Allocating struct with variable length array member

Question

I know I can do new char[n] to create an array of n chars. This works even when n is not a compile time constant.

But lets say

Answer 1

You can also use the "Length 1 Array" trick. This is in C:

struct Test {
    size_t size;
    char a[1];
}

int want_len = 2039;
struct Test *test = malloc(sizeof(struct Test) + (want_len - 1));
test->size = want_len;

GCC also supports "0 length" arrays for exactly this purpose: http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html