designated-initializer

C99 introduced the concept of designated intializers for structs. So for example, given: typedef struct { int c; char a; float b; } X; I could initialize like: X foo = {.a = '\1', .b = 2.0F, .c = 4}; and calling: printf("c = %d\na = %hhu\nb = %f", foo.c, foo.a, foo.b); would output: c = 4 a = 1 b = 2.000000 As mentioned here this has the "surprising behavior" of assigning to c then a then b , independent of the order of my designated initializers. This becomes a real issue if I have functions like this: int i = 0; int f() { return ++i; } int g() { i += 2; return i; } int h() { i += 4; return i

I have a UITableViewController subclass that's instantiated, depending on where it's used, in a NIB or via code. In both cases I want to do customization in the initializer method. Does that mean I need to implement both initWithNibName:bundle: and initWithCoder: , and would each method call its respective super initializer? While I don't need this right now, what if I also want to be able to instantiate the view controller with initWithStyle: ? Would I then need 3 different init methods that replicate the same behavior? It seems like this violates the whole designated initializer convention,

I'm using GCC 4.6.2 (Mingw) and compiling with -Wextra . I'm getting strange warnings whenever I use designated initializers. For the following code typedef struct { int x; int y; } struct1; typedef struct { int x; int y; } struct2; typedef struct { struct1 s1; struct2 s2[4]; } bug_struct; bug_struct bug_struct1 = { .s1.x = 1, .s1.y = 2, .s2[0].x = 1, .s2[0].y = 2, .s2[1].x = 1, .s2[1].y = 2, .s2[2].x = 1, .s2[2].y = 2, .s2[3].x = 1, .s2[3].y = 2, }; I get warnings bug.c:24:3: warning: missing initializer [-Wmissing-field-initializers] bug.c:24:3: warning: (near initialization for 'bug_struct1

Using VS2013 Update 2, I've stumbled on some strange error message : // test.c int main(void) { struct foo { int i; float f; }; struct bar { unsigned u; struct foo foo; double d; }; struct foo some_foo = { .i = 1, .f = 2.0 }; struct bar some_bar = { .u = 3, // error C2440 : 'initializing' : cannot convert from 'foo' to 'int' .foo = some_foo, .d = 4.0 }; // Works fine some_bar.foo = some_foo; return 0; } Both GCC and Clang accept it. Am I missing something or does this piece of code exposes a compiler bug ? EDIT : Duplicate: Initializing struct within another struct using designated initializer

In C99 (and not in C++), it's possible to initialize structs using this syntax: struct info { char name[8+1]; int sz; int typ; }; struct info arr[] = { [0] = { .sz = 20, .name = "abc" }, [9] = { .sz = -1, .name = "" } }; What happens to the unspecified fields? They are zeroed. From the C99 standard §6.7.8 (Initialization)/21, If there are fewer initializers in a brace-enclosed list than there are elements or members of an aggregate, or fewer characters in a string literal used to initialize an array of known size than there are elements in the array, the remainder of the aggregate shall be

Is there any specific reason why has support for designated initializers not been added to g++? Is the reason that C99 standards came late and g++ was developed earlier and later people didn't care about this issue, or there is some inherent difficulty in implementing designated initializers in the grammar of C++? As I noted in a comment, G++ doesn't support C99 standard designated initialisers, but it does support the GNU extension to C90 which allows designated initialisers. So this doesn't work: union value_t { char * v_cp; float v_f; }; union value_t my_val = { .v_f = 3.5f }; But this does

This code worked on first XCode 6 Beta, but on latest Beta it's not working and gives such errors Must call a designated initializer of the superclass SKSpriteNode : import SpriteKit class Creature: SKSpriteNode { var isAlive:Bool = false { didSet { self.hidden = !isAlive } } var livingNeighbours:Int = 0 init() { // throws: must call a designated initializer of the superclass SKSpriteNode super.init(imageNamed:"bubble") self.hidden = true } init(texture: SKTexture!) { // throws: must call a designated initializer of the superclass SKSpriteNode super.init(texture: texture) } init(texture: