Inline initialization of a struct containing a string array

[Antti Karanta]

Hi!

Is it possible to inline initialize a struct whose one member is a string
array of arbitrary length (terminated w/ a NULL ptr)? What I mean is
something like this:


typedef struct {
char** x ;
int y ;
} Foo ;

static const Foo myfoos[] = {
{ { "hello", "world", NULL }, 12 },
{ NULL, 0 }
} ;


This produces warnings (from mingw gcc) for line w/ "hello" on it:

"initializa tion from incompatible pointer type"
"excess elements in scalar initializer"
"braces around scalar initializer"

So obviously this is not the way to do it, or I am missing something
here? Is
this possible at all?


It works fine if I define the first struct memeber as char* x[ 3 ] ; but
that
is not what I'm after - I need arbitrary length char* arrays.


As a last resort, I can do the initialization in the beginning of main
(i.e. just myfoos[0].x = ptrToFirstStrAr ray ; // ...), but that's not very
pretty...



.::Antti::.



Ps. I did consider "multistrin gs", e.g. "hello\0world\0 ", but that would
be inconsistent w/ the presentation of array of string values used in
other parts of the program.

[Eric Sosman]

Re: Inline initialization of a struct containing a string array

Antti Karanta wrote:

>
>
Hi!
>
Is it possible to inline initialize a struct whose one member is a string
array of arbitrary length (terminated w/ a NULL ptr)? What I mean is
something like this:
>
>
typedef struct {
char** x ;
int y ;
} Foo ;
>
static const Foo myfoos[] = {
{ { "hello", "world", NULL }, 12 },
{ NULL, 0 }
} ;

Define the arrays first, give them names, and use the
names when you initialize the structs.

static const char* fooArray0[] = {
"hello", "world", NULL };
static const char* fooArray1[] = {
"there", "is", "no", "Cabal", NULL };
static const Foo myfoos[] = {
{ fooArray0, 12 },
{ fooArray1, 42 },
{ NULL, 0 } };

It's not as slick as if you could somehow make the arrays
anonymous, but it works.

--
Eric.Sosman@sun .com

[Andrey Tarasevich]

Re: Inline initialization of a struct containing a string array

Antti Karanta wrote:

...
Is it possible to inline initialize a struct whose one member is a string
array of arbitrary length (terminated w/ a NULL ptr)? What I mean is
something like this:
>
>
typedef struct {
char** x ;
int y ;
} Foo ;
>
static const Foo myfoos[] = {
{ { "hello", "world", NULL }, 12 },
{ NULL, 0 }
} ;
...

You can do that in C99 by using compound literals

static const Foo myfoos[] = {
{ (char*[]) { "hello", "world", NULL }, 12 },
{ NULL, 0 }
};

But in C89/90 you'll have to resort to multiple declarations, I believe.

--
Best regards,
Andrey Tarasevich