Question

If you use namespaces for separation of modules / structurization the nesting and indentation within the the header file increases dramatically. Is there a way to write the following code in a shorter way?

namespace A
{
    namespace B
    {
        namespace C
        {
            namespace D
            {
                namespace E
                {
                    template <typename T>
                    public class X
                    {
                        public: ...

e.g. like

namespace A::B::C::D::E
{
  template<typename T> ...
}

in the header file in c++?

Answer 1

No, that nested namespace syntax has been suggested before at different times and places but isn’t valid.

You don’t need to indent though

namespace A { namespace B { namespace C {
// ...
} } } // namespace A::B::C