[Rcpp-devel] long long

[Romain Francois]

Le 19/09/13 17:39, Dirk Eddelbuettel a écrit :
>
> On 19 September 2013 at 15:48, Romain Francois wrote:
> | What I want is to change this:
> |
> | #if defined(__GNUC__)
> | #if defined(__GXX_EXPERIMENTAL_CXX0X__) || (defined (__clang__) &&
> | defined(__LP64__))
> | #ifdef __LONG_LONG_MAX__
> |      __extension__ typedef long long int rcpp_long_long_type;
> |      __extension__ typedef unsigned long long int rcpp_ulong_long_type;
> |      #define RCPP_HAS_LONG_LONG_TYPES
> | #endif
> | #endif
> | #endif
> |
> |
> | to this:
> |
> | #if defined(__GNUC__) &&  defined(__LONG_LONG_MAX__)
> |      __extension__ typedef long long int rcpp_long_long_type;
> |      __extension__ typedef unsigned long long int rcpp_ulong_long_type;
> |      #define RCPP_HAS_LONG_LONG_TYPES
> | #endif
>
> That's novel and could work.  May need testing.  May also need to be checked
> against just using -std=c++11 / -std=c++0x which give us long long rightaway.

That just works. This is just a typedef.

> Also note that Murray got a similar trick into RProtoBuf, albeit at the cost
> of configure test (by finding an M4 macros which determines whether the
> compiler can in fact do c++11, and if so, turns it on).

Might not be cran proof right. Last time I checked, we were not allowed 
to use std=c++11 which is the gcc way of using C++ 11.

We don't need C++ 11 for long long, we just need a compiler that 
supports long long in a way that does not upset cran.

> | And as long as we don't actually have "long long" in code, but use
> | "rcpp_long_long_type" then we are fine :
>
> What happens when you have 'long long' via C++11? Do they coexist?

Of course. This is is the same type. __extension__ is just a way to tell 
-pedantic to STFU about it.

> Also not sure why you first post which seemingly asks for comments and then
> still rush to commit before anyone has comments.  Oh well.

You are running the Dirk compiler with the -pedantic option right ?

I've put it in because I believe it is fine, I have tested on 2 systems.

It does not mean however that I'm not welcoming comments. In particular, 
I've sent a private mail to Murray asking for his thoughts.

At least, being in it has more chances to be tested.

-- 
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30