#ifndef STUB
-#include "fatal.h"
-
-#define STUB { fatal(STUB_API " required"); }
-#define STUB_RETVAL(x) { fatal(STUB_API " required"); return x; }
-//#define STUB_RETREF(x) { fatal(STUB_API " required"); x* o = new (x); return *o; }
-// NP: no () around the x here
-#define STUB_RETREF(x) { fatal(STUB_API " required"); return new x; }
-#define STUB_RETSTATREF(x) { fatal(STUB_API " required"); static x v; return v; }
+
+/** \group STUB
+ *
+ * A set of useful macros to create stub_* files.
+ *
+ * Intended for use building unit tests, if a stubbed function is called
+ * by any code it is linked to it will abort with a message indicating
+ * which API file is missing from the linked dependencies.
+ *
+ * Usage:
+ * at the top of your intended stub file define STUB_API to be the
+ * name of the .cc file or library you are providing a stub of
+ * then include this STUB.h header.
+ *
+ * #define STUB_API "foo/libexample.la"
+ * #include "tests/STUB.h"
+ */
+#include <iostream>
+
+// Internal Special: the STUB framework requires this function
+#define stub_fatal(m) { std::cerr<<"FATAL: "<<(m)<<" for use of "<<__FUNCTION__<<"\n"; exit(1); }
+
+/// macro to stub a void function.
+#define STUB { stub_fatal(STUB_API " required"); }
+
+/// macro to stub a void function without a fatal message
+/// Intended for registration pattern APIs where the function result does not matter to the test
+#define STUB_NOP { std::cerr<<"SKIP: "<<STUB_API<<" "<<__FUNCTION__<<" (not implemented).\n"; }
+
+/// macro to stub a function with return value.
+/// Aborts unit tests requiring its definition with a message about the missing linkage
+#define STUB_RETVAL(x) { stub_fatal(STUB_API " required"); return x; }
+
+/// macro to stub a void function without a fatal message and with a return value
+/// Intended for registration pattern APIs where the function result does not matter to the test
+#define STUB_RETVAL_NOP(x) { std::cerr<<"SKIP: "<<STUB_API<<" "<<__FUNCTION__<<" (not implemented).\n"; return x; }
+
+/** macro to stub a function which returns a reference to dynamic
+ * Aborts unit tests requiring its definition with a message about the missing linkage
+ * This macro uses 'new x' to construct a stack vailable for the reference, may leak.
+ * \param x may be the type to define or a constructor call with parameter values
+ */
+#define STUB_RETREF(x) { stub_fatal(STUB_API " required"); return new x; }
+
+/** macro to stub a function which returns a reference to static
+ * Aborts unit tests requiring its definition with a message about the missing linkage
+ * This macro uses static variable definition to avoid leaks.
+ * \param x the type name to define
+ */
+#define STUB_RETSTATREF(x) { stub_fatal(STUB_API " required"); static x v; return v; }
#endif /* STUB */