Address AlexG's other potential occurrences

microsoft · Oct 26, 2021 · f847e92 · f847e92
1 parent 76cad46
commit f847e92
Show file tree

Hide file tree

Showing 5 changed files with 83 additions and 16 deletions.
diff --git a/stl/inc/ranges b/stl/inc/ranges
@@ -3777,7 +3777,13 @@ namespace ranges {
                     return *this;
                 }
 
+#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-1559808
                 auto [_Begin, _End] = _RANGES search(subrange{_Current, _Last}, _Parent->_Pattern);
+#else // ^^^ no workaround / workaround vvv
+                auto _Match = _RANGES search(subrange{_Current, _Last}, _Parent->_Pattern);
+                auto _Begin = _Match.begin();
+                auto _End = _Match.end();
+#endif // TRANSITION, DevCom-1559808
                 if (_Begin != _Last && _RANGES empty(_Parent->_Pattern)) {
                     ++_Begin;
                     ++_End;
@@ -3823,7 +3829,13 @@ namespace ranges {
 
         constexpr subrange<iterator_t<_Vw>> _Find_next(iterator_t<_Vw> _It) {
             const auto _Last    = _RANGES end(_Range);
+#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-1559808
             auto [_Begin, _End] = _RANGES search(subrange{_It, _Last}, _Pattern);
+#else // ^^^ no workaround / workaround vvv
+            auto _Match = _RANGES search(subrange{_It, _Last}, _Pattern);
+            auto _Begin = _Match.begin();
+            auto _End = _Match.end();
+#endif // TRANSITION, DevCom-1559808
             if (_Begin != _Last && _RANGES empty(_Pattern)) {
                 ++_Begin;
                 ++_End;

diff --git a/tests/std/tests/P0896R4_ranges_alg_find_end/test.cpp b/tests/std/tests/P0896R4_ranges_alg_find_end/test.cpp
@@ -8,6 +8,7 @@
 #include <ranges>
 #include <span>
 #include <utility>
+#include <vector>
 
 #include <range_algorithm_support.hpp>
 
@@ -71,9 +72,29 @@ constexpr void smoke_test() {
     }
 }
 
+constexpr void test_1559808() {
+    // Regression test for DevCom-1559808, an interaction between vector and the
+    // use of structured bindings in the constexpr evaluator.
+
+    std::vector<int> haystack(33, 42), needle(8, 42); // No particular significance to any numbers in this function
+    using size_type = std::vector<int>::size_type;
+
+    auto result = ranges::find_end(haystack, needle);
+    assert(static_cast<size_type>(result.begin() - haystack.begin()) == haystack.size() - needle.size());
+    assert(result.end() == haystack.end());
+
+    needle.assign(6, 1729);
+    result = ranges::find_end(haystack, needle);
+    assert(result.begin() == haystack.end());
+    assert(result.end() == haystack.end());
+}
+
 int main() {
     STATIC_ASSERT((smoke_test(), true));
     smoke_test();
+
+    STATIC_ASSERT((test_1559808(), true));
+    test_1559808();
 }
 
 #ifndef _PREFAST_ // TRANSITION, GH-1030

diff --git a/tests/std/tests/P0896R4_ranges_alg_search/test.cpp b/tests/std/tests/P0896R4_ranges_alg_search/test.cpp
@@ -8,6 +8,7 @@
 #include <ranges>
 #include <span>
 #include <utility>
+#include <vector>
 
 #include <range_algorithm_support.hpp>
 
@@ -168,8 +169,27 @@ constexpr bool run_tests() {
     return true;
 }
 
+constexpr void test_1559808() {
+    // Regression test for DevCom-1559808, an interaction between vector and the
+    // use of structured bindings in the constexpr evaluator.
+
+    std::vector<int> haystack(33, 42), needle(8, 42); // No particular significance to any numbers in this function
+
+    auto result = ranges::search(haystack, needle);
+    assert(result.begin() == haystack.begin());
+    assert(result.end() == haystack.begin() + ranges::ssize(needle));
+
+    needle.assign(6, 1729);
+    result = ranges::search(haystack, needle);
+    assert(result.begin() == haystack.end());
+    assert(result.end() == haystack.end());
+}
+
 int main() {
     STATIC_ASSERT(run_tests());
     run_tests();
+
+    STATIC_ASSERT((test_1559808(), true));
+    test_1559808();
 }
 #endif // TEST_EVERYTHING
diff --git a/tests/std/tests/P0896R4_ranges_alg_sort/test.cpp b/tests/std/tests/P0896R4_ranges_alg_sort/test.cpp
@@ -54,23 +54,11 @@ struct instantiator {
 
 constexpr void test_1559808() {
     // Regression test for DevCom-1559808, a bad interaction between constexpr vector and the use of structured bindings
-    // in the implemenation of ranges::sort.
+    // in the implementation of ranges::sort.
 
-    auto collatz = [](int n) {
-        vector<int> vec = {n};
-        while (n != 1) {
-            if (n % 2 == 0) {
-                n /= 2;
-            } else {
-                n = n * 3 + 1;
-            }
-            vec.push_back(n);
-        }
-        ranges::sort(vec);
-        return vec.back();
-    };
-
-    assert(collatz(27) == 9232);
+    vector<int> vec(33, 42); // NB: 33 > std::_ISORT_MAX
+    ranges::sort(vec);
+    assert(vec.back() == 42);
 }
 
 int main() {

diff --git a/tests/std/tests/P0896R4_views_split/test.cpp b/tests/std/tests/P0896R4_views_split/test.cpp
@@ -10,6 +10,7 @@
 #include <system_error>
 #include <type_traits>
 #include <utility>
+#include <vector>
 
 #include <range_algorithm_support.hpp>
 using namespace std;
@@ -320,7 +321,32 @@ constexpr bool instantiation_test() {
     return true;
 }
 
+constexpr bool test_1559808() {
+    // Regression test for DevCom-1559808, an interaction between vector and the
+    // use of structured bindings in the constexpr evaluator.
+
+    vector<char> letters{'T', 'h', 'i', 's', ' ', 'i', 's', ' ', 'a', ' ', 't', 'e', 's', 't'};
+    auto r = views::split(letters, ' ');
+    auto i = r.begin();
+    assert(*(*i).begin() == 'T');
+    ++i;
+    assert(*(*i).begin() == 'i');
+    ++i;
+    assert(*(*i).begin() == 'a');
+    ++i;
+    assert(*(*i).begin() == 't');
+    ++i;
+    assert(i == r.end());
+
+    return true;
+}
+
 int main() {
     STATIC_ASSERT(instantiation_test());
     instantiation_test();
+
+#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevDiv-1516290
+    STATIC_ASSERT(test_1559808());
+#endif // TRANSITION, DevDiv-1516290
+    test_1559808();
 }