Even friendlier conftab::add thanks to non-deducible template parameters

Now, no casts at all should be needed. See the Stack Overflow link in
weak_template.h for details. This'll probably be useful elsewhere too.

Author: s4y

async/Makefile.am

@@ -29,7 +29,7 @@ parseopt.h qhash.h refcnt.h rxx.h serial.h stllike.h str.h	\
 suio++.h sysconf.h union.h vatmpl.h vec.h rwfd.h litetime.h       	\
 corebench.h qtailq.h sfs_select.h rclist.h dynenum.h         \
 rctailq.h rctree.h sfs_bundle.h alog2.h sfs_profiler.h wide_str.h 	\
-sfs_const.h
+sfs_const.h weak_template.h
 
 #
 # begin sfslite changes

async/parseopt.h

@@ -29,6 +29,7 @@
 #include "str.h"
 #include "ihash.h"
 #include "amisc.h"
+#include "weak_template.h"
 
 class parseargs {
 
@@ -262,13 +263,14 @@ class conftab {
   bool run (const str &file, u_int opts = 0, int fd = -1,
             status_t *sp = NULL);
 
-  template<class P, class D>
-  conftab &add (const str &nm, P *dp, D lb, D ub)
-  { return insert (New conftab_int<P> (nm, dp, lb, ub)); }
+  template<typename T>
+  conftab &add (const str &nm, T *dp, WEAK_TMPL(T) lb, WEAK_TMPL(T) ub)
+  { return insert (New conftab_int<T> (nm, dp, lb, ub)); }
 
-  template<class P, class D>
-  conftab &add (const str &nm, P *dp, D lb, D ub, D def)
-  { return insert (New conftab_int<P> (nm, dp, lb, ub, def)); }
+  template<typename T>
+  conftab &add (const str &nm, T *dp,
+    WEAK_TMPL(T) lb, WEAK_TMPL(T) ub, WEAK_TMPL(T) def
+  ) { return insert (New conftab_int<T> (nm, dp, lb, ub, def)); }
 
   template<class A>
   conftab &add (const str &nm, A a)

async/weak_template.h

@@ -0,0 +1,6 @@
+// -*-c++-*-
+#pragma once
+
+// Thanks to Ben Voigt: http://stackoverflow.com/a/17433263/84745
+template <typename T> struct Identity { typedef T type; };
+#define WEAK_TMPL(T) typename Identity<T>::type

dist/freebsd-port/sfslite/pkg-plist

@@ -135,6 +135,7 @@ include/sfslite-%%VERSION%%/%%TAG%%/rabin_fprint.h
 include/sfslite-%%VERSION%%/%%TAG%%/rabinpoly.h
 include/sfslite-%%VERSION%%/%%TAG%%/rexcommon.h
 include/sfslite-%%VERSION%%/%%TAG%%/sfssesscrypt.h
+include/sfslite-%%VERSION%%/%%TAG%%/weak_template.h
 lib/sfslite
 lib/sfslite-%%VERSION%%/acsfs.m4
 lib/sfslite-%%VERSION%%/%%TAG%%/aiod

dist/openbsd-port/pkg/PLIST

@@ -125,6 +125,7 @@ include/sfslite-${REV}/shared/wmstr.h
 include/sfslite-${REV}/shared/xdr_suio.h
 include/sfslite-${REV}/shared/xdrmisc.h
 include/sfslite-${REV}/shared/xhinfo.h
+include/sfslite-${REV}/shared/weak_template.h
 lib/sfslite
 lib/sfslite-${REV}/acsfs.m4
 lib/sfslite-${REV}/shared/aiod