Improving flat containers interface.

base/template_util_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/template_util.h"
 
 #include <string>
 
+#include "base/containers/flat_tree.h"
+#include "base/test/move_only_int.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace {
 
 enum SimpleEnum { SIMPLE_ENUM };
 enum EnumWithExplicitType : uint64_t { ENUM_WITH_EXPLICIT_TYPE };
 enum class ScopedEnum { SCOPED_ENUM };
 enum class ScopedEnumWithOperator { SCOPED_ENUM_WITH_OPERATOR };
 std::ostream& operator<<(std::ostream& os, ScopedEnumWithOperator v) {
@@ skipping 44 matching lines @@
               "simple struct should not be printable by value");
 static_assert(!internal::SupportsOstreamOperator<const SimpleStruct&>::value,
               "simple struct should not be printable by const ref");
 static_assert(internal::SupportsOstreamOperator<StructWithOperator>::value,
               "struct with operator<< should be printable by value");
 static_assert(
     internal::SupportsOstreamOperator<const StructWithOperator&>::value,
     "struct with operator<< should be printable by const ref");
 
 }  // namespace
+
+TEST(Functors, Less) {

[danakj, 2017/06/27 23:48:25]

nit: TemplateUtil.Less would be easier to find

[dyaroshev, 2017/06/28 09:13:59]

Done.

+  using ExplicitInt = base::MoveOnlyInt;
+  EXPECT_TRUE(base::less()(ExplicitInt(3), 4));
+  EXPECT_FALSE(base::less()(4, ExplicitInt(3)));
+  EXPECT_TRUE(base::less()(3, 4));
+
+  static_assert(base::internal::IsTransparentCompare<base::less>::value, "");
+}
+
 }  // namespace base