Fixing ambiguous arithmetic operators for Matrix/Vector on 32-bit

[dcdillon]

So the crux of this is it makes templates that match exactly the function calls that happened. I achieved this by adding another template parameter to each of the arithmetic operators for for Vector and Matrix and then restricting the values allowed for this template parameter using enable_if.

Additionally, the same ambiguities can be exposed with the following C++ code on 64-bit (though it's unlikely anyone would have done this):

#include <Rcpp.h>

void testFunction(Rcpp::NumericVector x, long l)
{
        Rcpp::NumericVector y = x + l;
}

void testFunction2(Rcpp::NumericMatrix x, long l)
{
        Rcpp::NumericMatrix y = x + l;
}

@eddelbuettel, @kevinushey, @thirdwing please have a look.

[dcdillon]

Hmm...perhaps it should be traits::is_convertible<T, typename traits::storage_type<RTYPE>::type> instead of traits::is_primitive.

Will do that if people agree.

[thirdwing]

Just confirmed this fixed 64-bit and 32-bit situations.

Let's merge this if it doesn't break any other packages.

[eddelbuettel]

We just got Rcpp 0.12.5 onto CRAN so we have a moment -- but yes, will rev.dep this.

[eddelbuettel]

With the various 'LGTM' having come in I'll just merge, turn on a rev.dep run -- and have the option to revert later today should it be necessary.