ginac: Test using example

Build and run an example program from the ginac documentation.

pkgs/by-name/gi/ginac/ginac-example-test.nix

@@ -0,0 +1,36 @@
+{
+  runCommand,
+  gccStdenv,
+  cln,
+  ginac,
+}:
+runCommand "ginac-example-test"
+  {
+    nativeBuildInputs = [
+      gccStdenv.cc
+      ginac
+      cln
+    ];
+  }
+  ''
+    echo "
+      #include <iostream>
+      #include <ginac/ginac.h>
+      using namespace std;
+      using namespace GiNaC;
+
+      int main() {
+        symbol x(\"x\"), y(\"y\");
+        ex poly;
+
+        for (int i=0; i<3; ++i) {
+          poly += factorial(i+16)*pow(x,i)*pow(y,2-i);
+        }
+
+        cout << poly << endl;
+        return 0;
+      }" > hello.cc
+    c++ -lginac -lcln hello.cc -o hello
+    ./hello
+    mkdir $out
+  ''

pkgs/by-name/gi/ginac/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   gccStdenv,
+  callPackage,
   fetchurl,
   cln,
   pkg-config,
@@ -36,6 +37,8 @@ gccStdenv.mkDerivation (finalAttrs: {
 
   configureFlags = [ "--disable-rpath" ];
 
+  passthru.tests.example = callPackage ./ginac-example-test.nix { ginac = finalAttrs.finalPackage; };
+
   meta = {
     description = "GiNaC C++ library for symbolic manipulations";
     homepage = "https://www.ginac.de/";