/usr/include/eclib/bitspace.h is in libec-dev 20160720-2.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 | // bitspace.h: declaration of class bitspace for handling F_2 spaces
//////////////////////////////////////////////////////////////////////////
//
// Copyright 1990-2012 John Cremona
//
// This file is part of the eclib package.
//
// eclib is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2 of the License, or (at your
// option) any later version.
//
// eclib 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 General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License
// along with eclib; if not, write to the Free Software Foundation,
// Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
//
//////////////////////////////////////////////////////////////////////////
class bitspace {
private:
long maxdim;
long dim;
long * pivs; // holds the position of the ith pivot
unsigned long * gens; // holds the ith basis element
unsigned long bitmask; // holds the bits of the pivs
public:
bitspace(long d);
~bitspace();
unsigned long getbitmask() {return bitmask;}
long reduce(unsigned long& v, long start=0) const;
// reduces v mod this, returns minimal i such that the reduced v has
// ith bit set, or -1 if v reduces to 0. Assumes already reduced for i<start
int mask(unsigned long i) {return (i&bitmask)!=0;}
void augment(unsigned long v, long piv);
// uses reduced v to augment this, given piv as suitable pivot position in v
int augment(unsigned long v)
// uses v to augment this unless it it dependent, returns 1 if new
{
long j = reduce(v);
if(j<0) return 0;
augment(v,j); return 1;
}
};
inline int testbit(long a, long i) {return (a& (1<<i));}
inline int setbit( long& a, long i) {return (a|=(1<<i));}
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