From 7e766f848d4f075fce815711b201d983aa8989dd Mon Sep 17 00:00:00 2001
From: nojhan <nojhan@nojhan.net>
Date: Sun, 22 Mar 2020 18:57:50 +0100
Subject: [PATCH] add eoStoreFunctor::pack to allocate & store in one line

Instead of calling `new`, then `state.storeFunctor`, the user can just call
`Class& inst = state.pack< Class >( params )` in one line.

Use C++11's variadic templates.
---
 eo/src/eoFunctorStore.h | 40 ++++++++++++++++++++++++++++------------
 1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/eo/src/eoFunctorStore.h b/eo/src/eoFunctorStore.h
index ffcbe90d7..889b832de 100644
--- a/eo/src/eoFunctorStore.h
+++ b/eo/src/eoFunctorStore.h
@@ -54,20 +54,36 @@ public:
     /// Add an eoFunctorBase to the store
     template <class Functor>
     Functor& storeFunctor(Functor* r)
-        {
+    {
 #ifndef NDEBUG
-        unsigned int existing = std::count( vec.begin(), vec.end(), r );
-        if( existing > 0 ) {
-             eo::log << eo::warnings << "WARNING: you asked eoFunctorStore to store the functor " << r << " " 
-                     << existing + 1 << " times, a segmentation fault may occur in the destructor." << std::endl;
-        }
+    unsigned int existing = std::count( vec.begin(), vec.end(), r );
+    if( existing > 0 ) {
+         eo::log << eo::warnings << "WARNING: you asked eoFunctorStore to store the functor " << r << " " 
+                 << existing + 1 << " times, a segmentation fault may occur in the destructor." << std::endl;
+    }
 #endif
-            // If the compiler complains about the following line,
-            // check if you really are giving it a pointer to an
-            // eoFunctorBase derived object
-            vec.push_back(r);
-            return *r;
-        }
+        // If the compiler complains about the following line,
+        // check if you really are giving it a pointer to an
+        // eoFunctorBase derived object
+        vec.push_back(r);
+        return *r;
+    }
+
+    /** Allocate the given functor, store it and return its reference.
+     *
+     * Indicate the class to instanciate as template paramater,
+     * and pass its constructor arguments.
+     *
+     * @code
+     * eoSelect<EOT>& selector = state.pack< eoRankMuSelect<EOT> >( mu );
+     * @endcode
+     */
+    template<class Functor, class... Args>
+    Functor& pack( Args&&... args )
+    {
+        Functor* f = new Functor(args...);
+        return this->storeFunctor(f);
+    }
 
 private :