glibc/bits/stdlib-bsearch.h

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2013-02-12 06:18:09 +08:00
/* Perform binary search - inline version.
Copyright (C) 1991-2017 Free Software Foundation, Inc.
2013-02-12 06:18:09 +08:00
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
__extern_inline void *
bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
__compar_fn_t __compar)
{
size_t __l, __u, __idx;
const void *__p;
int __comparison;
__l = 0;
__u = __nmemb;
while (__l < __u)
{
__idx = (__l + __u) / 2;
__p = (void *) (((const char *) __base) + (__idx * __size));
__comparison = (*__compar) (__key, __p);
if (__comparison < 0)
__u = __idx;
else if (__comparison > 0)
__l = __idx + 1;
else
return (void *) __p;
}
return NULL;
}