Orchid Win7 v1 <voi### [at] devnull> wrote:
> And then I read the documentation for our test framework [GTest, in case 
> anybody cares], and it says to do basically the same thing as the above. 
> IOW, make a private class, put it in its own header file, let the test 
> framework include that header file, but nobody else.

In principle if a class or function exists in a namespace that's not
local to a compilation unit (in other words, a nameless namespace inside
a compilation unit), it will be visible globally and could therefore
technically speaking be used by everything else.

Unlike it might seem, header files in C/C++ are not a language feature.
They are not syntax that imposes some kind of semantics (eg. access
restrictions or something like that.) It's not like other code couldn't
use some class or function if it doesn't have access to the header file
that declares them.

Header files are both a convenience and an abstraction tool, but are
strictly speaking unnecessary.

Let's say that you *know* that somewhere in the innards of some compilation
unit (which might be eg. a library) there's a function named 'foo' which
takes an int and returns an int, which is in the global namespace. Even
if you have no access to any header that declares said function, you can
still just write in your own code:

//----------------------------------------------------------------
int foo(int);

void myFunction()
{
    foo(5);
}
//----------------------------------------------------------------

With classes it becomes a bit more complicated because you need to
know the exact contents of the class. However, technically speaking
if you know that you don't need any header file to use it.

Of course all this is mostly theoretical.

-- 
                                                          - Warp

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