Conditional C++ chunks if linking against rTRNG works.

* New exported function `try`ing a minimal `sourceCpp()`.
* Should fix macOS check issues (re)building the vignettes (#10).

NAMESPACE

@@ -7,6 +7,7 @@ export(TRNGjump)
 export(TRNGkind)
 export(TRNGseed)
 export(TRNGsplit)
+export(check_rTRNG_linking)
 export(defaultKind)
 export(lagfib2plus_19937_64)
 export(lagfib2xor_19937_64)

R/LdFlags.R

@@ -56,3 +56,34 @@ asBuildPath <- function(path) {
   }
   return(path)
 }
+
+sourceCpp_minimal_code <- '
+// [[Rcpp::depends(rTRNG)]]
+// [[Rcpp::plugins(cpp11)]]
+#include <Rcpp.h>
+#include <trng/yarn2.hpp>
+// [[Rcpp::export]]
+void exampleCpp() {
+  trng::yarn2 rng;
+}
+'
+
+#' Check rTRNG linking.
+#'
+#' Check whether C++ code using the TRNG library can be built and linked against
+#' \pkg{rTRNG} on the current system.
+#'
+#' @inheritParams base::try
+#'
+#' @return A scalar logical with the result of the check. If \code{FALSE}, using
+#'   the TRNG library from C++ code sourced via \code{\link[Rcpp]{sourceCpp}} or
+#'   part of an \R package is not expected to work.
+#'
+#' @export
+check_rTRNG_linking <- function(silent = FALSE) {
+  check <- try(
+    silent = silent,
+    Rcpp::sourceCpp(code = sourceCpp_minimal_code)
+  )
+  !inherits(check, "try-error")
+}

vignettes/mcMat.Rmd

@@ -13,16 +13,19 @@ vignette: >
 ```{r setup, include=FALSE}
 knitr::opts_chunk$set(collapse = TRUE)
 options(digits = 5) # for kable
+linking_ok <- rTRNG::check_rTRNG_linking()
 ```
 
 
 ```{r include=FALSE, cache=FALSE}
 source("utils/read_chunk_wrap.R", echo = FALSE, print.eval = FALSE)
 read_chunk_wrap("code/mcMat.R")
-Rcpp::sourceCpp("code/mcMat.cpp", verbose = FALSE, embeddedR = FALSE)
 read_chunk_wrap("code/mcMat.cpp")
-Rcpp::sourceCpp("code/mcMatParallel.cpp", verbose = FALSE, embeddedR = FALSE)
 read_chunk_wrap("code/mcMatParallel.cpp")
+if (linking_ok) {
+  Rcpp::sourceCpp("code/mcMat.cpp", verbose = FALSE, embeddedR = FALSE)
+  Rcpp::sourceCpp("code/mcMatParallel.cpp", verbose = FALSE, embeddedR = FALSE)
+}
 ```
 
 Consider the Monte Carlo simulation of a matrix of i.i.d. normal random
@@ -71,9 +74,9 @@ enforces the C++11 standard required by TRNG >= 4.22.
 ```
 As seen above for the R case, consistency of the simulation obtained via
 `mcSubMatRcpp` with the full sequential simulation is guaranteed.
-```{r subMatExampleRcpp}
+```{r subMatExampleRcpp, eval=linking_ok}
 ```
-```{r, echo=FALSE}
+```{r, echo=FALSE, eval=linking_ok}
 knitr::kable(cbind.data.frame(M = M, S = S), row.names = TRUE)
 ```
 
@@ -88,12 +91,12 @@ Monte Carlo simulations in parallel, for any subset `subCols` of the variables.
 ```
 The parallel nature of the `yarn2` generator ensures the parallel simulation is
 playing fair, i.e. is consistent with the sequential simulation.
-```{r fullMatExampleRcppParallel}
+```{r fullMatExampleRcppParallel, eval=linking_ok}
 ```
 Similarly, we can achieve a consistent parallel simulation of a subset of the
 variables only.
-```{r subMatExampleRcppParallel}
+```{r subMatExampleRcppParallel, eval=linking_ok}
 ```
-```{r, echo=FALSE}
+```{r, echo=FALSE, eval=linking_ok}
 knitr::kable(cbind.data.frame(M = M, Sp = Sp), row.names = TRUE)
 ```

vignettes/rTRNG.Rmd

@@ -12,6 +12,7 @@ vignette: >
 
 ```{r setup, include=FALSE}
 knitr::opts_chunk$set(echo = TRUE, collapse = TRUE)
+linking_ok <- rTRNG::check_rTRNG_linking()
 ```
 
 
@@ -105,7 +106,7 @@ easily be compiled, specifying the `Rcpp::depends` attribute that allows
 `Rcpp::plugins(cpp11)` is needed to enforce the C++11 standard required by TRNG
 >= 4.22.
 
-```{Rcpp sourceCpp}
+```{Rcpp sourceCpp, eval=linking_ok}
 // [[Rcpp::depends(rTRNG)]]
 // TRNG >= 4.22 requires C++11
 // [[Rcpp::plugins(cpp11)]]
@@ -132,7 +133,7 @@ NumericVector exampleCpp() {
 exampleCpp()
 */
 ```
-```{r sourceCpp-R, echo=FALSE}
+```{r sourceCpp-R, echo=FALSE, eval=linking_ok}
 exampleCpp()
 ```