// Copyright 2021 The Tint Authors.
//
// 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 SRC_SEM_BINDING_POINT_H_
#define SRC_SEM_BINDING_POINT_H_

#include <stdint.h>

#include <functional>

#include "src/utils/hash.h"

namespace tint {
namespace sem {

/// BindingPoint holds a group and binding index.
struct BindingPoint {
  /// The `[[group]]` part of the binding point
  uint32_t group = 0;
  /// The `[[binding]]` part of the binding point
  uint32_t binding = 0;

  /// Equality operator
  /// @param rhs the BindingPoint to compare against
  /// @returns true if this BindingPoint is equal to `rhs`
  inline bool operator==(const BindingPoint& rhs) const {
    return group == rhs.group && binding == rhs.binding;
  }

  /// Inequality operator
  /// @param rhs the BindingPoint to compare against
  /// @returns true if this BindingPoint is not equal to `rhs`
  inline bool operator!=(const BindingPoint& rhs) const {
    return !(*this == rhs);
  }
};

}  // namespace sem
}  // namespace tint

namespace std {

/// Custom std::hash specialization for tint::sem::BindingPoint so
/// BindingPoints can be used as keys for std::unordered_map and
/// std::unordered_set.
template <>
class hash<tint::sem::BindingPoint> {
 public:
  /// @param binding_point the binding point to create a hash for
  /// @return the hash value
  inline std::size_t operator()(
      const tint::sem::BindingPoint& binding_point) const {
    return tint::utils::Hash(binding_point.group, binding_point.binding);
  }
};

}  // namespace std

#endif  // SRC_SEM_BINDING_POINT_H_