syntax - Is there a better way to express nested namespaces in C++ within the header

Question

I switched from C++ to Java and C# and think the usage of namespaces/packages is much better there (well structured). Then I came back to C++ and tried to use namespaces the same way but the required syntax is horrible within the header file.

namespace MyCompany
{
    namespace MyModule
    {
        namespace MyModulePart //e.g. Input
        {
            namespace MySubModulePart
            {
                namespace ...
                {
                    public class MyClass    

The following seems strange to me too (to avoid the deep indent):

namespace MyCompany
{
namespace MyModule
{
namespace MyModulePart //e.g. Input
{
namespace MySubModulePart
{
namespace ...
{
     public class MyClass
     {

Is there a shorter Way to express the above thing? I am missing something like

namespace MyCompany::MyModule::MyModulePart::...
{
   public class MyClass

Update

Ok, some say the concept of usage in Java/C# and C++ is different. Really? I think (dynamic) class loading is not the only purpose for namespaces (this is a very technical reasoned perspective). Why shouldn't I use it for a readability and structurization, e.g think of "IntelliSense".

Currently, there is no logic / glue between a namespace and what you can find there. Java and C# does this much better... Why including <iostream> and having namespace std? Ok, if you say the logic should rely on the header to include, why does the #include does not uses an "IntelliSense" friendly syntax like #include <std::io::stream> or <std/io/stream>? I think the missing structurization in the default libs is one weakness of C++ compared to Java/C#.

If uniqueness to avid conflicts is one Point (which is a point of C# and Java, too) a good idea is to use the project name or company name as namespace, don't you think so?

On the one hand it's said C++ is the most flexible... but everyone said "don't do this"? It seems to me C++ can do many things but has a horrible syntax even for the easiest things in many cases compared to C#.

Update 2

Most users say it is nonsense to create a deeper nesting than two Levels. Ok, so what about Windows::UI::Xaml and Windows::UI::Xaml::Controls::Primitives namespaces in Win8 development? I think Microsoft's usage of namespaces makes sense and it is indeed deeper than just 2 Levels. I think bigger libraries / projects need a deeper nesting (I hate class names like ExtraLongClassNameBecauseEveryThingIsInTheSameNameSpace... then you could put everything into the global namespace, too.)

Update 3 - Conclusion

Most say "don't do it", but... even boost has a deeper nesting then one or two levels. Yes, it is a library but: If you want reusable code - treat your own code like a library you would give someone else. I also use a deeper nesting for discovery purposes using namespaces.

Answer 1

C++17 might simplify nested namespace definition:

namespace A::B::C {
}

is equivalent to

namespace A { namespace B { namespace C {
} } }

See (8) on namespace page on cppreference:
http://en.cppreference.com/w/cpp/language/namespace