Intermediate changes

Author: robot-piglet

util/generic/string_transparent_hash_ut.cpp

@@ -3,15 +3,27 @@
 #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>
 
+#ifdef __cpp_lib_generic_unordered_lookup
+    #include <unordered_set>
+
+template <class T, class THasher, class TPred>
+using THashSetType = std::unordered_set<T, THasher, TPred>;
+#else
+    // Using Abseil hash set because `std::unordered_set` is transparent only from libstdc++11.
+    // Meanwhile clang-linux-x86_64-release-stl-system autocheck sets OS_SDK=ubuntu-20,
+    // that support libstdc++10 by default.
+    #include <library/cpp/containers/absl_flat_hash/flat_hash_set.h>
+
+template <class T, class THasher, class TPred>
+using THashSetType = absl::flat_hash_set<T, THasher, TPred>;
+#endif
+
 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"};
+        THashSetType<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());

util/generic/ut/ya.make

@@ -41,6 +41,7 @@ SRCS(
     generic/stack_ut.cpp
     generic/store_policy_ut.cpp
     generic/strbuf_ut.cpp
+    generic/string_transparent_hash_ut.cpp
     generic/string_ut.cpp
     generic/typelist_ut.cpp
     generic/typetraits_ut.cpp
@@ -56,16 +57,8 @@ SRCS(
 
 INCLUDE(${ARCADIA_ROOT}/util/tests/ya_util_tests.inc)
 
-IF (NOT OS_IOS AND NOT ARCH_PPC64LE)
-    # Abseil fails to build (with linkage error) on ios and with compilation error on PowerPC
-    # (somewhere in unscaledcycleclock.cc).
-    PEERDIR(
-        library/cpp/containers/absl_flat_hash
-    )
-
-    SRCS(
-        generic/string_transparent_hash_ut.cpp
-    )
-ENDIF()
+PEERDIR(
+    library/cpp/containers/absl_flat_hash
+)
 
 END()