1 files changed, 14 insertions, 0 deletions
diff --git a/test/mkmf/test_egrep_cpp.rb b/test/mkmf/test_egrep_cpp.rb
index 7ac0e60010..1126324965 100644
--- a/test/mkmf/test_egrep_cpp.rb
+++ b/test/mkmf/test_egrep_cpp.rb
@@ -10,4 +10,18 @@ class TestMkmfEgrepCpp < TestMkmf
   def test_not_have_func
     assert_equal(false, egrep_cpp(/never match/, ""), MKMFLOG)
   end
+
+  class TestMkmfEgrepCxx < self
+    def test_cxx_egrep_cpp
+      assert_equal(true, MakeMakefile["C++"].egrep_cpp(/^ok/, <<~SRC), MKMFLOG)
+      #ifdef __cplusplus
+      ok
+      #else
+      #error not C++
+      #endif
+      SRC
+    rescue Errno::ENOENT
+      omit "C++ compiler not available: #{$!.message}"
+    end
+  end
 end