[ADT] Add a pop_back_val method to the SparseSet container.
The next commit will use it.
llvm-svn: 263455
diff --git a/llvm/include/llvm/ADT/SparseSet.h b/llvm/include/llvm/ADT/SparseSet.h
index a45d1c8..5b6494d 100644
--- a/llvm/include/llvm/ADT/SparseSet.h
+++ b/llvm/include/llvm/ADT/SparseSet.h
@@ -263,6 +263,11 @@
return *insert(ValueT(Key)).first;
}
+ ValueT pop_back_val() {
+ // Sparse does not need to be cleared, see find().
+ return Dense.pop_back_val();
+ }
+
/// erase - Erases an existing element identified by a valid iterator.
///
/// This invalidates all iterators, but erase() returns an iterator pointing
diff --git a/llvm/unittests/ADT/SparseSetTest.cpp b/llvm/unittests/ADT/SparseSetTest.cpp
index eb0e0db..4db7a7d 100644
--- a/llvm/unittests/ADT/SparseSetTest.cpp
+++ b/llvm/unittests/ADT/SparseSetTest.cpp
@@ -183,4 +183,24 @@
EXPECT_FALSE(Set.erase(5));
EXPECT_TRUE(Set.erase(6));
}
+
+TEST(SparseSetTest, PopBack) {
+ USet Set;
+ const unsigned UpperBound = 300;
+ Set.setUniverse(UpperBound);
+ for (unsigned i = 0; i < UpperBound; ++i)
+ Set.insert(i);
+
+ // Make sure pop back returns the values in the reverse order we
+ // inserted them.
+ unsigned Expected = UpperBound;
+ while (!Set.empty())
+ ASSERT_TRUE(--Expected == Set.pop_back_val());
+
+ // Insert again the same elements in the sparse set and make sure
+ // each insertion actually inserts the elements. I.e., check
+ // that the underlying data structure are properly cleared.
+ for (unsigned i = 0; i < UpperBound; ++i)
+ ASSERT_TRUE(Set.insert(i).second);
+}
} // namespace