//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#pragma once
#include "td/utils/common.h"
#include <limits>
#include <map>
#include <tuple>
namespace td {
template <class ValueT>
class Enumerator {
public:
using Key = int32;
Key add(ValueT v) {
CHECK(arr_.size() < static_cast<size_t>(std::numeric_limits<int32>::max() - 1));
int32 next_id = static_cast<int32>(arr_.size() + 1);
bool was_inserted;
decltype(map_.begin()) it;
std::tie(it, was_inserted) = map_.emplace(std::move(v), next_id);
if (was_inserted) {
arr_.push_back(&it->first);
}
return it->second;
const ValueT &get(Key key) const {
auto pos = static_cast<size_t>(key - 1);
CHECK(pos < arr_.size());
return *arr_[pos];
private:
std::map<ValueT, int32> map_;
std::vector<const ValueT *> arr_;
};
} // namespace td
