New type safe visitor framework

8 files changed, 164 insertions, 100 deletions

diff --git a/paludis/args/args_dumper.cc b/paludis/args/args_dumper.cc
index 5c0e0ac87..66f9e5027 100644
--- a/paludis/args/args_dumper.cc
+++ b/paludis/args/args_dumper.cc
@@ -19,6 +19,7 @@
 
 #include <paludis/args/args_dumper.hh>
 #include <paludis/args/args_option.hh>
+#include <paludis/util/visitor-impl.hh>
 
 #include <sstream>
 
@@ -36,34 +37,26 @@ ArgsDumper::ArgsDumper(std::ostream & os) :
 {
 }
 
-void ArgsDumper::visit(const ArgsOption * const a)
+void ArgsDumper::generic_visit(const ArgsOption & a)
 {
     std::stringstream p;
-    p << "  --" << a->long_name();
-    if (a->short_name())
-        p << ", -" << a->short_name();
+    p << "  --" << a.long_name();
+    if (a.short_name())
+        p << ", -" << a.short_name();
     if (p.str().length() < 24)
         p << std::string(24 - p.str().length(), ' ');
     else
         p << std::endl << std::string(24, ' ');
     _os << p.str();
-    _os << " " << a->description() << std::endl;
+    _os << " " << a.description() << std::endl;
 }
 
-#define VISIT(type) void ArgsDumper::visit(const type * const a) \
-    { visit(static_cast<const ArgsOption *>(a)); }
-
-VISIT(SwitchArg)
-VISIT(StringArg)
-VISIT(IntegerArg)
-VISIT(AliasArg)
-
-void ArgsDumper::visit(const StringSetArg * const a)
+void ArgsDumper::visit(const StringSetArg & a)
 {
-    visit(static_cast<const ArgsOption *>(a));
+    generic_visit(a);
 
-    if (a->begin_allowed_args() != a->end_allowed_args())
-        for (StringSetArg::AllowedArgIterator it = a->begin_allowed_args(), it_end = a->end_allowed_args();
+    if (a.begin_allowed_args() != a.end_allowed_args())
+        for (StringSetArg::AllowedArgIterator it = a.begin_allowed_args(), it_end = a.end_allowed_args();
                 it != it_end; ++it)
         {
             std::stringstream p;
@@ -76,10 +69,11 @@ void ArgsDumper::visit(const StringSetArg * const a)
         }
 }
 
-void ArgsDumper::visit(const EnumArg * const a)
+void ArgsDumper::visit(const EnumArg & a)
 {
-    visit(static_cast<const ArgsOption *>(a));
-    for (EnumArg::AllowedArgIterator it = a->begin_allowed_args(), it_end = a->end_allowed_args();
+    generic_visit(a);
+
+    for (EnumArg::AllowedArgIterator it = a.begin_allowed_args(), it_end = a.end_allowed_args();
             it != it_end; ++it)
     {
         std::stringstream p;
@@ -88,8 +82,33 @@ void ArgsDumper::visit(const EnumArg * const a)
             p << std::string(26 - p.str().length(), ' ');
         _os << p.str();
         _os << " " << (*it).second;
-        if ((*it).first == a->default_arg())
+        if ((*it).first == a.default_arg())
             _os << " (default)";
         _os << std::endl;
     }
 }
+
+void
+ArgsDumper::visit(const SwitchArg & a)
+{
+    generic_visit(a);
+}
+
+void
+ArgsDumper::visit(const StringArg & a)
+{
+    generic_visit(a);
+}
+
+void
+ArgsDumper::visit(const IntegerArg & a)
+{
+    generic_visit(a);
+}
+
+void
+ArgsDumper::visit(const AliasArg & a)
+{
+    generic_visit(a);
+}
+
diff --git a/paludis/args/args_dumper.hh b/paludis/args/args_dumper.hh
index c1cd9c151..c0fa70ef5 100644
--- a/paludis/args/args_dumper.hh
+++ b/paludis/args/args_dumper.hh
@@ -41,37 +41,36 @@ namespace paludis
          * \ingroup grplibpaludisargs
          */
         class PALUDIS_VISIBLE ArgsDumper :
-            public ArgsVisitorTypes::ConstVisitor
+            public ConstVisitor<ArgsVisitorTypes>
         {
             private:
                 std::ostream & _os;
 
+                void generic_visit(const ArgsOption &);
+
             public:
                 /**
                  * Constructor.
                  */
                 ArgsDumper(std::ostream & os);
 
-                /// Visit an ArgsOption.
-                void visit(const ArgsOption * const);
-
                 /// Visit a SwitchArg.
-                void visit(const SwitchArg * const);
+                void visit(const SwitchArg &);
 
                 /// Visit a StringArg.
-                void visit(const StringArg * const);
+                void visit(const StringArg &);
 
                 /// Visit an IntegerArg.
-                void visit(const IntegerArg * const);
+                void visit(const IntegerArg &);
 
                 /// Visit an AliasArg.
-                void visit(const AliasArg * const);
+                void visit(const AliasArg &);
 
                 /// Visit an EnumArg.
-                void visit(const EnumArg * const);
+                void visit(const EnumArg &);
 
                 /// Visit a StringSetArg.
-                void visit(const StringSetArg * const);
+                void visit(const StringSetArg &);
         };
     }
 }
diff --git a/paludis/args/args_handler.cc b/paludis/args/args_handler.cc
index f1287c127..341154bd8 100644
--- a/paludis/args/args_handler.cc
+++ b/paludis/args/args_handler.cc
@@ -21,6 +21,8 @@
 #include "args_dumper.hh"
 #include <paludis/util/system.hh>
 #include <paludis/util/join.hh>
+#include <paludis/util/iterator.hh>
+#include <paludis/util/visitor-impl.hh>
 #include <algorithm>
 #include <sstream>
 #include <list>
@@ -133,7 +135,7 @@ ArgsHandler::run(const int argc, const char * const * const argv,
             std::map<std::string, ArgsOption *>::iterator it = _imp->longopts.find(arg);
             if (it == _imp->longopts.end())
                 throw BadArgument("--" + arg);
-            (*it).second->accept(&visitor);
+            it->second->accept(visitor);
         }
         else if (arg[0] == '-')
         {
@@ -145,7 +147,7 @@ ArgsHandler::run(const int argc, const char * const * const argv,
                 {
                     throw BadArgument(std::string("-") + *c);
                 }
-                (*it).second->accept(&visitor);
+                it->second->accept(visitor);
             }
         }
         else
@@ -171,7 +173,7 @@ ArgsHandler::dump_to_stream(std::ostream & s) const
     {
         s << (*g)->name() << ":" << std::endl;
 
-        std::for_each((*g)->begin(), (*g)->end(), accept_visitor(&dump));
+        std::for_each(indirect_iterator((*g)->begin()), indirect_iterator((*g)->end()), accept_visitor(dump));
 
         s << std::endl;
     }
diff --git a/paludis/args/args_option.cc b/paludis/args/args_option.cc
index 6731f7407..9013499b6 100644
--- a/paludis/args/args_option.cc
+++ b/paludis/args/args_option.cc
@@ -29,6 +29,7 @@
  * \ingroup grplibpaludisargs
  */
 
+using namespace paludis;
 using namespace paludis::args;
 
 namespace
diff --git a/paludis/args/args_option.hh b/paludis/args/args_option.hh
index f6a3a3532..d091bdba4 100644
--- a/paludis/args/args_option.hh
+++ b/paludis/args/args_option.hh
@@ -42,7 +42,7 @@ namespace paludis
          * \ingroup grplibpaludisargs
          */
         class PALUDIS_VISIBLE ArgsOption :
-            public virtual VisitableInterface<ArgsVisitorTypes>
+            public virtual MutableAcceptInterface<ArgsVisitorTypes>
         {
             friend class ArgsHandler;
 
@@ -68,7 +68,7 @@ namespace paludis
                 /**
                  * Destructor.
                  */
-                ~ArgsOption();
+                virtual ~ArgsOption();
 
             public:
                 /**
@@ -129,7 +129,7 @@ namespace paludis
          */
         class PALUDIS_VISIBLE SwitchArg :
             public ArgsOption,
-            public Visitable<SwitchArg, ArgsVisitorTypes>
+            public MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, SwitchArg>
         {
             public:
                 /**
@@ -148,7 +148,7 @@ namespace paludis
          */
         class PALUDIS_VISIBLE StringArg :
             public ArgsOption,
-            public Visitable<StringArg, ArgsVisitorTypes>
+            public MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, StringArg>
         {
             private:
                 std::string _argument;
@@ -187,7 +187,7 @@ namespace paludis
          */
         class PALUDIS_VISIBLE StringSetArg :
             public ArgsOption,
-            public Visitable<StringSetArg, ArgsVisitorTypes>,
+            public MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, StringSetArg>,
             private PrivateImplementationPattern<StringSetArg>
         {
             private:
@@ -285,7 +285,7 @@ namespace paludis
          */
         class PALUDIS_VISIBLE AliasArg :
             public ArgsOption,
-            public Visitable<AliasArg, ArgsVisitorTypes>
+            public MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, AliasArg>
         {
             private:
                 ArgsOption * const _other;
@@ -322,7 +322,7 @@ namespace paludis
          */
         class PALUDIS_VISIBLE IntegerArg :
             public ArgsOption,
-            public Visitable<IntegerArg, ArgsVisitorTypes>
+            public MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, IntegerArg>
         {
             private:
                 int _argument;
@@ -352,7 +352,7 @@ namespace paludis
          */
         class PALUDIS_VISIBLE EnumArg :
             public ArgsOption,
-            public Visitable<EnumArg, ArgsVisitorTypes>,
+            public MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, EnumArg>,
             private PrivateImplementationPattern<EnumArg>
         {
             private:
@@ -360,7 +360,6 @@ namespace paludis
                 const std::string _default_arg;
 
             public:
-
                 /**
                  * Helper class for passing available options and associated descriptions
                  * to the EnumArg constructor.
diff --git a/paludis/args/args_visitor.cc b/paludis/args/args_visitor.cc
index 4eb20a418..37066ad6b 100644
--- a/paludis/args/args_visitor.cc
+++ b/paludis/args/args_visitor.cc
@@ -20,6 +20,7 @@
 #include "args_error.hh"
 
 #include <paludis/util/visitor.hh>
+#include <paludis/util/visitor-impl.hh>
 #include <paludis/util/destringify.hh>
 #include <paludis/util/system.hh>
 #include <paludis/util/join.hh>
@@ -35,7 +36,31 @@
  */
 
 using namespace paludis;
-using namespace args;
+using namespace paludis::args;
+
+template class MutableVisitor<ArgsVisitorTypes>;
+template class MutableAcceptInterface<ArgsVisitorTypes>;
+
+template class MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, IntegerArg>;
+template class MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, EnumArg>;
+template class MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, StringArg>;
+template class MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, StringSetArg>;
+template class MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, AliasArg>;
+template class MutableAcceptInterfaceVisitsThis<ArgsVisitorTypes, SwitchArg>;
+
+template class Visits<IntegerArg>;
+template class Visits<EnumArg>;
+template class Visits<StringArg>;
+template class Visits<StringSetArg>;
+template class Visits<AliasArg>;
+template class Visits<SwitchArg>;
+
+template class Visits<const IntegerArg>;
+template class Visits<const EnumArg>;
+template class Visits<const StringArg>;
+template class Visits<const StringSetArg>;
+template class Visits<const AliasArg>;
+template class Visits<const SwitchArg>;
 
 ArgsVisitor::ArgsVisitor(libwrapiter::ForwardIterator<ArgsVisitor, std::string> * ai,
         libwrapiter::ForwardIterator<ArgsVisitor, std::string> ae,
@@ -47,79 +72,90 @@ ArgsVisitor::ArgsVisitor(libwrapiter::ForwardIterator<ArgsVisitor, std::string>
 }
 
 const std::string &
-ArgsVisitor::get_param(const ArgsOption * const arg)
+ArgsVisitor::get_param(const ArgsOption & arg)
 {
     if (++(*_args_index) == _args_end)
-        throw MissingValue("--" + arg->long_name());
+        throw MissingValue("--" + arg.long_name());
 
     return **_args_index;
 }
 
-void ArgsVisitor::visit(ArgsOption * const arg)
+void ArgsVisitor::visit(StringArg & arg)
 {
-    arg->set_specified(true);
+    arg.set_specified(true);
 
     if (! _env_prefix.empty())
-        setenv(env_name(arg->long_name()).c_str(), "1", 1);
-}
+        setenv(env_name(arg.long_name()).c_str(), "1", 1);
 
-void ArgsVisitor::visit(StringArg * const arg)
-{
-    visit(static_cast<ArgsOption *>(arg));
     std::string p(get_param(arg));
-    arg->set_argument(p);
+    arg.set_argument(p);
 
     if (! _env_prefix.empty())
-        setenv(env_name(arg->long_name()).c_str(), p.c_str(), 1);
+        setenv(env_name(arg.long_name()).c_str(), p.c_str(), 1);
 }
 
-void ArgsVisitor::visit(AliasArg * const arg)
+void ArgsVisitor::visit(AliasArg & arg)
 {
-    arg->other()->accept(this);
+    arg.other()->accept(*this);
 }
 
-void ArgsVisitor::visit(SwitchArg * const arg)
+void ArgsVisitor::visit(SwitchArg & arg)
 {
-    visit(static_cast<ArgsOption *>(arg));
+    arg.set_specified(true);
+
+    if (! _env_prefix.empty())
+        setenv(env_name(arg.long_name()).c_str(), "1", 1);
 }
 
-void ArgsVisitor::visit(IntegerArg * const arg)
+void ArgsVisitor::visit(IntegerArg & arg)
 {
-    visit(static_cast<ArgsOption*>(arg));
+    arg.set_specified(true);
+
+    if (! _env_prefix.empty())
+        setenv(env_name(arg.long_name()).c_str(), "1", 1);
+
     std::string param = get_param(arg);
     try
     {
         int a(destringify<int>(param));
-        arg->set_argument(a);
+        arg.set_argument(a);
 
         if (! _env_prefix.empty())
-            setenv(env_name(arg->long_name()).c_str(), stringify(a).c_str(), 1);
+            setenv(env_name(arg.long_name()).c_str(), stringify(a).c_str(), 1);
     }
     catch (const DestringifyError &)
     {
-        throw BadValue("--" + arg->long_name(), param);
+        throw BadValue("--" + arg.long_name(), param);
     }
 }
 
-void ArgsVisitor::visit(EnumArg * const arg)
+void ArgsVisitor::visit(EnumArg & arg)
 {
-    visit(static_cast<ArgsOption*>(arg));
+    arg.set_specified(true);
+
+    if (! _env_prefix.empty())
+        setenv(env_name(arg.long_name()).c_str(), "1", 1);
+
     std::string p(get_param(arg));
-    arg->set_argument(p);
+    arg.set_argument(p);
 
     if (! _env_prefix.empty())
-        setenv(env_name(arg->long_name()).c_str(), p.c_str(), 1);
+        setenv(env_name(arg.long_name()).c_str(), p.c_str(), 1);
 }
 
-void ArgsVisitor::visit(StringSetArg * const arg)
+void ArgsVisitor::visit(StringSetArg & arg)
 {
-    visit(static_cast<ArgsOption *>(arg));
+    arg.set_specified(true);
+
+    if (! _env_prefix.empty())
+        setenv(env_name(arg.long_name()).c_str(), "1", 1);
+
     std::string param = get_param(arg);
-    arg->add_argument(param);
+    arg.add_argument(param);
 
     if (! _env_prefix.empty())
-        setenv(env_name(arg->long_name()).c_str(), join(arg->begin_args(),
-                    arg->end_args(), " ").c_str(), 1);
+        setenv(env_name(arg.long_name()).c_str(), join(arg.begin_args(),
+                    arg.end_args(), " ").c_str(), 1);
 }
 
 std::string
diff --git a/paludis/args/args_visitor.hh b/paludis/args/args_visitor.hh
index e60769ece..1d83eb800 100644
--- a/paludis/args/args_visitor.hh
+++ b/paludis/args/args_visitor.hh
@@ -50,8 +50,18 @@ namespace paludis
          *
          * \ingroup grplibpaludisargs
          */
-        typedef VisitorTypes<ArgsOption *, StringArg *, AliasArg *, SwitchArg *,
-                IntegerArg *, EnumArg *, StringSetArg *> ArgsVisitorTypes;
+        struct ArgsVisitorTypes :
+            VisitorTypes<
+                ArgsVisitorTypes,
+                ArgsOption,
+                StringArg,
+                AliasArg,
+                SwitchArg,
+                IntegerArg,
+                EnumArg,
+                StringSetArg>
+        {
+        };
 
         /**
          * Visitor class. Processes command-line options as they are found.
@@ -59,13 +69,13 @@ namespace paludis
          * \ingroup grplibpaludisargs
          */
         class PALUDIS_VISIBLE ArgsVisitor :
-            public ArgsVisitorTypes::Visitor
+            public MutableVisitor<ArgsVisitorTypes>
         {
             private:
                 libwrapiter::ForwardIterator<ArgsVisitor, std::string> * _args_index, _args_end;
                 std::string _env_prefix;
 
-                const std::string & get_param(const ArgsOption * const);
+                const std::string & get_param(const ArgsOption &);
 
                 std::string env_name(const std::string & long_name) const;
 
@@ -77,26 +87,23 @@ namespace paludis
                         libwrapiter::ForwardIterator<ArgsVisitor, std::string>,
                         const std::string & env_prefix = "");
 
-                /// Visit an ArgsOption.
-                void visit(ArgsOption * const);
-
                 /// Visit a StringArg.
-                void visit(StringArg * const);
+                void visit(StringArg &);
 
                 /// Visit an AliasArg.
-                void visit(AliasArg * const);
+                void visit(AliasArg &);
 
                 /// Visit a SwitchArg.
-                void visit(SwitchArg * const);
+                void visit(SwitchArg &);
 
                 /// Visit an IntegerArg.
-                void visit(IntegerArg * const);
+                void visit(IntegerArg &);
 
                 /// Visit an EnumArg.
-                void visit(EnumArg * const);
+                void visit(EnumArg &);
 
                 /// Visit a StringSetArg.
-                void visit(StringSetArg * const);
+                void visit(StringSetArg &);
         };
     }
 }
diff --git a/paludis/args/man.cc b/paludis/args/man.cc
index 13ccc32ce..121e796bb 100644
--- a/paludis/args/man.cc
+++ b/paludis/args/man.cc
@@ -18,6 +18,7 @@
  */
 
 #include "man.hh"
+#include <paludis/util/visitor-impl.hh>
 #include <ostream>
 #include <sstream>
 
@@ -28,7 +29,7 @@ using std::endl;
 namespace
 {
     struct ExtraText :
-        ArgsVisitorTypes::ConstVisitor
+        ConstVisitor<ArgsVisitorTypes>
     {
         DocWriter & _dw;
 
@@ -37,50 +38,50 @@ namespace
         {
         }
 
-        void visit(const ArgsOption * const)
+        void visit(const ArgsOption &)
         {
         }
 
-        void visit(const StringArg * const)
+        void visit(const StringArg &)
         {
         }
 
-        void visit(const AliasArg * const)
+        void visit(const AliasArg &)
         {
         }
 
-        void visit(const SwitchArg * const)
+        void visit(const SwitchArg &)
         {
         }
 
-        void visit(const IntegerArg * const)
+        void visit(const IntegerArg &)
         {
         }
 
-        void visit(const EnumArg * const e)
+        void visit(const EnumArg & e)
         {
-            if (e->begin_allowed_args() == e->end_allowed_args())
+            if (e.begin_allowed_args() == e.end_allowed_args())
                 return;
 
             _dw.start_extra_arg();
 
-            for (EnumArg::AllowedArgIterator a(e->begin_allowed_args()), a_end(e->end_allowed_args()) ;
+            for (EnumArg::AllowedArgIterator a(e.begin_allowed_args()), a_end(e.end_allowed_args()) ;
                     a != a_end ; ++a)
             {
-                _dw.extra_arg_enum(a->first, a->second, e->default_arg());
+                _dw.extra_arg_enum(a->first, a->second, e.default_arg());
             }
 
             _dw.end_extra_arg();
         }
 
-        void visit(const StringSetArg * const e)
+        void visit(const StringSetArg & e)
         {
-            if (e->begin_allowed_args() == e->end_allowed_args())
+            if (e.begin_allowed_args() == e.end_allowed_args())
                 return;
 
             _dw.start_extra_arg();
 
-            for (EnumArg::AllowedArgIterator a(e->begin_allowed_args()), a_end(e->end_allowed_args()) ;
+            for (EnumArg::AllowedArgIterator a(e.begin_allowed_args()), a_end(e.end_allowed_args()) ;
                     a != a_end ; ++a)
             {
                 _dw.extra_arg_string_set(a->first, a->second);
@@ -116,7 +117,7 @@ paludis::args::generate_doc(DocWriter & dw, const ArgsHandler * const h)
             dw.arg_group_item((*b)->short_name(), (*b)->long_name(), (*b)->description());
 
             ExtraText t(dw);
-            (*b)->accept(&t);
+            (*b)->accept(t);
 
             dw.end_arg_group();
         }