Re: luajit-ffi

[so]

On Tuesday, 1 May 2012 at 16:56:48 UTC, Alex Rønne Petersen
wrote:

Yes, creating manual bindings is tedious and annoying to maintain, but

it is the most foolproof approach.

In another language there may not be other exit but D, i am not sure.

As it happens, you are safe with D even if you pick that path.
With my limited knowledge, these a few lines of code destroys
all lua binders out there. Make sure they are inlined and it
would be identical to handcrafted bindings.

WARNING: DO NOT TRY THIS WITH C++! (See the "alias F"?
ParamTuple? Yep)

import std.stdio;
import std.traits;

struct handle {
        int i=0;
        int get_arg() {
                return i++;
        }
}

alias handle* hnd;

void assign(uint N, P...)(ref P p, hnd h)
{
        static if(N)
        {
                p[N-1] = h.get_arg();
                assign!(N-1)(p, h);
        }
}

int fn(alias F)(hnd h)
{
        alias ParameterTypeTuple!(typeof(&F)) P;
        P p;

        assign!(P.length)(p, h);
        F(p);
        return 0;
}

// test >>>>
void fun0(int a)
{
        writeln("fun0 a: ", a);
}

void fun1(int a, int b)
{
        writeln("fun1 a: ", a);
        writeln("fun1 b: ", b);
}

void main()
{
//      reg(&fn!fun0, "fun0");
//      reg(&fn!fun1, "fun1");
        auto f0 = &fn!fun0;
        auto f1 = &fn!fun1;
        handle h;
        f0(&h);
        f1(&h);
}
// test <<<<