[llvm] r220168 - [ADT] Add a 'find_as' operation to DenseSet.

[Lang Hames]

Author: lhames
Date: Sun Oct 19 14:36:33 2014
New Revision: 220168

URL: http://llvm.org/viewvc/llvm-project?rev=220168&view=rev
Log:
[ADT] Add a 'find_as' operation to DenseSet.

This operation is analogous to its counterpart in DenseMap: It allows lookup
via cheap-to-construct keys (provided that getHashValue and isEqual are
implemented for the cheap key-type in the DenseMapInfo specialization).

Thanks to Chandler for the review.


Modified:
    llvm/trunk/include/llvm/ADT/DenseSet.h
    llvm/trunk/unittests/ADT/DenseSetTest.cpp

Modified: llvm/trunk/include/llvm/ADT/DenseSet.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/DenseSet.h?rev=220168&r1=220167&r2=220168&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/DenseSet.h (original)
+++ llvm/trunk/include/llvm/ADT/DenseSet.h Sun Oct 19 14:36:33 2014
@@ -110,6 +110,21 @@ public:
   const_iterator end() const { return ConstIterator(TheMap.end()); }
 
   iterator find(const ValueT &V) { return Iterator(TheMap.find(V)); }
+
+  /// Alternative version of find() which allows a different, and possibly less
+  /// expensive, key type.
+  /// The DenseMapInfo is responsible for supplying methods
+  /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key type
+  /// used.
+  template <class LookupKeyT>
+  iterator find_as(const LookupKeyT &Val) {
+    return Iterator(TheMap.find_as(Val));
+  }
+  template <class LookupKeyT>
+  const_iterator find_as(const LookupKeyT &Val) const {
+    return ConstIterator(TheMap.find_as(Val));
+  }
+
   void erase(Iterator I) { return TheMap.erase(I.I); }
   void erase(ConstIterator CI) { return TheMap.erase(CI.I); }
 

Modified: llvm/trunk/unittests/ADT/DenseSetTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/DenseSetTest.cpp?rev=220168&r1=220167&r2=220168&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/DenseSetTest.cpp (original)
+++ llvm/trunk/unittests/ADT/DenseSetTest.cpp Sun Oct 19 14:36:33 2014
@@ -27,4 +27,42 @@ TEST_F(DenseSetTest, DoubleEntrySetTest)
   EXPECT_EQ(0u, set.count(2));
 }
 
+struct TestDenseSetInfo {
+  static inline unsigned getEmptyKey() { return ~0; }
+  static inline unsigned getTombstoneKey() { return ~0U - 1; }
+  static unsigned getHashValue(const unsigned& Val) { return Val * 37U; }
+  static unsigned getHashValue(const char* Val) {
+    return (unsigned)(Val[0] - 'a') * 37U;
+  }
+  static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
+    return LHS == RHS;
+  }
+  static bool isEqual(const char* LHS, const unsigned& RHS) {
+    return (unsigned)(LHS[0] - 'a') == RHS;
+  }
+};
+
+TEST(DenseSetCustomTest, FindAsTest) {
+  DenseSet<unsigned, TestDenseSetInfo> set;
+  set.insert(0);
+  set.insert(1);
+  set.insert(2);
+
+  // Size tests
+  EXPECT_EQ(3u, set.size());
+
+  // Normal lookup tests
+  EXPECT_EQ(1u, set.count(1));
+  EXPECT_EQ(0u, *set.find(0));
+  EXPECT_EQ(1u, *set.find(1));
+  EXPECT_EQ(2u, *set.find(2));
+  EXPECT_TRUE(set.find(3) == set.end());
+
+  // find_as() tests
+  EXPECT_EQ(0u, *set.find_as("a"));
+  EXPECT_EQ(1u, *set.find_as("b"));
+  EXPECT_EQ(2u, *set.find_as("c"));
+  EXPECT_TRUE(set.find_as("d") == set.end());
+}
+
 }