How to initialize std::array in class definition?

Question

Since C++11, it is possible to initialize member variables in class definitions:

class Foo {
   int i = 3;
}

I know I can initialize an std::array like this:

std::array<float, 3> phis = {1, 2, 3};

How can I do this in a class definition? The following code gives an error:

class Foo {
    std::array<float, 3> phis = {1, 2, 3};
}

GCC 4.9.1:

error: array must be initialized with a brace-enclosed initializer 
std::array<float, 3> phis = {1, 2, 3};
                                     ^ error: too many initializers for 'std::array<float, 3ul>'

Answer 1

You need one more set of braces, which is non-intuitive.

std::array<float, 3> phis = {{1, 2, 3}};