[R-pkg-devel] Virtual C++ functions

[Serguei Sokol]

Le 15/11/2023 à 10:37, Michael Meyer via R-package-devel a écrit :
> Greetings,
> Suppose I wanted to develop a package with C++ code that contains virtual functions which the package user should define.It's assumed that evaluation is expensive so we do not want to define these in R and then call these R-functions from C++.
Hm, virtual C++ functions are defined at compilation time. Their binding 
is done at runtime but at compilation time they must be already defined. 
So, how a package user (who already installed and therefor compiled your 
package) could define them? Moreover in R?
Or may be you mean that a user import your C++ code and define his own 
derived function based on your virtual functions in his C++ code?
Or, another option, you call "virtual function" what is usually called 
"callback function" like e.g. a function searching for roots of any user 
defined function and taking it as a parameter. This latter is a callback 
function.

Could you precise what you mean by "virtual function" and "package user 
should define"?

Best,
Serguei.

> Is this a reasonable idea with a standard solution?Are there packages that do this?
> Thanks in advance for all answers,
> 
> Michael Meyer
> 	[[alternative HTML version deleted]]
> 
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