For some reason, automatic completion of namespaces is not consistent with other name scopes, such as structs or enums. As you can see on the attached illustrations namespace auto-completion always adds scope resolution operator:: while for other entities it does not. This is too counter intuitive and causes issues when typing quickly: if you're used to adding :: manually, because it is required in case of structs and enums then switching to namespaces is such a pain because it leads to your hands automatically adding extra ::.