1 // Copyright (c) 2011-present, Facebook, Inc. All rights reserved. 2 // This source code is licensed under both the GPLv2 (found in the 3 // COPYING file in the root directory) and Apache 2.0 License 4 // (found in the LICENSE.Apache file in the root directory). 5 6 #pragma once 7 8 namespace ROCKSDB_NAMESPACE { 9 // A comparator to be used in std::set 10 struct SetComparator { SetComparatorSetComparator11 explicit SetComparator() : user_comparator_(BytewiseComparator()) {} SetComparatorSetComparator12 explicit SetComparator(const Comparator* user_comparator) 13 : user_comparator_(user_comparator ? user_comparator 14 : BytewiseComparator()) {} operatorSetComparator15 bool operator()(const Slice& lhs, const Slice& rhs) const { 16 return user_comparator_->Compare(lhs, rhs) < 0; 17 } 18 19 private: 20 const Comparator* user_comparator_; 21 }; 22 } // namespace ROCKSDB_NAMESPACE 23