most vexing parse prevents in-class initializing a std::vector

Question

C++11 allows in-class initialization:

struct Foo{
    std::vector v{3}; // vector of 3 empty strings
};

If we wanted to

Answer 1

Default member initializers work with = as well. So

struct Foo{
    std::vector<int> v = std::vector<int>(3);
};

Will do it. Though obviously, a major caveat is the fact that we are repeating the type name here.

We can alleviate it somewhat with decltype:

struct Foo{
    std::vector<int> v = decltype(v)(3);
};

But that still has us naming things twice.