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

[Daurnimator <quae@...>]

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.