Is there any project organization standard for C ++?

In Java and ActionScript3.0 we use namespaces based on the directory path, I see a lot of use of namespace , but are not based on the path of the "location" class in the folder.

I searched a lot if there was any kind of organization that has that "recommendation" for PHP, the PSR-4, but for C ++ I did not find any recommendations, I know it should be trivial, but I think a minimum of organization, size of the team or be a personal project can be a good way, in the case the intention is not to use namespaces in all classes, only in isolated libs that I will reuse for various applications.

Is there something like this for C ++, an "official" design pattern?

If it does not exist, I thought of doing something like this:

• ./fornecedor/categoria/foo.h

  namespace Fornecedor
  {
      namespace Categoria
      {
          class Foo()
          {
              public:
                  Foo();
          };
      };
  };
  

• ./fornecedor/categoria/foo.cpp

  #include "foo.h"
  
  using namespace Fornecedor::Categoria;
  
  Foo::Foo()
  {
      ...
  }
  

In this example above:

• The class name is associated with the file name
• Files and folders are always in lowercase (lowercase letters)
• Category would only be to divide the use of classes, for example fornecedor/matematica/soma.cpp and fornecedor/matematica/divisao.cpp

This is just an idea, would it be a good way?