// Copyright 2018 Google LLC

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#ifndef CC_TINY_SET_H_

#define CC_TINY_SET_H_

#include "cc/inline_vector.h"

namespace minigo {

// tiny_set is a very simple set-like container that uses inline storage.

// Since insertions into the set are O(N), tiny_set should only be used for a

// very small number of elements.

// The Position code uses tiny_sets to keep track of neighboring groups of a

// point on the board.

template <typename T, int Capacity>

class tiny_set : private inline_vector<T, Capacity> {

using impl = inline_vector<T, Capacity>;

public:

using impl::begin;

using impl::empty;

using impl::end;

using impl::size;

using impl::operator[];

// Insert an element into the set.

// Returns true if the insertion took place, or false if the element was

// already preset in the set.

bool insert(const T& x) {

for (const auto& y : *this) {

if (x == y) {

return false;

}

}

impl::push_back(x);

return true;

}

};

} // namespace minigo

#endif // CC_TINY_SET_H_