client almost builds

vendor/cryptopp/TestPrograms/test_cxx11_constexpr.cpp

@@ -0,0 +1,10 @@
+constexpr int fact(int n)
+{
+    return n <= 1 ? 1 : (n * fact(n - 1));
+}
+
+int main(int argc, char* argv[])
+{
+    fact(4);
+    return 0;
+}