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// FILE: queue1.template
// TEMPLATE CLASS IMPLEMENTED: queue<Item> (see queue1.h for documentation)
// This file is included in the header file, and not compiled separately.
// INVARIANT for the queue class:
// 1. The number of items in the queue is in the member variable count;
// 2. For a non-empty queue, the items are stored in a circular array
// beginning at data[front] and continuing through data[rear].
// The array's total capacity of the array is CAPACITY.
// 3. For an empty array, rear is some valid index, and front is
// always equal to next_index(rear).
//
#include <cassert> // Provides assert
namespace main_savitch_8B
{
template <class Item>
const typename queue<Item>::size_type queue<Item>::CAPACITY;
template <class Item>
queue<Item>::queue( )
{
count = 0;
first = 0;
last = CAPACITY - 1;
}
template <class Item>
Item queue<Item>::front( ) const
// Library facilities used: cassert
{
assert(!empty( ));
return data[first];
}
template <class Item>
void queue<Item>::pop( )
// Library facilities used: cassert
{
assert(!empty( ));
first = next_index(first);
--count;
}
template <class Item>
void queue<Item>::push(const Item& entry)
// Library facilities used: cassert
{
assert(size( ) < CAPACITY);
last = next_index(last);
data[last] = entry;
++count;
}
}
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