Question

Is there a way in C++ to create an anonymous namespace, and only export a single function out of it?

I want something like:

namespace {
  void Bar() {}
  void Foo() { Bar(); }
}

Now, I want to somehow access to Foo() yet make sure there’s no way to touch Bar()

Thanks!

Answer 1

Since you want Foo() to have external linkage, you should declare it in a header file:

#ifndef FOO_H
#define FOO_H

void Foo();

#endif

Now everyone can see and call Foo()

But in Foo.cpp:

#include "Foo.h"

namespace {
    void Bar(){ }
}

void Foo(){ Bar(); }

Now, as long as you control the source file Foo.cpp, no one can change access to Bar()