Re: luajit: any way to make array initialization zero-based?

[Dimiter 'malkia' Stanev <malkia@...>]

Uh. Yes :)

I should've tried this first, but thought it might not work.

Well, thanks for that one!

On 6/13/2012 8:36 PM, Daurnimator wrote:
> On 14 June 2012 12:47, Dimiter 'malkia' Stanev<malkia@gmail.com>  wrote:
> > How about this workaround (ugly, but still could work):
> >
> > local ffi = require( "ffi" )
> >
> > ffi.cdef[[
> >    typedef struct vec3 {
> >      float x, y, z;
> >    } vec3;
> > ]]
> >
> > local a = ffi.new( "vec3[?]", 1024 + 1 )
> > local b = ffi.cast( "vec3*", ffi.cast("size_t", a) - ffi.sizeof("vec3"))
> >
> > print(a)
> > print(b)
> >
> > for k = 1, 30 do
> >    b[k].x = k
> > end
> >
> > for k = 0, 29 do
> >    print( a[k].x )
> > end
> >
> > The trick here is that 'a' has to be kept, so that 'b' would work (not sure,
> > Mike would know better)
>
> Why not just use pointer arithmetic?
> b = a-1
>
> Same rule for keeping a around applies.