gmp_sub
gmp_testbit will be very useful for my (over 64-bit) bitmask checking.
In the meantime, I think these are the best replacements.
Mostly full:
<?php
(gmp_scan1($a, $index) == $index)
?>
Mostly empty:
<?php
(gmp_scan0($a, $index) != $index)
?>
Still worst-case O(N), though.
gmp_testbit
(PHP 5 >= 5.3.0)
gmp_testbit — Tests if a bit is set
说明
bool gmp_testbit
( resource
$a
, int $index
)Tests if the specified bit is set.
参数
-
a -
可以是一个 GMP 数据 resouce，或一个可以转换为数值的字符串。
-
index -
The bit to test
返回值
成功时返回 TRUE， 或者在失败时返回 FALSE。
错误／异常
E_WARNING is issued when
index is less than zero.
范例
Example #1 gmp_testbit() example
<?php
$n = gmp_init("1000000");
var_dump(gmp_testbit($n, 1));
gmp_setbit($n, 1);
var_dump(gmp_testbit($n, 1));
?>
以上例程会输出：
bool(false) bool(true)
add a note
User Contributed Notes
gmp_testbit - [1 notes]
bluej100@gmail ¶
5 years ago