AW: [std-proposals] Namespace with access specifiers in class interface

class C {

public:

void printi() { cout << "Value: " << i.var << endl; }

private:

ProtectedData<int, &C::printi> i;

};

With ProtectedData being a template class that creates an private int i.var and is

friends with member function C::printi.

Only for friends it provides access to i.var.

Not sure, if you would be happy with such a solution or what would be missing (if at all) to write a

ProtectedData template (member function pointers can be template arguments, member functions can be friends,

but perhaps both concepts do not work together, as for a friend function you have to specify the declaration,

whereas for a class the class name is enough? Perhaps ProtectedData would use an intermediate class).

Sometimes I'd like to hide data from a subset of class methods while still allowing other methods to access them. Also it would be helpful to set read/write access on class data for certain methods.

Allowing namespaces with access specifiers in class interface would look like this:

class Foo {

namespace {

read_write: [Method_1()];

read_only: [Method_2()];

char data1;

float data2;

};

public:

void Method_1();

void Method_2();

void Method_3();

private: // global to class

int x;

int y;

};