C named array elements

named.c

/*
	Abusing C preprocessor to allow you declare enumerator values for each item of an array, inline of the array definition - so that you don't have to repeat list twice like this:
	
	enum {
		ITEM_ONE,
		ITEM_TWO,
		...
	};
	
	struct type array[] = {
		[ITEM_ONE] = { x },
		[ITEM_TWO] = { x },
		...
	};
	
	
	Need to disable `-Winitializer-overrides` so compile with:
	
		clang item.c -Wno-initializer-overrides -o item
	
	or you could just disable it for the array definition:
	
		#pragma clang diagnostic push
		#pragma clang diagnostic ignored "-Winitializer-overrides"
		
		struct type array[] = { ... };
		
		#pragma clang diagnostic pop
	
	
	Output:
	
		one (6, 8)
		two (9, 2)
		three (77, 2)
		four (4, 18)
	
	
	- CTurt
*/

#include <stdio.h>

// If first element in struct is not a pointer remove `void *` cast
#define BEGIN_ARRAY(prefix) [0] = { (void *)(enum { TABLE_START_##prefix = __LINE__ })0 }
#define ARRAY_ENTRY(prefix, n, f, ...) [__LINE__ - TABLE_START_##prefix - 1] = { f?:(enum { prefix##_##n = __LINE__ - TABLE_START_##prefix - 1 })0, ##__VA_ARGS__ }

struct item {
	char *a;
	int b;
	int c;
};

struct item itemArray[] = {
	BEGIN_ARRAY(ITEM),
	ARRAY_ENTRY(ITEM, ONE, .a = "one", .b = 6, .c = 8),
	ARRAY_ENTRY(ITEM, TWO, .a = "two", .b = 9, .c = 2),
	ARRAY_ENTRY(ITEM, THREE, .a = "three", .b = 77, .c = 2),
	ARRAY_ENTRY(ITEM, FOUR, .a = "four", .b = 4, .c = 18),
};

void info(struct item *item) {
	printf("%s (%d, %d)\n", item->a, item->b, item->c);
}

int main(void) {
	info(&itemArray[ITEM_ONE]);
	info(&itemArray[ITEM_TWO]);
	info(&itemArray[ITEM_THREE]);
	info(&itemArray[ITEM_FOUR]);
	
	return 0;
}