require( inline )

require( Rcpp )

expressions <- list(

times = "x * y" ,

plus = "x + y"

# ,

# minus = "x - y",

# divides = "x / y",

# exp_ = "exp( x )"

)

signatures <- lapply( expressions, function(.) signature( x_ = "numeric", y_ = "numeric", n_ = "integer" ) )

bodies <- lapply( expressions, function(.){

sprintf( '

int n = as<int>( n_ ) ;

NumericVector x(x_), y(y_), z(x.size()) ;

for( int i=0; i<n; i++){

z = %s ;

}

return z ;

', . )

} )

fx <- cxxfunction( signatures, bodies, plugin = "Rcpp" )

set.seed( 43231 )

x <- runif( 100000, min = 1, max = 100)

y <- runif( 100000, min = 1, max = 100)

# resolving the dyn lib once

invisible( lapply( fx, function(f){ f( x, y, 1L) } ) )

# t( sapply( fx, function(f){

# system.time( f( x, y, 10000 ) )

# } ) )[, 1:3]

#