Re: [Swig-user] Treat Returned Reference as Value

[William S F. <ws...@fu...>]

On 18 May 2017 at 15:05, Jake <jak...@gm...> wrote:

> I feel like I must just be missing this in the documentation somewhere,
> but when a function returns a reference SWIG treats that like a pointer by
> default.  How do we tell it to treat it as a value (i.e. make a copy and
> wrap that)?
>
> For example:
>
> struct Example {
>   int& get(int x, int y);
> };
>
> I want the int copied and not as a SWIG_int_p.
>
>

const int& is marshalled by value in Java/C#. You can thus simply use these
typemaps. There are various ways, but I suggest using %apply:

 %apply const int& { int& } // Everywhere (including input parameters and
on function return)

 %apply const int& { int& Example::get} // Just for this function's return

On 18 May 2017 at 15:14, schullq <sch...@gm...> wrote:

> Do you include "typemaps.i" ?
>
> If not, include it, and take a look a it ([swig folder]/Lib/[your target
> language]/typemaps.i]), you should get your answer here.
>
> typemaps.i is for changing the way a function's parameters are marshalled,
so not of any use for a function's return. You'll notice there are no 'out'
typemaps in this file which is what generates the C code for returning
types from a function.

William