Use data.data() instead of &data (since it is not obvious that Array is trivially copyable)

test/packetmath.cpp

diff --git a/test/packetmath.cpp b/test/packetmath.cpp
index ba25044..f81c07e 100644
--- a/test/packetmath.cpp
+++ b/test/packetmath.cpp
@@ -44,7 +44,7 @@
   for(Index i = 0; i < data.size(); ++i)
     data[i] = f(a[i], b[i]);
   // Note: The reinterpret_cast works around GCC's class-memaccess warnings:
-  std::memcpy(reinterpret_cast<unsigned char*>(&res), &data, sizeof(T));
+  std::memcpy(reinterpret_cast<unsigned char*>(&res), data.data(), sizeof(T));
   return res;
 }