public bool TryPeek(int lookahead, out T value)
{
if (_Disposed == _state)
{
throw new ObjectDisposedException(GetType().Name);
}
if (0 > lookahead)
{
throw new ArgumentOutOfRangeException(nameof(lookahead));
}
if (_Ended == _state)
{
value = default(T);
return(false);
}
if (0 == lookahead)
{
if (_NotStarted == _state)
{
if (!MoveNext())
{
value = default(T);
return(false);
}
_state = _FirstRead;
}
value = _queue.Peek();
return(true);
}
bool read = false;
value = default(T);
while (_queue.Count <= lookahead)
{
if (!_inner.MoveNext())
{
if (0 == _queue.Count)
{
_state = _Ended;
}
value = default(T);
return(false);
}
value = _inner.Current;
_queue.Enqueue(value);
read = true;
}
// if this is our first peek out this far we shortcutted because we just read it so we return it
if (read)
{
return(true);
}
value = _queue[lookahead];
return(true);
}
