Can't autocomplete a method of template class when the method is defined in a namespace outside class declaration

// declare class template
template <typename T>
class Foo
{
    void bar(); 
}; 

// define class method
template <typename T> 
void Foo<T>::bar() // bar is successfully autocompleted
{}

namespace foo_bar {

template <typename T>
class Foo
{
    void bar(); 
}; 

// 
template <typename T> 
void Foo<T>::bar() // bar IS NOT autocompleted
{}

}

namespace foo_bar {

template <typename T>
class Foo
{
    void bar();
};

}

// either

template <typename T>
void foo_bar::Foo<T>::bar() // bar is successfully autocompleted
{}

// or

using namespace foo_bar;

template <typename T>
void Foo<T>::bar() // bar is successfully autocompleted
{}