Hi Nikhil,
Here's an updated version that exposes a FooWrapper class in the module to
the previous posted code. Hopefully this helps!
class FooWrapper{
public:
Foo* foo_m;
FooWrapper(){}
FooWrapper(const FooWrapper& other):foo_m(other.foo_m){
}
FooWrapper(Foo* foo):foo_m(foo){
}
void SayHello(){
Rcpp::Rcout << "From \"void SayHello()\" -> "<<(this->foo_m)<<" -> ";
Rcpp::Rcout << "hello from Foo.\n";
}
};
RCPP_EXPOSED_CLASS(FooWrapper)
FooWrapper GetSingleton(){
FooWrapper ret(Foo::GetSingleton());
Rcpp::Rcout<<"From \"Foo& GetSingleton()\" -> memory address for
singleton is " <<ret.foo_m<<"\n";
return ret;
}
RCPP_MODULE(foo) {
Rcpp::class_<FooWrapper>("Foo")
.constructor()
.method("SayHello", &FooWrapper::SayHello);
Rcpp::function("GetSingleton", &GetSingleton);
}
On Wed, Feb 21, 2024 at 10:51 AM Matthew Supernaw - NOAA Federal <
matthew.super...@noaa.gov> wrote:
> Looks like I posted too soon. I just noticed the memory address from the
> "SayHello" function doesn't match.
>
> On Wed, Feb 21, 2024 at 10:47 AM Matthew Supernaw - NOAA Federal <
> matthew.super...@noaa.gov> wrote:
>
>> Hi Nikhil,
>> I'm not exactly sure what you are trying to do, but I hope this simple
>> example is helpful.
>> Thanks.
>> Matthew
>>
>>
>> #include <Rcpp.h>
>> using namespace Rcpp;
>>
>>
>> class Foo{
>> public:
>> static Foo* singleton;
>>
>> Foo(){
>> }
>>
>> void SayHello(){
>> Rcpp::Rcout << "From \"void SayHello()\" -> "<<this<<" -> ";
>> Rcpp::Rcout << "hello from Foo.\n";
>> }
>>
>> static Foo* GetSingleton(){
>>
>> if(singleton == NULL){
>> Foo::singleton = new Foo();
>> }
>> Rcpp::Rcout<<"From \"static Foo* GetSingleton()\" -> memory address
>> for singleton is " <<Foo::singleton<<"\n";
>> return Foo::singleton;
>> }
>> };
>>
>> Foo* Foo::singleton = NULL;
>>
>> RCPP_EXPOSED_CLASS(Foo)
>>
>> Foo& GetSingleton(){
>> Foo* foo_singleton = Foo::GetSingleton();
>> Rcpp::Rcout<<"From \"Foo& GetSingleton()\" -> memory address for
>> singleton is " <<foo_singleton<<"\n";
>> return *foo_singleton;
>> }
>>
>> RCPP_MODULE(foo) {
>> Rcpp::class_<Foo>("Foo")
>> .constructor()
>> .method("SayHello", &Foo::SayHello);
>> Rcpp::function("GetSingleton", &GetSingleton);
>>
>> }
>> //From R
>> // library(singleton)
>> // library(Rcpp)
>> //
>> // foo <- Rcpp::Module("foo", PACKAGE = "singleton")
>> //
>> // foo_singleton<-foo$GetSingleton()
>> // foo_singleton$SayHello()
>>
>> // Output:
>> // From "static Foo* GetSingleton()" -> memory address for singleton is
>> 0x7fcdf9387590
>> // From "Foo& GetSingleton()" -> memory address for singleton is
>> 0x7fcdf9387590
>> // From "void SayHello()" -> 0x7fcdf9392b60 -> hello from Foo.
>>
>> On Wed, Feb 21, 2024 at 1:34 AM Nikhil Garg <nikhilgarg....@gmail.com>
>> wrote:
>>
>>> Hi,
>>>
>>> I am looking for some advice or hoping someone can point me in the right
>>> direction for wrapping a C++ class with singleton using Rcpp. I have been
>>> using RCPP modules for some of this work but got stuck with a C++ object
>>> which returns a singleton.
>>>
>>> Here is the general structure of the object
>>>
>>> class Foo {
>>> public:
>>> Foo();
>>> ~Foo();
>>>
>>> static Foo &getFoo();
>>> Foo(Foo const&) = delete;
>>> void operator=(Foo const&) = delete;
>>> }
>>>
>>> Regards,
>>> Nikhil
>>> _______________________________________________
>>> Rcpp-devel mailing list
>>> Rcpp-devel@lists.r-forge.r-project.org
>>> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
>>>
>>
>>
>> --
>> Matthew Supernaw
>> *Scientific Software Developer*
>> *National Oceanic and Atmospheric Administration*
>> *Office Of Science and Technology*
>> *NOAA Fisheries | *U.S. Department of Commerce
>> Phone 248 - 396 - 7797
>>
>>
>>
>
> --
> Matthew Supernaw
> *Scientific Software Developer*
> *National Oceanic and Atmospheric Administration*
> *Office Of Science and Technology*
> *NOAA Fisheries | *U.S. Department of Commerce
> Phone 248 - 396 - 7797
>
>
>
--
Matthew Supernaw
*Scientific Software Developer*
*National Oceanic and Atmospheric Administration*
*Office Of Science and Technology*
*NOAA Fisheries | *U.S. Department of Commerce
Phone 248 - 396 - 7797
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