Can I ignore the gcc warning: ‘Foo::m_bar’ should be initialized in the member initialization list [-Weffc++]

struct Bar
{
    Bar() {}
};


struct Foo
{
    Foo() = default;
    Bar m_bar;
};

int main()
{
    Foo foo;
}

When using C++11 default keyword and gcc warning -Weffc++, gcc outputs:

warning: ‘Foo::m_bar’ should be initialized in the member initialization list [-Weffc++]

Is it safe to ignore this warning? Should I file a bug to gcc?