Re: DIP61: redone to do extern(C++,N) syntax

[Regan Heath via Digitalmars-d]

On Wed, 30 Apr 2014 10:20:22 +0100, Regan Heath <re...@netmail.co.nz>  
wrote:

Something else to think about.
C# has the same problem and has solved it the following way..

[main.cs]
using ..
using CSTest_Test1;
using CSTest_Test2;

namespace CSTest
{
    class Program
    {
        static void Main(string[] args)
        {
            Test1.GetLastError(); // class, not namespace required to call  
method
            Test2.GetLastError(); // class, not namespace required to call  
method
        }
    }
}

[Test1.cs]
using ..
namespace CSTest_Test1
{
    public static class Test1
    {
        [DllImport("coredll.dll", SetLastError = true)]
        public static extern Int32 GetLastError();
    }
}

[Test2.cs]
namespace CSTest_Test2
{
    public static class Test2
    {
        [DllImport("coredll.dll", SetLastError = true)]
        public static extern Int32 GetLastError();
    }
}

GetLastError() is always going to unambiguous here because it *must* live  
inside a C# class and that class name is *always* required in the call to  
it.

If D has replaced classes/namespaces with modules, then the answer to our  
problem may be to use the C++ namespace *only* to mangle the symbol, and  
*only* use the D module for lookup resolution.

module a;
extern(C++, std) class string {..}

module b:
extern(C++, std) class string {..}
extern(C++, std) class vector {..}

module userland;
import a;
import b;

void main()
{
  string x = new string();     //error ambiguous (same resolution as for D  
symbols)
  a.string x = new a.string(); //ok
  b.vector y = new b.vector(); //ok
}

Regan