On 12 August 2011 at 14:50, Chris DuBois wrote:
| Hi all,
|
| I'm trying to figure out how to pass in an array of integers to a function
| inside a module. For example, adding the following function to runit.Module.R
| works fine:
|
| int bla3( IntegerVector x ) {
| return sum(x);
| }
|
| However, I need to pass an int array, rather than an IntegerVector. Using int
| x[] in the arguments doesn't compile (though I'm unfamiliar with C++ in
| general, so maybe this shouldn't work anyway).
|
| Alternatively, should I just cast x from an IntegerVector to an int array? I
| tried various permutations of as, vector, <int>, etc, and would like to learn
| the proper way of doing this.
You generally do not want old school x[] arrays in C++. Why? Because STL
vectors do _everything_ they do at (essentially) zero added cost, free you
from malloc/free and still allow you to access the straight memory should you
need to (to talk to a C API, say).
So use IntegerVector for _the interface_. You can the, if you must, do
IntegerVector x;
int a1[] = x.begin(); // STL-style iterator to beginning of memory
int *a2 = x.begin(); // idem
Hope this helps, Dirk
--
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