Add an insert() method to MapVector. Adds the first MapVector unit test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173505 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/MapVector.h

@@ -19,6 +19,7 @@
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/STLExtras.h"
 #include <vector>
 
 namespace llvm {
@@ -84,6 +85,18 @@ public:
     return Pos == Map.end()? ValueT() : Vector[Pos->second].second;
   }
 
+  std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) {
+    std::pair<KeyT, unsigned> Pair = std::make_pair(KV.first, 0);
+    std::pair<typename MapType::iterator, bool> Result = Map.insert(Pair);
+    unsigned &I = Result.first->second;
+    if (Result.second) {
+      Vector.push_back(std::make_pair(KV.first, KV.second));
+      I = Vector.size() - 1;
+      return std::make_pair(llvm::prior(end()), true);
+    }
+    return std::make_pair(begin() + I, false);
+  }
+
   unsigned count(const KeyT &Key) const {
     typename MapType::const_iterator Pos = Map.find(Key);
     return Pos == Map.end()? 0 : 1;

unittests/ADT/MapVectorTest.cpp

@@ -0,0 +1,41 @@
+//===- unittest/ADT/MapVectorTest.cpp - MapVector unit tests ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+#include "llvm/ADT/MapVector.h"
+#include <utility>
+
+using namespace llvm;
+
+TEST(MapVectorTest, insert) {
+  MapVector<int, int> MV;
+  std::pair<MapVector<int, int>::iterator, bool> R;
+
+  R = MV.insert(std::make_pair(1, 2));
+  ASSERT_EQ(R.first, MV.begin());
+  EXPECT_EQ(R.first->first, 1);
+  EXPECT_EQ(R.first->second, 2);
+  EXPECT_TRUE(R.second);
+
+  R = MV.insert(std::make_pair(1, 3));
+  ASSERT_EQ(R.first, MV.begin());
+  EXPECT_EQ(R.first->first, 1);
+  EXPECT_EQ(R.first->second, 2);
+  EXPECT_FALSE(R.second);
+
+  R = MV.insert(std::make_pair(4, 5));
+  ASSERT_NE(R.first, MV.end());
+  EXPECT_EQ(R.first->first, 4);
+  EXPECT_EQ(R.first->second, 5);
+  EXPECT_TRUE(R.second);
+
+  EXPECT_EQ(MV.size(), 2u);
+  EXPECT_EQ(MV[1], 2);
+  EXPECT_EQ(MV[4], 5);
+}