Re: Code fails with linker error. Why?

[John Colvin via Digitalmars-d-learn]

On Saturday, 4 October 2014 at 11:01:30 UTC, John Colvin wrote:

On Saturday, 4 October 2014 at 10:38:32 UTC, ketmar via Digitalmars-d-learn wrote:

On Sat, 04 Oct 2014 10:27:16 +0000

John Colvin via Digitalmars-d-learn <digitalmars-d-learn@puremagic.com>

wrote:

Sorry, but that's just not how it works. There is no requirement for the definition of a function to be found in the same compilation unit as it's declaration.

is there any possibility to declare *class* *method* in one file and to

implement it in another? O_O

i doubt so.

Yes, you can. You just have to get the mangling right.

// methodLink.d
class A
{
    void foo();
}

void main()
{
    auto a = new A;
    a.foo();
}

// missingMethod.d
import methodLink;
import std.stdio;

pragma(mangle, A.foo.mangleof)
void foo() { writeln("Hello World"); }

$ dmd missingMethod.d -c
$ dmd methodLink.d missingMethod.o
$ ./methodLink
Hello World

Inheritance works too:

//methodLink.d
import std.stdio;
class Base
{
    void foo() { writeln("From Base"); }
}

class A : Base
{
    override void foo();
}

void main()
{
    Base a = new A;
    a.foo();

    a.Base.foo();
}

$ dmd methodLink.d missingMethod.o
$ ./methodLink
Hello World
From Base