json/include/nlohmann/ordered_map.hpp
gatopeich ddf0a45abb Use AllocatorType<ObjectType::value_type>,
instead of hard-coding it for std::map's value_type
2020-06-22 18:35:46 +01:00

58 lines
1.4 KiB
C++

#pragma once
#include <functional> // less
#include <memory> // allocator
#include <utility> // pair
#include <vector> // vector
namespace nlohmann
{
/// ordered_map: a minimal map-like container that preserves insertion order
/// for use within nlohmann::basic_json<ordered_map>
template <class Key, class T, class IgnoredLess = std::less<Key>,
class Allocator = std::allocator<std::pair<Key, T>>,
class Container = std::vector<std::pair<Key, T>, Allocator>>
struct ordered_map : Container
{
using key_type = Key;
using mapped_type = T;
using typename Container::iterator;
using typename Container::value_type;
using typename Container::size_type;
using Container::Container;
std::pair<iterator, bool> emplace(key_type&& key, T&& t)
{
for (auto it = this->begin(); it != this->end(); ++it)
{
if (it->first == key)
{
return {it, false};
}
}
Container::emplace_back(key, t);
return {--this->end(), true};
}
T& operator[](Key&& key)
{
return emplace(std::move(key), T{}).first->second;
}
size_type erase(const Key& key)
{
for (auto it = this->begin(); it != this->end(); ++it)
{
if (it->first == key)
{
Container::erase(it);
return 1;
}
}
return 0;
}
};
} // namespace nlohmann