boost crowd.

[Alexey Veselovsky]

WB> How is it not true?
J> dmd -H [file] -c generates the header file for you quite nicely.

ok. Let's a see:

C++ code.

Specification:

// test.hpp file
#ifndef _test_hpp_
#define _test_hpp_

void foo();

struct Boo
{
public:
    void boo();
private:
    struct S {};
};

#endif

Implementation:

// file test.cpp
#include "test.hpp"

struct HelperStruct {}; // private struct for this module only

static void foo_helper() {HelperStruct s;}

void foo() { foo_helper(); }

void Boo::boo() { S ss; foo_helper(); } // method implementation in
implementation side, not in specification!

Module usage:

// file main.cpp
#include "test.hpp"

int main() {
    foo();          // ok
    Boo b;          // ok
    b.boo();        // ok
    Boo::S ss;      // error: struct Boo::S is private
    HelperStruct s; // error: HelperStruct was not declared in this scope
    return 0;
}

Now, let's try this on D:

// Implementation
module test;

public {
    void foo() {foo_helper();}

    struct Boo
    {
    public:
        void boo() {S ss; foo_helper();}
    private:
        struct S {};
    }
}

private {
    struct HelperStruct {};
    void foo_helper() {HelperStruct s;}
}

// Specification (generated by dmd -H test.d -c) -- test.di file
// D import file generated from 'test.d'
module test;
public
{
    void foo() {foo_helper();}

    struct Boo
    {
        public
        {
            void boo() {S ss; foo_helper();}
            private struct S{}
        }
    }
}

private
{
    struct HelperStruct{}
    void foo_helper(){HelperStruct s;}
}

Usage:
import test;

void main() {
    foo();          // ok
    Boo b;          // ok
    b.boo();        // ok
    Boo.S ss;       // ok (wtf?)
    HelperStruct s; // ok (wtf?!)
}


First of all I can't see difference between D's implementation and
generated specification. It looks like copy&paste. At second private
section not protect types from usage from other modules.  Also I can't
write method implementation in different (implementation) file
(without inheritance).

Also there are no compiler check for test.di & test.d conformance.

In D I expect real module system like in Modula or Ada. Or at least as
in C++ (or way to emulate it). But...

PS. DMD32 D Compiler v2.056