// Copyright 2003, Trustees of Indiana University
// Please see the license in the file ../LICENSE

// Function concepts:
public interface UnaryFunction<T> {
  T op(T a);
}

public interface BinaryFunction<T> {
  T op(T a, T b);
}

public interface StrictWeakOrdering<T> {
  bool less(T a, T b);
}

// Queue concepts:
public interface Buffer<Value> {
  void push(Value v);
  Value pop();
  bool empty();
}

public interface MutableQueue<Vertex>: Buffer<Vertex> {
  void update(Vertex v);
}

// Property map concepts:
public interface ReadablePropertyMap<Key,Value> {
  Value this[Key k] {get;}
}

public interface ReadWritePropertyMap<Key,Value>
    : ReadablePropertyMap<Key,Value> 
{
  new Value this[Key k] {get; set;}
}