for (auto Size : {1, 32, 67}) {
StringMap<CountCtorCopyAndMove> Map(Size);
auto NumBuckets = Map.getNumBuckets();
+
+ // Prepare the elts in a vector. We do this as a pre-step to shield us
+ // against the internals of std::pair which can introduce spurious move/copy
+ std::vector<std::pair<std::string, CountCtorCopyAndMove>> Elts;
+ for (int i = 0; i < Size; ++i)
+ Elts.emplace_back(Twine(i).str(), CountCtorCopyAndMove());
+
CountCtorCopyAndMove::Move = 0;
CountCtorCopyAndMove::Copy = 0;
for (int i = 0; i < Size; ++i)
- Map.insert(std::make_pair(Twine(i).str(), CountCtorCopyAndMove()));
- // This relies on move-construction elision, and cannot be reliably tested.
- // EXPECT_EQ((unsigned)Size * 3, CountCtorCopyAndMove::Move);
- // No copy is expected.
- EXPECT_EQ(0u, CountCtorCopyAndMove::Copy);
+ Map.insert(Elts[i]);
+ // After the inital copy, the map will move the Elts in the Entry.
+ EXPECT_EQ((unsigned)Size, CountCtorCopyAndMove::Move);
+ // We copy once the pair from the Elts vector
+ EXPECT_EQ((unsigned)Size, CountCtorCopyAndMove::Copy);
// Check that the map didn't grow
EXPECT_EQ(Map.getNumBuckets(), NumBuckets);
}