[flang-commits] [flang] [libc++] Implement ranges::contains (PR #65148)
Konstantin Varlamov via flang-commits
flang-commits at lists.llvm.org
Mon Oct 2 14:34:07 PDT 2023
================
@@ -0,0 +1,252 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// <algorithm>
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity>
+// requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
+// constexpr bool ranges::contains(I first, S last, const T& value, Proj proj = {}); // since C++23
+
+// template<input_range R, class T, class Proj = identity>
+// requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
+// constexpr bool ranges::contains(R&& r, const T& value, Proj proj = {}); // since C++23
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <ranges>
+#include <vector>
+
+#include "almost_satisfies_types.h"
+#include "boolean_testable.h"
+#include "test_iterators.h"
+
+struct NotEqualityComparable {};
+
+template <class Iter, class Sent = Iter>
+concept HasContainsIt = requires(Iter iter, Sent sent) { std::ranges::contains(iter, sent, *iter); };
+
+static_assert(HasContainsIt<int*>);
+static_assert(!HasContainsIt<NotEqualityComparable*>);
+static_assert(!HasContainsIt<InputIteratorNotDerivedFrom>);
+static_assert(!HasContainsIt<InputIteratorNotIndirectlyReadable>);
+static_assert(!HasContainsIt<InputIteratorNotInputOrOutputIterator>);
+static_assert(!HasContainsIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>);
+static_assert(!HasContainsIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>);
+static_assert(!HasContainsIt<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>);
+
+static_assert(!HasContainsIt<int*, int>);
+static_assert(!HasContainsIt<int, int*>);
+static_assert(HasContainsIt<int*, int*>);
+
+template <class Range, class ValT>
+concept HasContainsR = requires(Range&& range) { std::ranges::contains(std::forward<Range>(range), ValT{}); };
+
+static_assert(!HasContainsR<int, int>);
+static_assert(HasContainsR<int[1], int>);
+static_assert(!HasContainsR<NotEqualityComparable[1], NotEqualityComparable>);
+static_assert(!HasContainsR<InputRangeNotDerivedFrom, int>);
+static_assert(!HasContainsR<InputRangeNotIndirectlyReadable, int>);
+static_assert(!HasContainsR<InputRangeNotInputOrOutputIterator, int>);
+static_assert(!HasContainsR<InputRangeNotSentinelSemiregular, int>);
+static_assert(!HasContainsR<InputRangeNotSentinelEqualityComparableWith, int>);
+
+static std::vector<int> comparable_data;
+
+template <class Iter, class Sent = Iter>
+constexpr void test_iterators() {
+ using ValueT = std::iter_value_t<Iter>;
+ { // simple tests
+ ValueT a[] = {1, 2, 3, 4, 5, 6};
+ auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a + 6)));
+ {
+ [[maybe_unused]] std::same_as<bool> decltype(auto) ret =
+ std::ranges::contains(whole.begin(), whole.end(), 3);
+ assert(ret);
+ }
+ {
+ [[maybe_unused]] std::same_as<bool> decltype(auto) ret =
+ std::ranges::contains(whole, 3);
+ assert(ret);
+ }
+ }
+
+ { // check that a range with a single element works
+ ValueT a[] = {32};
+ auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a + 1)));
+ {
+ bool ret = std::ranges::contains(whole.begin(), whole.end(), 32);
+ assert(ret);
+ }
+ {
+ bool ret = std::ranges::contains(whole, 32);
+ assert(ret);
+ }
+ }
+
+ { // check that an empty range works
+ ValueT a[] = {};
+ auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a)));
+ {
+ bool ret = std::ranges::contains(whole.begin(), whole.end(), 1);
+ assert(!ret);
+ }
+ {
+ bool ret = std::ranges::contains(whole, 1);
+ assert(!ret);
+ }
+ }
+
+ { // check that the first element matches
+ ValueT a[] = {32, 3, 2, 1, 0, 23, 21, 9, 40, 100};
+ auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a + 10)));
+ {
+ bool ret = std::ranges::contains(whole.begin(), whole.end(), 32);
+ assert(ret);
+ }
+ {
+ bool ret = std::ranges::contains(whole, 32);
+ assert(ret);
+ }
+ }
+
+ { // check that the last element matches
+ ValueT a[] = {3, 22, 1, 43, 99, 0, 56, 100, 32};
+ auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a + 9)));
+ {
+ bool ret = std::ranges::contains(whole.begin(), whole.end(), 32);
+ assert(ret);
+ }
+ {
+ bool ret = std::ranges::contains(whole, 32);
+ assert(ret);
+ }
+ }
+
+ { // no match
+ ValueT a[] = {13, 1, 21, 4, 5};
+ auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a + 5)));
+ {
+ bool ret = std::ranges::contains(whole.begin(), whole.end(), 10);
+ assert(!ret);
+ }
+ {
+ bool ret = std::ranges::contains(whole, 10);
+ assert(!ret);
+ }
+ }
+
+ { // check that the projections are used
+ int a[] = {1, 9, 0, 13, 25};
+ {
+ bool ret = std::ranges::contains(a, a + 5, -13, [&](int i) { return i * -1; });
+ assert(ret);
+ }
+ {
+ auto range = std::ranges::subrange(a, a + 5);
+ bool ret = std::ranges::contains(range, -13, [&](int i) { return i * -1; });
+ assert(ret);
+ }
+ }
+
+ { // check the nodiscard extension
+ // use #pragma around to suppress error: ignoring return value of function
+ // declared with 'nodiscard' attribute [-Werror,-Wunused-result]
+ #pragma clang diagnostic push
+ #pragma clang diagnostic ignored "-Wunused-result"
+ ValueT a[] = {1, 9, 0, 13, 25};
+ auto whole = std::ranges::subrange(Iter(a), Sent(Iter(a + 5)));
+ std::ranges::contains(whole, 12);
+ #pragma clang diagnostic pop
+ }
+
+ if (!std::is_constant_evaluated())
+ comparable_data.clear();
+}
+
+template <class ElementT>
+class TriviallyComparable {
+ ElementT el_;
+
+public:
+ constexpr TriviallyComparable(ElementT el) : el_(el) {}
+ bool operator==(const TriviallyComparable&) const = default;
+};
+
+template <class IndexT>
+class Comparable {
+ IndexT index_;
+
+public:
+ Comparable(IndexT i)
+ : index_([&]() {
+ IndexT size = static_cast<IndexT>(comparable_data.size());
+ comparable_data.push_back(i);
+ return size;
+ }()) {}
+
+ bool operator==(const Comparable& other) const {
+ return comparable_data[other.index_] == comparable_data[index_];
+ }
+
+ friend bool operator==(const Comparable& lhs, long long rhs) { return comparable_data[lhs.index_] == rhs; }
+};
+
+constexpr bool test() {
+ types::for_each(types::type_list<char, short, int, long, long long,
+ TriviallyComparable<char>, TriviallyComparable<wchar_t>>{},
+ []<class T> {
+ types::for_each(types::cpp20_input_iterator_list<T*>{},
+ []<class Iter> {
+ if constexpr (std::forward_iterator<Iter>)
+ test_iterators<Iter>();
+ test_iterators<Iter, sentinel_wrapper<Iter>>();
+ test_iterators<Iter, sized_sentinel<Iter>>();
+ });
+ });
+
+ {
+ int a[] = {1, 9, 0, 13, 25};
+ int projection_count = 0;
+ // count invocations of the projection
+ {
+ bool ret = std::ranges::contains(a, a + 5, 0,
+ [&](int i) { ++projection_count; return i; });
+ assert(ret);
+ assert(projection_count == 3);
+ }
+ {
+ projection_count = 0;
+ auto range = std::ranges::subrange(a, a + 5);
+ bool ret = std::ranges::contains(range, 0, [&](int i) { ++projection_count; return i; });
+ assert(ret);
+ assert(projection_count == 3);
+ }
+ }
+ return true;
+}
+
+int main(int, char**) {
+ test();
+ static_assert(test());
+
+ types::for_each(types::type_list<Comparable<char>, Comparable<wchar_t>>{},
+ []<class T> {
+ types::for_each(types::cpp20_input_iterator_list<T*>{},
----------------
var-const wrote:
Ultranit: trailing whitespace.
https://github.com/llvm/llvm-project/pull/65148
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