::transform;
- using ranges::unary_transform_result;
- } // namespace cpp20
- /// @}
- } // namespace ranges
-
- #endif // include guard
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