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最新推荐文章于 2023-10-26 21:01:27 发布

chifengtuan3409

最新推荐文章于 2023-10-26 21:01:27 发布

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原文链接：https://my.oschina.net/innovation/blog/3083269

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本文详细介绍了C语言中Akobject结构的定义与使用，包括其类型、字段及通过宏进行内容访问与修改的方法。此外，还展示了如何通过特定宏创建与复制字符串。

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In C, typedef K represents a k object. It is a pointer to a
struct containing the following fields + content specific data:

c   ref count
n   number of items
t   type of the object

These can be directly accessed from C code but should never be
directly modified. Object content should only be accessed
or modified through macros described below.

A k object can be of the following types (the first column
shows the value in t field).

K KK(K)
    KK() takes a general list and retuns a ptr to an array of
    objects.


#define KK(x) ((K*)((x)->k))

KK(d)[0] = gsk("foo", gi(12));

Z I ns = 0, sd = 0;
// Z S sdup(S s){R strdupn(s,strlen(s));} //using this because "strdup" uses
// [used] dynamically linked malloc which fails with our static free
Z S sdupI(S s) {
  I k;
  S d = alloc(NSLOTS * sizeof(I) + (k = strlen(s)) + 1);
  if (!d)
    R 0;
  ns++;
  sd = 1;
  d += NSLOTS * sizeof(I);
  d[k] = 0;
  R memcpy(d, s, k);
}

转载于:https://my.oschina.net/innovation/blog/3083269