[llvm] Add contains(KeyType) -> bool methods to SmallPtrSet

Matches C++20 API addition.

Differential Revision: https://reviews.llvm.org/D83449

(cherry picked from commit a0385bd)

Author: dwblaikie

llvm/include/llvm/ADT/SmallPtrSet.h

@@ -378,6 +378,9 @@ class SmallPtrSetImpl : public SmallPtrSetImplBase {
   iterator find(ConstPtrType Ptr) const {
     return makeIterator(find_imp(ConstPtrTraits::getAsVoidPointer(Ptr)));
   }
+  bool contains(ConstPtrType Ptr) const {
+    return find_imp(ConstPtrTraits::getAsVoidPointer(Ptr)) != EndPointer();
+  }
 
   template <typename IterT>
   void insert(IterT I, IterT E) {

llvm/unittests/ADT/SmallPtrSetTest.cpp

@@ -313,8 +313,8 @@ TEST(SmallPtrSetTest, ConstTest) {
   IntSet.insert(B);
   EXPECT_EQ(IntSet.count(B), 1u);
   EXPECT_EQ(IntSet.count(C), 1u);
-  EXPECT_NE(IntSet.find(B), IntSet.end());
-  EXPECT_NE(IntSet.find(C), IntSet.end());
+  EXPECT_TRUE(IntSet.contains(B));
+  EXPECT_TRUE(IntSet.contains(C));
 }
 
 // Verify that we automatically get the const version of PointerLikeTypeTraits
@@ -327,7 +327,7 @@ TEST(SmallPtrSetTest, ConstNonPtrTest) {
   TestPair Pair(&A[0], 1);
   IntSet.insert(Pair);
   EXPECT_EQ(IntSet.count(Pair), 1u);
-  EXPECT_NE(IntSet.find(Pair), IntSet.end());
+  EXPECT_TRUE(IntSet.contains(Pair));
 }
 
 // Test equality comparison.
@@ -367,3 +367,31 @@ TEST(SmallPtrSetTest, EqualityComparison) {
   EXPECT_NE(c, e);
   EXPECT_NE(e, d);
 }
+
+TEST(SmallPtrSetTest, Contains) {
+  SmallPtrSet<int *, 2> Set;
+  int buf[4] = {0, 11, 22, 11};
+  EXPECT_FALSE(Set.contains(&buf[0]));
+  EXPECT_FALSE(Set.contains(&buf[1]));
+
+  Set.insert(&buf[0]);
+  Set.insert(&buf[1]);
+  EXPECT_TRUE(Set.contains(&buf[0]));
+  EXPECT_TRUE(Set.contains(&buf[1]));
+  EXPECT_FALSE(Set.contains(&buf[3]));
+
+  Set.insert(&buf[1]);
+  EXPECT_TRUE(Set.contains(&buf[0]));
+  EXPECT_TRUE(Set.contains(&buf[1]));
+  EXPECT_FALSE(Set.contains(&buf[3]));
+
+  Set.erase(&buf[1]);
+  EXPECT_TRUE(Set.contains(&buf[0]));
+  EXPECT_FALSE(Set.contains(&buf[1]));
+
+  Set.insert(&buf[1]);
+  Set.insert(&buf[2]);
+  EXPECT_TRUE(Set.contains(&buf[0]));
+  EXPECT_TRUE(Set.contains(&buf[1]));
+  EXPECT_TRUE(Set.contains(&buf[2]));
+}