NetBSD/gnu/lib/libg++/include/gen/VQueue.ccP

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1996-03-09 03:00:51 +03:00
// This may look like C code, but it is really -*- C++ -*-
/*
Copyright (C) 1988 Free Software Foundation
written by Doug Lea (dl@rocky.oswego.edu)
This file is part of the GNU C++ Library. This library is free
software; you can redistribute it and/or modify it under the terms of
the GNU Library General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version. This library is distributed in the hope
that it will be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef __GNUG__
#pragma implementation
#endif
#include <stream.h>
#include "<T>.VQueue.h"
<T>VQueue::<T>VQueue(<T>VQueue& b)
:size(b.size), cnt(b.cnt), inp(b.inp), outp(b.outp), s(new <T> [b.size])
{
int j = outp;
for (int i = 0; i < cnt; ++i)
{
s[j] = b.s[j];
if (++j == size) j = 0;
}
}
void <T>VQueue::operator = (<T>VQueue& b)
{
if (&b == this) return;
if (size != b.size)
{
delete [] s;
s = new <T> [b.size];
size = b.size;
}
inp = b.inp; outp = b.outp; cnt = b.cnt;
int j = outp;
for (int i = 0; i < cnt; ++i)
{
s[j] = b.s[j];
if (++j == size) j = 0;
}
}
void <T>VQueue::resize(int newsz)
{
if (newsz < cnt)
error("resize: new size too small");
<T>* news = new <T> [newsz];
int j = outp;
for (int i = 0; i < cnt; ++i)
{
news[i] = s[j];
if (++j == size) j = 0;
}
inp = cnt;
outp = 0;
delete [] s;
s = news;
size = newsz;
}
int <T>VQueue::OK()
{
int v = s != 0; // have space
v &= size >= 0; // a legal size
v &= inp >= 0 && inp <= size; // pointers with bounds
v &= outp >= 0 && outp <= size;
int c = (size + inp - outp) % size;
v &= cnt == size || cnt == c; // correct count
if (!v) error("invariant failure");
return v;
}