constraint.cpp revision 6af8609f35d86944763dc80141002c548984b2ed
/**
* \brief A constraint determines a minimum or exact spacing required between
* two variables.
*
* Authors:
* Tim Dwyer <tgdwyer@gmail.com>
*
* Copyright (C) 2005 Authors
*
* Released under GNU LGPL. Read the file 'COPYING' for more information.
*/
#include "constraint.h"
#include <cassert>
Constraint::Constraint(Variable *left, Variable *right, double gap, bool equality)
: left(left),
right(right),
gap(gap),
timeStamp(0),
active(false),
visited(false),
equality(equality)
{
left->out.push_back(this);
right->in.push_back(this);
}
Constraint::~Constraint() {
Constraints::iterator i;
for(i=left->out.begin(); i!=left->out.end(); i++) {
if(*i==this) break;
}
left->out.erase(i);
for(i=right->in.begin(); i!=right->in.end(); i++) {
if(*i==this) break;
}
right->in.erase(i);
}
std::ostream& operator <<(std::ostream &os, const Constraint &c)
{
if(&c==NULL) {
os<<"NULL";
} else {
const char *type=c.equality?"=":"<=";
os<<*c.left<<"+"<<c.gap<<type<<*c.right<<"("<<c.slack()<<")"<<(c.active?"-active":"");
}
return os;
}