aggregate-initialization

class C { public: C() : arr({1,2,3}) //doesn't compile {} /* C() : arr{1,2,3} //doesn't compile either {} */ private: int arr[3]; }; I believe the reason is that arrays can be initialized only with = syntax, that is: int arr[3] = {1,3,4}; Questions How can I do what I want to do (that is, initialize an array in a constructor (not assigning elements in the body)). Is it even possible? Does the C++03 standard say anything special about initializing aggregates (including arrays) in ctor initializers? Or the invalidness of the above code is a corollary of some other rules? Do C++0x initializer

Is it allowed in standard: struct A { int a = 3; int b = 3; }; A a{0,1}; // ??? Is this class still aggregate? clang accepts this code, but gcc doesn't. In C++11 having in-class member initializers makes the struct/class not an aggregate — this was changed in C++14, however. This is something I found surprising when I first ran into it, the rationale for this restriction is that in-class initializers are pretty similar to a user defined constructor but the counter argument is that no one really expects that adding in-class initializers should make their class/struct a non-aggregate, I sure did