\documentclass{article}
\usepackage{pdfpages}
%\VignetteIndexEntry{Using Annoy in C++}
%\VignetteKeywords{Rcpp, Annoy, R, Cpp, Approximate Nearest Neighbours}
%\VignettePackage{RcppAnnoy}

\begin{document}
\includepdf[pages=-, fitpaper=true]{UsingAnnoyInCpp.pdf}
\end{document}