Question

often I use big struct with more than 20 fields which need to be initialized by different values.
Every time I wrote the init function, I was hypochondriac, that I always worried about I miss one field to be assigned a value. So I had to check each field one by one.

I hate this, So I use a CHECK_VAL macro like sample code.
Now if i miss one item in the struct initialization, the compiler will report an error:

a value of type “Check” cannot be used to initialize an entity of type
“int”

My question: whether there are other way to help my problem? The language is C and C++, and the big struct is POD type.

Code Sample

#define DOCHECK 1
#if DOCHECK
typedef struct _Check{
    char k;
} Check;
Check g_check = {'c'};
#define CHECK_DEL Check c1234567;
#define CHECK_VAL (g_check)
#else
#define CHECK_DEL
#define CHECK_VAL
#endif

typedef struct _BigStruct{
    int bar;
    int foo;
    /*...*/
    int f99;
    int f100;
    CHECK_DEL;
}BigStruct;

void initBigStruct(BigStruct* p){
    int a,b,c,d;
    a = b = c = d = 0;
    /*
        many other code to caculate the value of a,b,c,d
    */
    {
        BigStruct tmp = {a,b,c,d, CHECK_VAL};
        *p = tmp;
    }
}

Answer 1

From a language point of view, probably not a lot.

However, GCC has the -Wmissing-field-initializers flag for exactly this situation. I’m sure other compilers offer something similar.