Move `prepare_insert` out of the line as type erased `PrepareInsertNonSoo`.

This significantly reduces binary size of big binaries and creates a single hot function instead of many cold. That is decreasing cash misses during code execution.

We also avoid size related computations for tables with no deleted slots, when resize is necessary.

PiperOrigin-RevId: 635527119
Change-Id: I763b135f1f6089051e62e348a07b33536af265ab

1 files changed, 28 insertions, 0 deletions

diff --git a/absl/container/internal/compressed_tuple_test.cc b/absl/container/internal/compressed_tuple_test.cc
index 49818fb8..3cd9e18b 100644
--- a/absl/container/internal/compressed_tuple_test.cc
+++ b/absl/container/internal/compressed_tuple_test.cc
@@ -15,8 +15,11 @@
 #include "absl/container/internal/compressed_tuple.h"
 
 #include <memory>
+#include <set>
 #include <string>
+#include <type_traits>
 #include <utility>
+#include <vector>
 
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
@@ -55,6 +58,7 @@ namespace {
 
 using absl::test_internal::CopyableMovableInstance;
 using absl::test_internal::InstanceTracker;
+using ::testing::Each;
 
 TEST(CompressedTupleTest, Sizeof) {
   EXPECT_EQ(sizeof(int), sizeof(CompressedTuple<int>));
@@ -71,6 +75,30 @@ TEST(CompressedTupleTest, Sizeof) {
             sizeof(CompressedTuple<int, Empty<0>, NotEmpty<double>, Empty<1>>));
 }
 
+TEST(CompressedTupleTest, PointerToEmpty) {
+  auto to_void_ptrs = [](const auto&... objs) {
+    return std::vector<const void*>{static_cast<const void*>(&objs)...};
+  };
+  {
+    using Tuple = CompressedTuple<int, Empty<0>>;
+    EXPECT_EQ(sizeof(int), sizeof(Tuple));
+    Tuple t;
+    EXPECT_THAT(to_void_ptrs(t.get<1>()), Each(&t));
+  }
+  {
+    using Tuple = CompressedTuple<int, Empty<0>, Empty<1>>;
+    EXPECT_EQ(sizeof(int), sizeof(Tuple));
+    Tuple t;
+    EXPECT_THAT(to_void_ptrs(t.get<1>(), t.get<2>()), Each(&t));
+  }
+  {
+    using Tuple = CompressedTuple<int, Empty<0>, Empty<1>, Empty<2>>;
+    EXPECT_EQ(sizeof(int), sizeof(Tuple));
+    Tuple t;
+    EXPECT_THAT(to_void_ptrs(t.get<1>(), t.get<2>(), t.get<3>()), Each(&t));
+  }
+}
+
 TEST(CompressedTupleTest, OneMoveOnRValueConstructionTemp) {
   InstanceTracker tracker;
   CompressedTuple<CopyableMovableInstance> x1(CopyableMovableInstance(1));