add emplace to folly sorted_vector_map

Summary: add emplace for folly::sorted_vector_map

Reviewed By: yfeldblum

Differential Revision: D15789529

fbshipit-source-id: 2afccd4553cc53afd0e92729841120722f72b1ae

folly/sorted_vector_types.h

@@ -855,6 +855,22 @@ class sorted_vector_map : detail::growth_policy_wrapper<GrowthPolicy> {
     insert(ilist.begin(), ilist.end());
   }
 
+  // emplace isn't better than insert for sorted_vector_map, but aids
+  // compatibility
+  template <typename... Args>
+  std::pair<iterator, bool> emplace(Args&&... args) {
+    value_type v(std::forward<Args>(args)...);
+    return insert(std::move(v));
+  }
+
+  std::pair<iterator, bool> emplace(const value_type& value) {
+    return insert(value);
+  }
+
+  std::pair<iterator, bool> emplace(value_type&& value) {
+    return insert(std::move(value));
+  }
+
   size_type erase(const key_type& key) {
     iterator it = find(key);
     if (it == end()) {

folly/test/sorted_vector_test.cpp

@@ -303,6 +303,21 @@ TEST(SortedVectorTypes, SimpleMapTest) {
   EXPECT_TRUE(m3 == m2);
   EXPECT_FALSE(m3 == m);
 
+  sorted_vector_map<int, float> m4;
+  m4.emplace(1, 2.0f);
+  m4.emplace(3, 1.0f);
+  m4.emplace(2, 1.5f);
+  check_invariant(m4);
+  EXPECT_TRUE(m4.size() == 3);
+
+  sorted_vector_map<int, float> m5;
+  for (auto& kv : m2) {
+    m5.emplace(kv);
+  }
+  check_invariant(m5);
+  EXPECT_TRUE(m5 == m2);
+  EXPECT_FALSE(m5 == m);
+
   EXPECT_TRUE(m != m2);
   EXPECT_TRUE(m2 == m3);
   EXPECT_TRUE(m3 != m);
@@ -318,9 +333,9 @@ TEST(SortedVectorTypes, SimpleMapTest) {
   m.insert(m.begin() + 3, std::make_pair(1 << 15, 1.0f));
   check_invariant(m);
 
-  sorted_vector_map<int, float> m4 = {};
-  m4.insert({{1, 1.0f}, {2, 2.0f}, {1, 2.0f}});
-  EXPECT_EQ(m4.at(2), 2.0f);
+  sorted_vector_map<int, float> m6 = {};
+  m6.insert({{1, 1.0f}, {2, 2.0f}, {1, 2.0f}});
+  EXPECT_EQ(m6.at(2), 2.0f);
 }
 
 TEST(SortedVectorTypes, TransparentMapTest) {