intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 19 insertions, 0 deletions

diff --git a/util/generic/string_transparent_hash_ut.cpp b/util/generic/string_transparent_hash_ut.cpp
new file mode 100644
index 0000000000..b87fa2843e
--- /dev/null
+++ b/util/generic/string_transparent_hash_ut.cpp
@@ -0,0 +1,19 @@
+#include "string.h"
+#include "vector.h"
+#include "strbuf.h"
+
+#include <library/cpp/testing/unittest/registar.h>
+#include <library/cpp/containers/absl_flat_hash/flat_hash_set.h>
+
+#include <util/str_stl.h>
+
+Y_UNIT_TEST_SUITE(StringHashFunctorTests) {
+    Y_UNIT_TEST(TestTransparencyWithUnorderedSet) {
+        // Using Abseil hash set because `std::unordered_set` is transparent only from C++20 (while
+        // we stuck with C++17 right now).
+        absl::flat_hash_set<TString, THash<TString>, TEqualTo<TString>> s = {"foo"};
+        // If either `THash` or `TEqualTo` is not transparent compilation will fail.
+        UNIT_ASSERT_UNEQUAL(s.find(TStringBuf("foo")), s.end());
+        UNIT_ASSERT_EQUAL(s.find(TStringBuf("bar")), s.end());
+    }
+}