Question

I know nesting of namespaces is allowed in C++/CLI. So my question is if we have something like this:

...
namespace one
{
    // blah blah blah
    // ...

    namespace two
    {
        // another set of blah blah blah
        // ...
    }
}

and I need to use some functions and variables in namespace two, do I use:

one::two

or

one.two

Another question is that if I have a statement like

using namespace one;

do I have access to variables and functions in any nested namespaces like

namespace two

I’m asking because, in some programs I have seen (and written), there’s something like:

using namespace System;
using namespace System::Text;
using namespace System::IO;

Isn’t the System namespace supposed to cover the System::Text and System::IO namespaces?

Answer 1

You need to use

one::two::some_variable_or_function

The . operator is for accessing non-static struct/class members. Static members can then again be accessed through the scope resolution operator ::.

If you only would use using System;, you could access the System::Text functions/variables by

Text::some_function_or_variable

using the parent namespace does not imply importing all sub-namespaces.