Question

i wrote this program in VC++ 2010:

class class1
{
public:
 class1 (initializer_list<int> a){};
 int foo;
 float Bar;
};
void main()
{
 class1 c = {2,3};
 getchar();
}

but i get this errors when i compile project:

Error 1 error C2552: ‘c’ :
non-aggregates cannot be initialized
with initializer
list c:\users\pswin\documents\visual
studio
2010\projects\test_c++0x\test_c++0x\main.cpp 27

and

2 IntelliSense: initialization with
‘{…}’ is not allowed for object of
type
“class1” c:\users\pswin\documents\visual
studio
2010\projects\test_c++0x\test_c++0x\main.cpp 27

what is the problem?

Answer 1

It shouldn’t be supported at all:

[…] the C++0x Core Language feature of initializer lists and the associated Standard Library changes weren’t implemented in VC10.

The error message refers to the pre-C++0x feature of aggregate initialization, which allows the initialization of certain user-defined types by using curly braces:

struct pair { int first; char second; };
pair p = { 0, 'c' };

Aggregates are defined in §8.5.1:

An aggregate is an array or a class (clause 9) with no user-declared constructors (12.1), no private or protected non-static data members (clause 11), no base classes (clause 10), and no virtual functions (10.3).

When an aggregate is initialized the initializer can contain an initializer-clause consisting of a brace- enclosed, comma-separated list of initializer-clauses for the members of the aggregate, written in increasing subscript or member order. If the aggregate contains subaggregates, this rule applies recursively to the members of the subaggregate.