[libc++][ranges] Implement ranges::transform
Reviewed By: ldionne, var-const, #libc
Spies: libcxx-commits, mgorny
Differential Revision: https://reviews.llvm.org/D122173
NOKEYCHECK=True
GitOrigin-RevId: 3ba8548c8e04bb301c4243887362c54bfbd4af8b
diff --git a/include/CMakeLists.txt b/include/CMakeLists.txt
index 7cf305a..30edc3f 100644
--- a/include/CMakeLists.txt
+++ b/include/CMakeLists.txt
@@ -75,6 +75,7 @@
__algorithm/ranges_min_element.h
__algorithm/ranges_mismatch.h
__algorithm/ranges_swap_ranges.h
+ __algorithm/ranges_transform.h
__algorithm/remove.h
__algorithm/remove_copy.h
__algorithm/remove_copy_if.h
diff --git a/include/__algorithm/ranges_transform.h b/include/__algorithm/ranges_transform.h
new file mode 100644
index 0000000..3c13b1b
--- /dev/null
+++ b/include/__algorithm/ranges_transform.h
@@ -0,0 +1,170 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_RANGES_TRANSFORM_H
+#define _LIBCPP___ALGORITHM_RANGES_TRANSFORM_H
+
+#include <__algorithm/in_in_out_result.h>
+#include <__algorithm/in_out_result.h>
+#include <__concepts/constructible.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__iterator/concepts.h>
+#include <__iterator/projected.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+
+template <class _Ip, class _Op>
+using unary_transform_result = in_out_result<_Ip, _Op>;
+
+template <class _I1, class _I2, class _O1>
+using binary_transform_result = in_in_out_result<_I1, _I2, _O1>;
+
+namespace __transform {
+struct __fn {
+private:
+ template <class _InIter, class _Sent,
+ class _OutIter,
+ class _Func,
+ class _Proj>
+ _LIBCPP_HIDE_FROM_ABI static constexpr
+ unary_transform_result<_InIter, _OutIter> __unary(_InIter __first, _Sent __last,
+ _OutIter __result,
+ _Func& __operation,
+ _Proj& __projection) {
+ while (__first != __last) {
+ *__result = std::invoke(__operation, std::invoke(__projection, *__first));
+ ++__first;
+ ++__result;
+ }
+
+ return {std::move(__first), std::move(__result)};
+ }
+
+ template <class _InIter1, class _Sent1,
+ class _InIter2, class _Sent2,
+ class _OutIter,
+ class _Func,
+ class _Proj1,
+ class _Proj2>
+ _LIBCPP_HIDE_FROM_ABI static constexpr binary_transform_result<_InIter1, _InIter2, _OutIter>
+ __binary(_InIter1 __first1, _Sent1 __last1,
+ _InIter2 __first2, _Sent2 __last2,
+ _OutIter __result,
+ _Func& __binary_operation,
+ _Proj1& __projection1,
+ _Proj2& __projection2) {
+ while (__first1 != __last1 && __first2 != __last2) {
+ *__result = std::invoke(__binary_operation, std::invoke(__projection1, *__first1),
+ std::invoke(__projection2, *__first2));
+ ++__first1;
+ ++__first2;
+ ++__result;
+ }
+ return {std::move(__first1), std::move(__first2), std::move(__result)};
+ }
+public:
+ template <input_iterator _InIter, sentinel_for<_InIter> _Sent,
+ weakly_incrementable _OutIter,
+ copy_constructible _Func,
+ class _Proj = identity>
+ requires indirectly_writable<_OutIter, indirect_result_t<_Func&, projected<_InIter, _Proj>>>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ unary_transform_result<_InIter, _OutIter> operator()(_InIter __first, _Sent __last,
+ _OutIter __result,
+ _Func __operation,
+ _Proj __proj = {}) const {
+ return __unary(std::move(__first), std::move(__last), std::move(__result), __operation, __proj);
+ }
+
+ template <input_range _Range,
+ weakly_incrementable _OutIter,
+ copy_constructible _Func,
+ class _Proj = identity>
+ requires indirectly_writable<_OutIter, indirect_result_t<_Func, projected<iterator_t<_Range>, _Proj>>>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ unary_transform_result<borrowed_iterator_t<_Range>, _OutIter> operator()(_Range&& __range,
+ _OutIter __result,
+ _Func __operation,
+ _Proj __projection = {}) const {
+ return __unary(ranges::begin(__range), ranges::end(__range), std::move(__result), __operation, __projection);
+ }
+
+ template <input_iterator _InIter1, sentinel_for<_InIter1> _Sent1,
+ input_iterator _InIter2, sentinel_for<_InIter2> _Sent2,
+ weakly_incrementable _OutIter,
+ copy_constructible _Func,
+ class _Proj1 = identity,
+ class _Proj2 = identity>
+ requires indirectly_writable<_OutIter, indirect_result_t<_Func&, projected<_InIter1, _Proj1>,
+ projected<_InIter2, _Proj2>>>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ binary_transform_result<_InIter1, _InIter2, _OutIter> operator()(_InIter1 __first1, _Sent1 __last1,
+ _InIter2 __first2, _Sent2 __last2,
+ _OutIter __result,
+ _Func __binary_operation,
+ _Proj1 __projection1 = {},
+ _Proj2 __projection2 = {}) const {
+ return __binary(std::move(__first1), std::move(__last1),
+ std::move(__first2), std::move(__last2),
+ std::move(__result),
+ __binary_operation,
+ __projection1,
+ __projection2);
+ }
+
+ template <input_range _Range1,
+ input_range _Range2,
+ weakly_incrementable _OutIter,
+ copy_constructible _Func,
+ class _Proj1 = identity,
+ class _Proj2 = identity>
+ requires indirectly_writable<_OutIter, indirect_result_t<_Func&, projected<iterator_t<_Range1>, _Proj1>,
+ projected<iterator_t<_Range2>, _Proj2>>>
+ _LIBCPP_HIDE_FROM_ABI constexpr
+ binary_transform_result<borrowed_iterator_t<_Range1>, borrowed_iterator_t<_Range2>, _OutIter>
+ operator()(_Range1&& __range1,
+ _Range2&& __range2,
+ _OutIter __result,
+ _Func __binary_operation,
+ _Proj1 __projection1 = {},
+ _Proj2 __projection2 = {}) const {
+ return __binary(ranges::begin(__range1), ranges::end(__range1),
+ ranges::begin(__range2), ranges::end(__range2),
+ std::move(__result),
+ __binary_operation,
+ __projection1,
+ __projection2);
+ }
+
+};
+} // namespace __transform
+
+inline namespace __cpo {
+ inline constexpr auto transform = __transform::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_TRANSFORM_H
diff --git a/include/algorithm b/include/algorithm
index a7912cc..d86cfe7 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -110,6 +110,41 @@
requires indirectly_copyable_storable<iterator_t<R>, range_value_t<R>*>
constexpr range_value_t<R>
max(R&& r, Comp comp = {}, Proj proj = {}); // since C++20
+
+ template<class I, class O>
+ using unary_transform_result = in_out_result<I, O>; // since C++20
+
+ template<class I1, class I2, class O>
+ using binary_transform_result = in_in_out_result<I1, I2, O>; // since C++20
+
+ template<input_iterator I, sentinel_for<I> S, weakly_incrementable O,
+ copy_constructible F, class Proj = identity>
+ requires indirectly_writable<O, indirect_result_t<F&, projected<I, Proj>>>
+ constexpr ranges::unary_transform_result<I, O>
+ transform(I first1, S last1, O result, F op, Proj proj = {}); // since C++20
+
+ template<input_range R, weakly_incrementable O, copy_constructible F,
+ class Proj = identity>
+ requires indirectly_writable<O, indirect_result_t<F&, projected<iterator_t<R>, Proj>>>
+ constexpr ranges::unary_transform_result<borrowed_iterator_t<R>, O>
+ transform(R&& r, O result, F op, Proj proj = {}); // since C++20
+
+ template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
+ weakly_incrementable O, copy_constructible F, class Proj1 = identity,
+ class Proj2 = identity>
+ requires indirectly_writable<O, indirect_result_t<F&, projected<I1, Proj1>,
+ projected<I2, Proj2>>>
+ constexpr ranges::binary_transform_result<I1, I2, O>
+ transform(I1 first1, S1 last1, I2 first2, S2 last2, O result,
+ F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
+
+ template<input_range R1, input_range R2, weakly_incrementable O,
+ copy_constructible F, class Proj1 = identity, class Proj2 = identity>
+ requires indirectly_writable<O, indirect_result_t<F&, projected<iterator_t<R1>, Proj1>,
+ projected<iterator_t<R2>, Proj2>>>
+ constexpr ranges::binary_transform_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
+ transform(R1&& r1, R2&& r2, O result,
+ F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
}
constexpr bool // constexpr in C++20
@@ -836,6 +871,7 @@
#include <__algorithm/ranges_min_element.h>
#include <__algorithm/ranges_mismatch.h>
#include <__algorithm/ranges_swap_ranges.h>
+#include <__algorithm/ranges_transform.h>
#include <__algorithm/remove.h>
#include <__algorithm/remove_copy.h>
#include <__algorithm/remove_copy_if.h>
diff --git a/include/module.modulemap b/include/module.modulemap
index 10e944a..aaedf4d 100644
--- a/include/module.modulemap
+++ b/include/module.modulemap
@@ -303,6 +303,7 @@
module ranges_min_element { private header "__algorithm/ranges_min_element.h" }
module ranges_mismatch { private header "__algorithm/ranges_mismatch.h" }
module ranges_swap_ranges { private header "__algorithm/ranges_swap_ranges.h" }
+ module ranges_transform { private header "__algorithm/ranges_transform.h" }
module remove { private header "__algorithm/remove.h" }
module remove_copy { private header "__algorithm/remove_copy.h" }
module remove_copy_if { private header "__algorithm/remove_copy_if.h" }