Initialize an array of union types

Question

Hi,
I'm trying to the use the C99 designated initializer feature to initialize an array of union types, but I'm getting a compiler error as shown below. Am I using the correct syntax?
#include <stdio.h>
union U
     struct {int data;} a;
     struct {int type; float data;} b;
int
main()
     union U x = {.b.type = 2, .b.data = 1.0};
     union U y[] = {{.b.type = 2, .b.data = 1.0}};
     fprintf(stderr, "x b data: %f\n",    x.b.data);
     fprintf(stderr, "y b data: %f\n", y[0].b.data);
     return 0;
}% cc u.c
"u.c", line 13: structure/union designator used on non-struct/union type
"u.c", line 13: structure/union designator used on non-struct/union type
cc: acomp failed for u.c
% cc -Version
cc: Sun C 5.9 DEV 2006/06/08
%

Answer 1

    union U x = { .b = { .type = 2, .data = 1.0 } };
    union U y[] = {{.b = { .type = 2, .data = 1.0}}};