Re: tostring operator doesn't compile if argument is non const

--===============7973288051008614511==
Content-Type: multipart/alternative; boundary=047d7b5dbbe4fb7b4504da9ddcf5

--047d7b5dbbe4fb7b4504da9ddcf5
Content-Type: text/plain; charset=ISO-8859-1

Mutating streaming operator is not idiomatic anyway and will cause problems
in other C++ code. Why do you need it to be mutating?


2013/4/10 Lorenzo Pistone <[email protected]>

> Hello,
> the example in the docs to bind the tostring operator
> (http://www.rasterbar.com/products/luabind/docs.html#operators) doesn't
> compile. I write it here for reference:
>
>      #include <luabind/luabind.hpp>
>      #include <luabind/operator.hpp>
>      #include <ostream>
>      class number {};
>      std::ostream& operator<<(std::ostream& o, number&){ return o; }
>      int main(){
>          lua_State* L = NULL;
>          using namespace luabind;
> module(L)[class_<number>("number").def(tostring(self))];
>      }
>
> It compiles only if you put use this signature for <<:
>
> std::ostream& operator<<(std::ostream& out, const A&)
>
> Also, I would expect that const_self is required in the def, but it
> seems that it doesn't matter. Is this intended behaviour or a bug?
>
> Cheers.
>
>
> ------------------------------------------------------------------------------
> Precog is a next-generation analytics platform capable of advanced
> analytics on semi-structured data. The platform includes APIs for building
> apps and a phenomenal toolset for data science. Developers can use
> our toolset for easy data analysis & visualization. Get a free account!
> http://www2.precog.com/precogplatform/slashdotnewsletter
> _______________________________________________
> luabind-user mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/luabind-user
>



-- 
Szymon Gatner
The Lordz Games Studio
www.thelordzgamesstudio.com

--047d7b5dbbe4fb7b4504da9ddcf5
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Mutating streaming operator is not idiomatic anyway and wi=
ll cause problems in other C++ code. Why do you need it to be mutating?</di=
v><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">2013/4/10 L=
orenzo Pistone <span dir=3D"ltr">&lt;<a href=3D"mailto:[email protected]=
om" target=3D"_blank">[email protected]</a>&gt;</span><br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">Hello,<br>
the example in the docs to bind the tostring operator<br>
(<a href=3D"http://www.rasterbar.com/products/luabind/docs.html#operators" =
target=3D"_blank">http://www.rasterbar.com/products/luabind/docs.html#opera=
tors</a>) doesn&#39;t<br>
compile. I write it here for reference:<br>
<br>
=A0 =A0 =A0#include &lt;luabind/luabind.hpp&gt;<br>
=A0 =A0 =A0#include &lt;luabind/operator.hpp&gt;<br>
=A0 =A0 =A0#include &lt;ostream&gt;<br>
=A0 =A0 =A0class number {};<br>
=A0 =A0 =A0std::ostream&amp; operator&lt;&lt;(std::ostream&amp; o, number&a=
mp;){ return o; }<br>
=A0 =A0 =A0int main(){<br>
=A0 =A0 =A0 =A0 =A0lua_State* L =3D NULL;<br>
=A0 =A0 =A0 =A0 =A0using namespace luabind;<br>
module(L)[class_&lt;number&gt;(&quot;number&quot;).def(tostring(self))];<br=
>
=A0 =A0 =A0}<br>
<br>
It compiles only if you put use this signature for &lt;&lt;:<br>
<br>
std::ostream&amp; operator&lt;&lt;(std::ostream&amp; out, const A&amp;)<br>
<br>
Also, I would expect that const_self is required in the def, but it<br>
seems that it doesn&#39;t matter. Is this intended behaviour or a bug?<br>
<br>
Cheers.<br>
<br>
---------------------------------------------------------------------------=
---<br>
Precog is a next-generation analytics platform capable of advanced<br>
analytics on semi-structured data. The platform includes APIs for building<=
br>
apps and a phenomenal toolset for data science. Developers can use<br>
our toolset for easy data analysis &amp; visualization. Get a free account!=
<br>
<a href=3D"http://www2.precog.com/precogplatform/slashdotnewsletter" target=
=3D"_blank">http://www2.precog.com/precogplatform/slashdotnewsletter</a><br=
>
_______________________________________________<br>
luabind-user mailing list<br>
<a href=3D"mailto:[email protected]">[email protected]=
urceforge.net</a><br>
<a href=3D"https://lists.sourceforge.net/lists/listinfo/luabind-user" targe=
t=3D"_blank">https://lists.sourceforge.net/lists/listinfo/luabind-user</a><=
br>
</blockquote></div><br><br clear=3D"all"><div><br></div>-- <br>Szymon Gatne=
r<br>The Lordz Games Studio<br><a href=3D"http://www.thelordzgamesstudio.co=
m" target=3D"_blank">www.thelordzgamesstudio.com</a>
</div>

--047d7b5dbbe4fb7b4504da9ddcf5--


--===============7973288051008614511==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

------------------------------------------------------------------------------
Precog is a next-generation analytics platform capable of advanced
analytics on semi-structured data. The platform includes APIs for building
apps and a phenomenal toolset for data science. Developers can use
our toolset for easy data analysis & visualization. Get a free account!
http://www2.precog.com/precogplatform/slashdotnewsletter
--===============7973288051008614511==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
luabind-user mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/luabind-user

--===============7973288051008614511==--