Utils/Exception: Allow to disable ErrnoExceptions via SENF_NO_ERRNOEXC

[senf.git] / Utils / mpl.hh

diff --git a/Utils/mpl.hh b/Utils/mpl.hh
index bb9115e..5428e1d 100644 (file)
--- a/Utils/mpl.hh
+++ b/Utils/mpl.hh
@@ -36,9 +36,18 @@
 namespace senf {
 namespace mpl {
 
-    /** \defgroup senfmpl Low-level template meta programming helpers
+    /** \defgroup senfmpl Template meta programming helpers
      */
 
+    /** \brief Marker class for empty default values etc.
+
+        This is like Boosts \c boost::mpl::na just an empty class used as template default argument
+        to mark missing arguments 
+        
+        \note Don't use this as an empty base class. We may add some informative members to this.
+     */
+    struct nil {};
+
     /** \brief Return-value type used to implement overload selection
 
         The senf::mpl::rv type is used together with \ref SENF_MPL_RV() to select template
@@ -96,8 +105,8 @@ namespace mpl {
         never called.
 
         This number is than forwarded as template argument to \c select which is specialized for
-        each case. Therefore, <tt>choice<A></tt> has a \c frobble() member whereas
-        <tt>choice<B></tt> has a \c dazzle() member.
+        each case. Therefore, <tt>choice\<A\></tt> has a \c frobble() member whereas
+        <tt>choice\<B\></tt> has a \c dazzle() member.
 
         \see \ref SENF_MPL_RV
         \ingroup senfmpl