nativecall++.pl

use v6;
use NativeCall;
use Test;

class b2Vec2 is repr<CStruct> { }

my role NativeCallSymbol[Str $name] {
    method native_symbol()  { $name }
}

multi trait_mod:<is>(Routine $r, :$cppsym!) {
    my $mangled = '_ZN'
                ~ $cppsym.split('::').map({$_.chars ~ $_}).join('')
                ~ 'EPK';

    for $r.signature.params».type {
        when int32 {
            $mangled ~= 'i'
        }
        default {
            my $name  = .^name;
            $mangled ~= $name.chars ~ $name;
        }
    }
    $r does NativeCallSymbol[$mangled];
}

sub foo(b2Vec2, int32) is native("libBox2D") is cppsym<b2PolygonShape::Set> { * } # _ZN14b2PolygonShape3SetEPK6b2Vec2i

foo(b2Vec2, 3);