Improving flat containers interface.

base/containers/flat_set_unittest.cc

Index: base/containers/flat_set_unittest.cc
diff --git a/base/containers/flat_set_unittest.cc b/base/containers/flat_set_unittest.cc
index dc024fcf0a9729a15d4987e3980da46306a6b143..a42c86c60fbcd2f4956ecc8e74149c88610305d4 100644
--- a/base/containers/flat_set_unittest.cc
+++ b/base/containers/flat_set_unittest.cc
@@ -90,4 +90,28 @@ TEST(FlatSet, CopySwap) {
   EXPECT_THAT(copy, ElementsAre(1, 2));
 }
 
+TEST(FlatSet, UniquePtrs) {
+  using ExplicitInt = base::MoveOnlyInt;
+  base::flat_set<ExplicitInt> s;
+  const auto& s1 = s;
+  int x = 0;
+  s.count(x);

[vmpstr, 2017/06/23 21:45:14]

Can you leave a comment that this is checking if things compile and what exactly
it's checking

+  s1.count(x);
+  s.find(x);
+  s1.find(x);
+  s.equal_range(x);
+  s1.equal_range(x);
+  s.lower_bound(x);
+  s1.lower_bound(x);
+  s.upper_bound(x);
+  s1.upper_bound(x);
+  s.erase(x);
+
+  // Check if we broke overload resolution.
+  s.emplace(0);
+  s.emplace(1);
+  s.erase(s.begin());
+  s.erase(s.cbegin());
+}
+
 }  // namespace base