On Friday, 30 July 2021 at 14:05:58 UTC, workman wrote:
I get want to define this struct in D:
```c
struct test1 {
struct test1 *prev;
struct test1 *next;
size_t v1;
size_t v2;
size_t v3;
char data[];
};
```
The easy way: put a slice there instead of a fake array and
accept that data's contents will be allocated separately. Slices
will be more convenient to deal with in the language anyway.
The C89 way: add a zero-length array and deal with its .ptr in
appropriately sized allocations that you manage yourself (or get
from a C API).
A third way: something with
https://dlang.org/phobos/core_lifetime.html#.emplace
```d
import core.memory : pureMalloc, pureFree;
import std.conv : to;
struct Pascal {
ubyte len;
char[0] data;
static Pascal* alloc(string s) {
const len = s.length.to!ubyte;
auto res = cast(Pascal*) pureMalloc(Pascal.sizeof + len);
res.len = len;
res.data.ptr[0 .. len] = s[0 .. len];
return res;
}
char[] toString()() {
return data.ptr[0 .. len];
}
}
unittest {
auto s = Pascal.alloc("hello");
scope (exit) pureFree(s);
assert(s.toString == "hello");
assert((*s).sizeof == ubyte.sizeof);
}
```
