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[];
};
```
```d
struct test1 {
test1 *prev;
test1 *next;
size_t v1;
size_t v2;
size_t v3;
char* data;
};
```
when I compare the size, test1.sizeof is 48 and sizeof(struct
test1) from C is 40.
Anyone can explain what should I do with this ?
If I use test1 as member of other struct, the total size will
not match.
`char data[]` in the C struct is not a pointer, but actually a
[C99 flexible array member][1], and does not count towards the
struct's `sizeof`.
D does not have flexible array members, but you can simulate one
using a struct method:
```d
struct test1 {
// member variables...
char* data() {
return cast(char*) (&this + 1);
}
}
```
[1]: http://port70.net/~nsz/c/c99/n1256.html#6.7.2.1p16
