Library: extract type rebinding helper

...turns out this is entirely generic and not tied to the context
within ActivityDetector, where it was first introduced to build a
mock functor to log all invocations.

Basically this meta-function generates a new instantiation of the
template X, using the variadic argument pack from template U<ARGS...>

src/lib/meta/tuple-helper.hpp

@@ -129,13 +129,13 @@ namespace meta {
   
   /** temporary workaround: match and rebind the type sequence from a tuple */
   template<typename...TYPES>
-  struct RebindTySeq
+  struct RebindTupleTypes
     {
       using Seq  = typename Types<TYPES...>::Seq;
       using List = typename Seq::List;
     };
   template<typename...TYPES>
-  struct RebindTySeq<std::tuple<TYPES...>>
+  struct RebindTupleTypes<std::tuple<TYPES...>>
     {
       using Seq  = typename Types<TYPES...>::Seq;
       using List = typename Seq::List;

src/lib/meta/variadic-helper.hpp

@@ -60,6 +60,7 @@
 namespace lib {
 namespace meta {
   
+   //////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #987 temporary WORKAROUND -- to be obsoleted
   /**
    * temporary workaround:
    * alternative definition of "type sequence",
@@ -117,6 +118,7 @@ namespace meta {
     {
       using Seq = TySeq<>;  // NOTE: this causes the result to be a TySeq
     };
+   //////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #987 temporary WORKAROUND(End) -- to be obsoleted
   
   
   
@@ -144,6 +146,10 @@ namespace meta {
   
   
   
+  
+  /* ==== Build Variadic Sequences ==== **/
+  
+  
   /** Hold a sequence of index numbers as template parameters */
   template<size_t...idx>
   struct IndexSeq
@@ -230,7 +236,7 @@ namespace meta {
   template<typename...TYPES>
   struct BuildIdxIter<Types<TYPES...>>
     {
-      /////TODO as long as Types is not variadic (#987), we need to strip NullType here (instead of just using sizeof...(TYPES)
+      ///////////////////////TICKET #987 : since Types<T...> is not variadic, need to strip NullType here (instead of just using sizeof...(TYPES)
       enum {SIZ = lib::meta::count<typename Types<TYPES...>::List>::value };
       using Builder = BuildIndexSeq<SIZ>;
       
@@ -254,6 +260,34 @@ namespace meta {
   
   
   
+  /* ==== Rebinding Variadic Arguments ==== **/
+  
+  /**
+   * Metaprogramming helper to transfer variadic arguments.
+   * - builds a new type instantiation from the Template \a X
+   * - possibly picks up the variadic argument pack from a given
+   *   source template `U<ARGS....>`
+   * @tparam X a variadic template
+   */
+  template<template<typename...> class X, typename...ARGS>
+  struct RebindVariadic
+    {
+      using Type = X<ARGS...>;
+    };
+  
+  template<template<typename...> class X
+          ,template<typename...> class U
+          ,typename...ARGS>
+  struct RebindVariadic<X, U<ARGS...>>
+    {
+      using Type = X<ARGS...>;
+    };
+  
+  
+  
+  
+  
+  
   
   /* ==== Manipulation of variadic arguments ==== **/
   

src/steam/control/command-simple-closure.hpp

@@ -80,7 +80,7 @@ namespace control {
       using ArgumentBuff = InPlaceBuffer<ArgHolder>;
       
       using ArgTuple = typename ArgHolder::ArgTuple;
-      using Args     = typename lib::meta::RebindTySeq<ArgTuple>::Seq; // std::tuple<ARGS...> to Types<ARGS...>
+      using Args     = typename lib::meta::RebindTupleTypes<ArgTuple>::Seq; // std::tuple<ARGS...> to Types<ARGS...>
       
       
       /* ====== in-place argument storage ====== */

src/steam/control/command-storage-holder.hpp

@@ -86,7 +86,7 @@ namespace control {
       using  MementoBuff = InPlaceBuffer<MemHolder>;
       
       using ArgTuple = typename ArgHolder::ArgTuple;
-      using Args     = typename lib::meta::RebindTySeq<ArgTuple>::Seq; // std::tuple<ARGS...> to Types<ARGS...>
+      using Args     = typename lib::meta::RebindTupleTypes<ArgTuple>::Seq; // std::tuple<ARGS...> to Types<ARGS...>
       
       
       /* ====== in-place storage buffers ====== */

tests/library/meta/tuple-diagnostics.hpp

@@ -80,7 +80,7 @@ namespace test {
   string                >
   showType ()
   {
-    using TypeList = typename RebindTySeq<TUP>::List;
+    using TypeList = typename RebindTupleTypes<TUP>::List;
     using DumpPrinter = InstantiateChained<TypeList, Printer, NullP>;
     
     return "TUPLE"

tests/library/meta/tuple-helper-test.cpp

@@ -117,10 +117,10 @@ namespace test {
       void
       check_tuple_from_Typelist()
         {
-          typedef Types1::List L1; // starting from an existing Typelist...
+          using L1 = Types1::List;          // ... start from existing Typelist...
           
-          typedef Tuple<L1> T_L1;           // derive a tuple type from this typelist
+          using T_L1 = Tuple<L1>;           // derive a tuple type from this typelist
-          typedef RebindTySeq<T_L1>::Seq Seq1;
+          using Seq1 = RebindTupleTypes<T_L1>::Seq;
                                             // extract the underlying type sequence
           DISPLAY (T_L1);
           DISPLAY (Seq1);

tests/vault/gear/activity-detector.hpp

@@ -85,6 +85,7 @@ namespace test {
 //  using lib::time::TimeValue;
 //  using lib::time::Time;
 //  using lib::HashVal;
+  using lib::meta::RebindVariadic;
   using util::isnil;
 //  using util::isSameObject;
 //  using fixture::Segmentation;
@@ -92,22 +93,6 @@ namespace test {
 //  using vault::gear::Job;
 //  using vault::gear::JobClosure;
   
-  namespace {
-    template<template<typename...> class X, typename...ARGS>
-    struct _RebindTypeSeq
-      {
-        using Type = X<ARGS...>;
-      };
-    
-    template<template<typename...> class X
-            ,template<typename...> class U
-            ,typename...ARGS>
-    struct _RebindTypeSeq<X, U<ARGS...>>
-      {
-        using Type = X<ARGS...>;
-      };
-    
-  }
   
   
   /**
@@ -191,7 +176,7 @@ namespace test {
           using Args = typename lib::meta::_Fun<SIG>::Args;
           using ArgsX = typename lib::meta::StripNullType<Args>::Seq;    ////////////////////////////////////TICKET #987 : make lib::meta::Types<TYPES...> variadic
           using SigTypes = typename lib::meta::Prepend<Ret, ArgsX>::Seq;
-          using Functor  = typename _RebindTypeSeq<DiagnosticFun, SigTypes>::Type;
+          using Functor  = typename RebindVariadic<DiagnosticFun, SigTypes>::Type;
           
           return Functor{id, eventLog_};
         }

wiki/thinkPad.ichthyo.mm

@@ -81678,8 +81678,9 @@ Date:&#160;&#160;&#160;Thu Apr 20 18:53:17 2023 +0200<br/>
 <icon BUILTIN="yes"/>
 </node>
 <node CREATED="1690832776060" ID="ID_135731051" MODIFIED="1690832801676" TEXT="X&lt;ARGS...&gt; &#x27fc; U&lt;ARGS...&gt;"/>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1690832821366" ID="ID_958989562" MODIFIED="1690832834253" TEXT="als generisches Util extrahieren">
+<node COLOR="#338800" CREATED="1690832821366" ID="ID_958989562" MODIFIED="1690894004134" TEXT="als generisches Util extrahieren">
-<icon BUILTIN="flag-yellow"/>
+<icon BUILTIN="button_ok"/>
+</node>
 </node>
 </node>
 </node>