slot to requirements

51 files changed, 455 insertions, 587 deletions

diff --git a/doc/api/cplusplus/examples/example_dep_spec.cc b/doc/api/cplusplus/examples/example_dep_spec.cc
index 71b6c93..8b72b16 100644
--- a/doc/api/cplusplus/examples/example_dep_spec.cc
+++ b/doc/api/cplusplus/examples/example_dep_spec.cc
@@ -98,8 +98,8 @@ int main(int argc, char * argv[])
                 cout << endl;
             }
 
-            if (spec.slot_requirement_ptr())
-                cout << "    " << left << setw(24) << "Slot:" << " " << *spec.slot_requirement_ptr() << endl;
+            if (spec.exact_slot_constraint())
+                cout << "    " << left << setw(24) << "Slot:" << " " << spec.exact_slot_constraint()->name() << endl;
 
             if (spec.in_repository_constraint())
                 cout << "    " << left << setw(24) << "In repository:" << " " <<
diff --git a/paludis/common_sets.cc b/paludis/common_sets.cc
index 183c2a4..308e3b8 100644
--- a/paludis/common_sets.cc
+++ b/paludis/common_sets.cc
@@ -1,7 +1,7 @@
 /* vim: set sw=4 sts=4 et foldmethod=syntax : */
 
 /*
- * Copyright (c) 2009, 2010 Ciaran McCreesh
+ * Copyright (c) 2009, 2010, 2011 Ciaran McCreesh
  *
  * This file is part of the Paludis package manager. Paludis is free software;
  * you can redistribute it and/or modify it under the terms of the GNU General
@@ -27,7 +27,6 @@
 #include <paludis/filtered_generator.hh>
 #include <paludis/metadata_key.hh>
 #include <paludis/package_id.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
 #include <paludis/util/sequence.hh>
 #include <paludis/util/wrapped_forward_iterator.hh>
@@ -59,8 +58,7 @@ namespace
                 result->top()->append(std::make_shared<PackageDepSpec>(
                                 make_package_dep_spec({ })
                                 .package((*i)->name())
-                                .slot_requirement(std::make_shared<ELikeSlotExactRequirement>(
-                                            (*i)->slot_key()->value(), false))
+                                .exact_slot_constraint((*i)->slot_key()->value(), false)
                                 ));
             else
                 result->top()->append(std::make_shared<PackageDepSpec>(
diff --git a/paludis/dep_spec.cc b/paludis/dep_spec.cc
index 4b5fe74..432f0fb 100644
--- a/paludis/dep_spec.cc
+++ b/paludis/dep_spec.cc
@@ -572,10 +572,16 @@ PackageDepSpec::version_requirements_mode() const
     return _imp->data->version_requirements_mode();
 }
 
-std::shared_ptr<const SlotRequirement>
-PackageDepSpec::slot_requirement_ptr() const
+const std::shared_ptr<const AnySlotConstraint>
+PackageDepSpec::any_slot_constraint() const
 {
-    return _imp->data->slot_requirement_ptr();
+    return _imp->data->any_slot_constraint();
+}
+
+const std::shared_ptr<const ExactSlotConstraint>
+PackageDepSpec::exact_slot_constraint() const
+{
+    return _imp->data->exact_slot_constraint();
 }
 
 const std::shared_ptr<const InRepositoryConstraint>
diff --git a/paludis/dep_spec.hh b/paludis/dep_spec.hh
index d99e9f1..9c6bb9a 100644
--- a/paludis/dep_spec.hh
+++ b/paludis/dep_spec.hh
@@ -34,7 +34,6 @@
 #include <paludis/version_operator-fwd.hh>
 #include <paludis/version_requirements-fwd.hh>
 #include <paludis/version_spec-fwd.hh>
-#include <paludis/slot_requirement-fwd.hh>
 #include <paludis/package_id-fwd.hh>
 #include <paludis/environment-fwd.hh>
 #include <paludis/additional_package_dep_spec_requirement-fwd.hh>
@@ -351,9 +350,20 @@ namespace paludis
             VersionRequirementsMode version_requirements_mode() const;
 
             /**
-             * Fetch the slot requirement (may be a zero pointer).
+             * Fetch the single ExactSlotConstraint, if we have one, or
+             * a null pointer otherwise.
+             *
+             * \since 0.61
+             */
+            const std::shared_ptr<const ExactSlotConstraint> exact_slot_constraint() const;
+
+            /**
+             * Fetch the single AnySlotConstraint, if we have one, or
+             * a null pointer otherwise.
+             *
+             * \since 0.61
              */
-            std::shared_ptr<const SlotRequirement> slot_requirement_ptr() const;
+            const std::shared_ptr<const AnySlotConstraint> any_slot_constraint() const;
 
             /**
              * Fetch the single InRepositoryConstraint, if we have one, or
diff --git a/paludis/dep_spec_data.hh b/paludis/dep_spec_data.hh
index 4652caf..6f4dc64 100644
--- a/paludis/dep_spec_data.hh
+++ b/paludis/dep_spec_data.hh
@@ -27,7 +27,6 @@
 #include <paludis/name-fwd.hh>
 #include <paludis/version_operator-fwd.hh>
 #include <paludis/version_requirements-fwd.hh>
-#include <paludis/slot_requirement-fwd.hh>
 #include <paludis/additional_package_dep_spec_requirement-fwd.hh>
 #include <paludis/dep_spec-fwd.hh>
 #include <paludis/partially_made_package_dep_spec-fwd.hh>
@@ -148,9 +147,20 @@ namespace paludis
             virtual VersionRequirementsMode version_requirements_mode() const = 0;
 
             /**
-             * Fetch the slot name (may be a zero pointer).
+             * Fetch the single ExactSlotConstraint, if we have one, or
+             * a null pointer otherwise.
+             *
+             * \since 0.61
+             */
+            virtual const std::shared_ptr<const ExactSlotConstraint> exact_slot_constraint() const = 0;
+
+            /**
+             * Fetch the single AnySlotConstraint, if we have one, or
+             * a null pointer otherwise.
+             *
+             * \since 0.61
              */
-            virtual std::shared_ptr<const SlotRequirement> slot_requirement_ptr() const = 0;
+            virtual const std::shared_ptr<const AnySlotConstraint> any_slot_constraint() const = 0;
 
             /**
              * Fetch the single InRepositoryConstraint, if we have one, or
diff --git a/paludis/elike_package_dep_spec.cc b/paludis/elike_package_dep_spec.cc
index 91433ef..1c70cdb 100644
--- a/paludis/elike_package_dep_spec.cc
+++ b/paludis/elike_package_dep_spec.cc
@@ -19,7 +19,6 @@
 
 #include <paludis/elike_package_dep_spec.hh>
 #include <paludis/elike_use_requirement.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/util/options.hh>
 #include <paludis/util/log.hh>
 #include <paludis/util/make_named_values.hh>
@@ -292,7 +291,7 @@ paludis::elike_remove_trailing_slot_if_exists(std::string & s, PartiallyMadePack
                 Log::get_instance()->message("e.package_dep_spec.slot_star_not_allowed", ll_warning, lc_context)
                     << "Slot '*' dependencies not safe for use here";
         }
-        result.slot_requirement(std::make_shared<ELikeSlotAnyUnlockedRequirement>());
+        result.any_slot_constraint(false);
     }
     else if ('=' == match.at(0))
     {
@@ -306,9 +305,9 @@ paludis::elike_remove_trailing_slot_if_exists(std::string & s, PartiallyMadePack
         }
 
         if (1 == match.length())
-            result.slot_requirement(std::make_shared<ELikeSlotAnyLockedRequirement>());
+            result.any_slot_constraint(true);
         else
-            result.slot_requirement(std::make_shared<ELikeSlotExactRequirement>(SlotName(s.substr(slot_p + 2)), true));
+            result.exact_slot_constraint(SlotName(s.substr(slot_p + 2)), true);
     }
     else
     {
@@ -320,7 +319,7 @@ paludis::elike_remove_trailing_slot_if_exists(std::string & s, PartiallyMadePack
                 Log::get_instance()->message("e.package_dep_spec.slot_not_allowed", ll_warning, lc_context)
                     << "Slot dependencies not safe for use here";
         }
-        result.slot_requirement(std::make_shared<ELikeSlotExactRequirement>(SlotName(s.substr(slot_p + 1)), false));
+        result.exact_slot_constraint(SlotName(s.substr(slot_p + 1)), false);
     }
     s.erase(slot_p);
 }
diff --git a/paludis/elike_slot_requirement-fwd.hh b/paludis/elike_slot_requirement-fwd.hh
deleted file mode 100644
index 9ec1513..0000000
--- a/paludis/elike_slot_requirement-fwd.hh
+++ /dev/null
@@ -1,30 +0,0 @@
-/* vim: set sw=4 sts=4 et foldmethod=syntax : */
-
-/*
- * Copyright (c) 2008 Ciaran McCreesh
- *
- * This file is part of the Paludis package manager. Paludis is free software;
- * you can redistribute it and/or modify it under the terms of the GNU General
- * Public License version 2, as published by the Free Software Foundation.
- *
- * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#ifndef PALUDIS_GUARD_PALUDIS_ELIKE_SLOT_REQUIREMENT_FWD_HH
-#define PALUDIS_GUARD_PALUDIS_ELIKE_SLOT_REQUIREMENT_FWD_HH 1
-
-namespace paludis
-{
-    class ELikeSlotExactRequirement;
-    class ELikeSlotAnyLockedRequirement;
-    class ELikeSlotAnyUnlockedRequirement;
-}
-
-#endif
diff --git a/paludis/elike_slot_requirement.cc b/paludis/elike_slot_requirement.cc
deleted file mode 100644
index ea52fe4..0000000
--- a/paludis/elike_slot_requirement.cc
+++ /dev/null
@@ -1,54 +0,0 @@
-/* vim: set sw=4 sts=4 et foldmethod=syntax : */
-
-/*
- * Copyright (c) 2008 Ciaran McCreesh
- *
- * This file is part of the Paludis package manager. Paludis is free software;
- * you can redistribute it and/or modify it under the terms of the GNU General
- * Public License version 2, as published by the Free Software Foundation.
- *
- * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#include <paludis/elike_slot_requirement.hh>
-#include <paludis/util/stringify.hh>
-
-using namespace paludis;
-
-ELikeSlotExactRequirement::ELikeSlotExactRequirement(const SlotName & s, const bool e) :
-    _s(s),
-    _e(e)
-{
-}
-
-const std::string
-ELikeSlotExactRequirement::as_string() const
-{
-    return ":" + std::string(_e ? "=" : "") + stringify(_s);
-}
-
-const SlotName
-ELikeSlotExactRequirement::slot() const
-{
-    return _s;
-}
-
-const std::string
-ELikeSlotAnyUnlockedRequirement::as_string() const
-{
-    return ":*";
-}
-
-const std::string
-ELikeSlotAnyLockedRequirement::as_string() const
-{
-    return ":=";
-}
-
diff --git a/paludis/elike_slot_requirement.hh b/paludis/elike_slot_requirement.hh
deleted file mode 100644
index ad33609..0000000
--- a/paludis/elike_slot_requirement.hh
+++ /dev/null
@@ -1,58 +0,0 @@
-/* vim: set sw=4 sts=4 et foldmethod=syntax : */
-
-/*
- * Copyright (c) 2008 Ciaran McCreesh
- *
- * This file is part of the Paludis package manager. Paludis is free software;
- * you can redistribute it and/or modify it under the terms of the GNU General
- * Public License version 2, as published by the Free Software Foundation.
- *
- * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#ifndef PALUDIS_GUARD_PALUDIS_ELIKE_SLOT_REQUIREMENT_HH
-#define PALUDIS_GUARD_PALUDIS_ELIKE_SLOT_REQUIREMENT_HH 1
-
-#include <paludis/elike_slot_requirement-fwd.hh>
-#include <paludis/slot_requirement.hh>
-#include <paludis/name.hh>
-
-namespace paludis
-{
-    class PALUDIS_VISIBLE ELikeSlotExactRequirement :
-        public SlotExactRequirement
-    {
-        private:
-            const SlotName _s;
-            const bool _e;
-
-        public:
-            ELikeSlotExactRequirement(const SlotName &, const bool equals);
-
-            virtual const std::string as_string() const PALUDIS_ATTRIBUTE((warn_unused_result));
-            virtual const SlotName slot() const PALUDIS_ATTRIBUTE((warn_unused_result));
-    };
-
-    class PALUDIS_VISIBLE ELikeSlotAnyUnlockedRequirement :
-        public SlotAnyUnlockedRequirement
-    {
-        public:
-            virtual const std::string as_string() const PALUDIS_ATTRIBUTE((warn_unused_result));
-    };
-
-    class PALUDIS_VISIBLE ELikeSlotAnyLockedRequirement :
-        public SlotAnyLockedRequirement
-    {
-        public:
-            virtual const std::string as_string() const PALUDIS_ATTRIBUTE((warn_unused_result));
-    };
-}
-
-#endif
diff --git a/paludis/files.m4 b/paludis/files.m4
index abc367b..7b69c2d 100644
--- a/paludis/files.m4
+++ b/paludis/files.m4
@@ -38,7 +38,6 @@ add(`elike_choices',                               `hh', `cc', `fwd', `se')
 add(`elike_dep_parser',                            `hh', `cc', `fwd', `gtest', `se')
 add(`elike_conditional_dep_spec',                  `hh', `cc', `fwd')
 add(`elike_package_dep_spec',                      `hh', `cc', `fwd', `se')
-add(`elike_slot_requirement',                      `hh', `cc', `fwd')
 add(`elike_use_requirement',                       `hh', `cc', `fwd', `se', `gtest')
 add(`environment',                                 `hh', `fwd', `cc')
 add(`environment_factory',                         `hh', `fwd', `cc')
@@ -93,7 +92,6 @@ add(`selection_cache',                             `hh', `cc', `fwd')
 add(`selection_handler',                           `hh', `cc', `fwd')
 add(`serialise',                                   `hh', `cc', `fwd', `impl')
 add(`set_file',                                    `hh', `cc', `se', `gtest', `testscript')
-add(`slot_requirement',                            `hh', `fwd', `cc')
 add(`spec_tree',                                   `hh', `fwd', `cc')
 add(`standard_output_manager',                     `hh', `cc', `fwd')
 add(`stripper',                                    `hh', `cc', `fwd', `gtest', `testscript')
diff --git a/paludis/generator.cc b/paludis/generator.cc
index 1484bbb..bc5dcda 100644
--- a/paludis/generator.cc
+++ b/paludis/generator.cc
@@ -306,7 +306,9 @@ namespace
         {
             if (package_dep_spec_has_properties(spec, make_named_values<PackageDepSpecProperties>(
                             n::has_additional_requirements() = indeterminate,
+                            n::has_any_slot_requirement() = indeterminate,
                             n::has_category_name_part() = indeterminate,
+                            n::has_exact_slot_requirement() = indeterminate,
                             n::has_from_repository() = indeterminate,
                             n::has_in_repository() = false,
                             n::has_installable_to_path() = indeterminate,
@@ -314,7 +316,6 @@ namespace
                             n::has_installed_at_path() = false,
                             n::has_package() = indeterminate,
                             n::has_package_name_part() = indeterminate,
-                            n::has_slot_requirement() = indeterminate,
                             n::has_tag() = indeterminate,
                             n::has_version_requirements() = indeterminate
                             )))
diff --git a/paludis/match_package.cc b/paludis/match_package.cc
index 9995bf3..424628f 100644
--- a/paludis/match_package.cc
+++ b/paludis/match_package.cc
@@ -23,7 +23,6 @@
 #include <paludis/environment.hh>
 #include <paludis/version_requirements.hh>
 #include <paludis/package_id.hh>
-#include <paludis/slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 #include <paludis/action.hh>
 #include <paludis/repository.hh>
@@ -47,36 +46,6 @@ using namespace paludis;
 
 #include <paludis/match_package-se.cc>
 
-namespace
-{
-    struct SlotRequirementChecker
-    {
-        const std::shared_ptr<const PackageID> id;
-        bool result;
-
-        SlotRequirementChecker(const std::shared_ptr<const PackageID> & i) :
-            id(i),
-            result(true)
-        {
-        }
-
-        void visit(const SlotExactRequirement & s)
-        {
-            result = id->slot_key() && id->slot_key()->value() == s.slot();
-        }
-
-        void visit(const SlotAnyLockedRequirement &)
-        {
-            result = true;
-        }
-
-        void visit(const SlotAnyUnlockedRequirement &)
-        {
-            result = true;
-        }
-    };
-}
-
 bool
 paludis::match_package_with_maybe_changes(
         const Environment & env,
@@ -194,14 +163,17 @@ paludis::match_package_with_maybe_changes(
             return false;
     }
 
-    if (spec.slot_requirement_ptr())
+    if (spec.exact_slot_constraint())
     {
-        SlotRequirementChecker v(id);
-        spec.slot_requirement_ptr()->accept(v);
-        if (! v.result)
+        if ((! id->slot_key()) || (id->slot_key()->value() != spec.exact_slot_constraint()->name()))
             return false;
     }
 
+    if (spec.any_slot_constraint())
+    {
+        /* don't care */
+    }
+
     if (! options[mpo_ignore_additional_requirements])
     {
         if (spec.additional_requirements_ptr())
diff --git a/paludis/package_dep_spec_constraint-fwd.hh b/paludis/package_dep_spec_constraint-fwd.hh
index b949a2b..b8c43a6 100644
--- a/paludis/package_dep_spec_constraint-fwd.hh
+++ b/paludis/package_dep_spec_constraint-fwd.hh
@@ -49,6 +49,12 @@ namespace paludis
 
     class InstallableToRepositoryConstraint;
     typedef Pool<InstallableToRepositoryConstraint> InstallableToRepositoryConstraintPool;
+
+    class ExactSlotConstraint;
+    typedef Pool<ExactSlotConstraint> ExactSlotConstraintPool;
+
+    class AnySlotConstraint;
+    typedef Pool<AnySlotConstraint> AnySlotConstraintPool;
 }
 
 #endif
diff --git a/paludis/package_dep_spec_constraint.cc b/paludis/package_dep_spec_constraint.cc
index dc1f4ad..b1e6b96 100644
--- a/paludis/package_dep_spec_constraint.cc
+++ b/paludis/package_dep_spec_constraint.cc
@@ -184,3 +184,44 @@ template class Singleton<Pool<InstallableToRepositoryConstraint> >;
 template const std::shared_ptr<const InstallableToRepositoryConstraint> Pool<InstallableToRepositoryConstraint>::create(
         const RepositoryName &, const bool & ...) const;
 
+ExactSlotConstraint::ExactSlotConstraint(const SlotName & n, const bool i) :
+    _name(n),
+    _locked(i)
+{
+}
+
+ExactSlotConstraint::~ExactSlotConstraint() = default;
+
+const SlotName
+ExactSlotConstraint::name() const
+{
+    return _name;
+}
+
+bool
+ExactSlotConstraint::locked() const
+{
+    return _locked;
+}
+
+template class Pool<ExactSlotConstraint>;
+template class Singleton<Pool<ExactSlotConstraint> >;
+template const std::shared_ptr<const ExactSlotConstraint> Pool<ExactSlotConstraint>::create(const SlotName &, const bool & ...) const;
+
+AnySlotConstraint::AnySlotConstraint(const bool i) :
+    _locking(i)
+{
+}
+
+AnySlotConstraint::~AnySlotConstraint() = default;
+
+bool
+AnySlotConstraint::locking() const
+{
+    return _locking;
+}
+
+template class Pool<AnySlotConstraint>;
+template class Singleton<Pool<AnySlotConstraint> >;
+template const std::shared_ptr<const AnySlotConstraint> Pool<AnySlotConstraint>::create(const bool &) const;
+
diff --git a/paludis/package_dep_spec_constraint.hh b/paludis/package_dep_spec_constraint.hh
index 7e71bd6..f23ba66 100644
--- a/paludis/package_dep_spec_constraint.hh
+++ b/paludis/package_dep_spec_constraint.hh
@@ -40,7 +40,9 @@ namespace paludis
             FromRepositoryConstraint,
             InstalledAtPathConstraint,
             InstallableToPathConstraint,
-            InstallableToRepositoryConstraint
+            InstallableToRepositoryConstraint,
+            AnySlotConstraint,
+            ExactSlotConstraint
         >::Type>
     {
         public:
@@ -203,6 +205,46 @@ namespace paludis
             bool include_masked() const PALUDIS_ATTRIBUTE((warn_unused_result));
     };
 
+    class PALUDIS_VISIBLE ExactSlotConstraint :
+        public PackageDepSpecConstraint,
+        public ImplementAcceptMethods<PackageDepSpecConstraint, ExactSlotConstraint>
+    {
+        friend class Pool<ExactSlotConstraint>;
+
+        private:
+            SlotName _name;
+            bool _locked;
+
+            ExactSlotConstraint(const SlotName &, const bool);
+
+            ExactSlotConstraint(const ExactSlotConstraint &) = delete;
+
+        public:
+            ~ExactSlotConstraint();
+
+            const SlotName name() const PALUDIS_ATTRIBUTE((warn_unused_result));
+            bool locked() const PALUDIS_ATTRIBUTE((warn_unused_result));
+    };
+
+    class PALUDIS_VISIBLE AnySlotConstraint :
+        public PackageDepSpecConstraint,
+        public ImplementAcceptMethods<PackageDepSpecConstraint, AnySlotConstraint>
+    {
+        friend class Pool<AnySlotConstraint>;
+
+        private:
+            bool _locking;
+
+            AnySlotConstraint(const bool);
+
+            AnySlotConstraint(const AnySlotConstraint &) = delete;
+
+        public:
+            ~AnySlotConstraint();
+
+            bool locking() const PALUDIS_ATTRIBUTE((warn_unused_result));
+    };
+
     extern template class Pool<NameConstraint>;
     extern template class Pool<PackageNamePartConstraint>;
     extern template class Pool<CategoryNamePartConstraint>;
@@ -211,6 +253,8 @@ namespace paludis
     extern template class Pool<InstalledAtPathConstraint>;
     extern template class Pool<InstallableToPathConstraint>;
     extern template class Pool<InstallableToRepositoryConstraint>;
+    extern template class Pool<ExactSlotConstraint>;
+    extern template class Pool<AnySlotConstraint>;
 }
 
 #endif
diff --git a/paludis/package_dep_spec_properties.cc b/paludis/package_dep_spec_properties.cc
index dbb057f..000b20c 100644
--- a/paludis/package_dep_spec_properties.cc
+++ b/paludis/package_dep_spec_properties.cc
@@ -50,7 +50,8 @@ paludis::package_dep_spec_has_properties(const PackageDepSpec & spec, const Pack
     result = result && check(bool(spec.installed_at_path_constraint()), properties.has_installed_at_path());
     result = result && check(bool(spec.package_name_constraint()), properties.has_package());
     result = result && check(bool(spec.package_name_part_constraint()), properties.has_package_name_part());
-    result = result && check(bool(spec.slot_requirement_ptr()), properties.has_slot_requirement());
+    result = result && check(bool(spec.exact_slot_constraint()), properties.has_exact_slot_requirement());
+    result = result && check(bool(spec.any_slot_constraint()), properties.has_any_slot_requirement());
     result = result && check(spec.version_requirements_ptr() && ! spec.version_requirements_ptr()->empty(), properties.has_version_requirements());
 
     return result;
diff --git a/paludis/package_dep_spec_properties.hh b/paludis/package_dep_spec_properties.hh
index 45ed0fa..e9eff06 100644
--- a/paludis/package_dep_spec_properties.hh
+++ b/paludis/package_dep_spec_properties.hh
@@ -1,7 +1,7 @@
 /* vim: set sw=4 sts=4 et foldmethod=syntax : */
 
 /*
- * Copyright (c) 2009, 2010 Ciaran McCreesh
+ * Copyright (c) 2009, 2010, 2011 Ciaran McCreesh
  *
  * This file is part of the Paludis package manager. Paludis is free software;
  * you can redistribute it and/or modify it under the terms of the GNU General
@@ -29,7 +29,9 @@ namespace paludis
     namespace n
     {
         typedef Name<struct name_has_additional_requirements> has_additional_requirements;
+        typedef Name<struct name_has_any_slot_requirement> has_any_slot_requirement;
         typedef Name<struct name_has_category_name_part> has_category_name_part;
+        typedef Name<struct name_has_exact_slot_requirement> has_exact_slot_requirement;
         typedef Name<struct name_has_from_repository> has_from_repository;
         typedef Name<struct name_has_in_repository> has_in_repository;
         typedef Name<struct name_has_installable_to_path> has_installable_to_path;
@@ -37,7 +39,6 @@ namespace paludis
         typedef Name<struct name_has_installed_at_path> has_installed_at_path;
         typedef Name<struct name_has_package> has_package;
         typedef Name<struct name_has_package_name_part> has_package_name_part;
-        typedef Name<struct name_has_slot_requirement> has_slot_requirement;
         typedef Name<struct name_has_tag> has_tag;
         typedef Name<struct name_has_version_requirements> has_version_requirements;
     }
@@ -51,7 +52,9 @@ namespace paludis
     struct PackageDepSpecProperties
     {
         NamedValue<n::has_additional_requirements, Tribool> has_additional_requirements;
+        NamedValue<n::has_any_slot_requirement, Tribool> has_any_slot_requirement;
         NamedValue<n::has_category_name_part, Tribool> has_category_name_part;
+        NamedValue<n::has_exact_slot_requirement, Tribool> has_exact_slot_requirement;
         NamedValue<n::has_from_repository, Tribool> has_from_repository;
         NamedValue<n::has_in_repository, Tribool> has_in_repository;
         NamedValue<n::has_installable_to_path, Tribool> has_installable_to_path;
@@ -59,7 +62,6 @@ namespace paludis
         NamedValue<n::has_installed_at_path, Tribool> has_installed_at_path;
         NamedValue<n::has_package, Tribool> has_package;
         NamedValue<n::has_package_name_part, Tribool> has_package_name_part;
-        NamedValue<n::has_slot_requirement, Tribool> has_slot_requirement;
         NamedValue<n::has_tag, Tribool> has_tag;
         NamedValue<n::has_version_requirements, Tribool> has_version_requirements;
     };
diff --git a/paludis/paludislike_options_conf.cc b/paludis/paludislike_options_conf.cc
index 471f437..8af91db 100644
--- a/paludis/paludislike_options_conf.cc
+++ b/paludis/paludislike_options_conf.cc
@@ -342,7 +342,9 @@ namespace
     {
         return package_dep_spec_has_properties(spec, make_named_values<PackageDepSpecProperties>(
                     n::has_additional_requirements() = false,
+                    n::has_any_slot_requirement() = indeterminate,
                     n::has_category_name_part() = false,
+                    n::has_exact_slot_requirement() = false,
                     n::has_from_repository() = false,
                     n::has_in_repository() = false,
                     n::has_installable_to_path() = false,
@@ -350,7 +352,6 @@ namespace
                     n::has_installed_at_path() = false,
                     n::has_package() = false,
                     n::has_package_name_part() = false,
-                    n::has_slot_requirement() = false,
                     n::has_tag() = false,
                     n::has_version_requirements() = false
                     ));
diff --git a/paludis/partially_made_package_dep_spec.cc b/paludis/partially_made_package_dep_spec.cc
index 5de8177..b070d0c 100644
--- a/paludis/partially_made_package_dep_spec.cc
+++ b/paludis/partially_made_package_dep_spec.cc
@@ -53,7 +53,8 @@ namespace
         std::shared_ptr<const CategoryNamePartConstraint> category_name_part;
         std::shared_ptr<VersionRequirements> version_requirements;
         VersionRequirementsMode version_requirements_mode_v;
-        std::shared_ptr<const SlotRequirement> slot;
+        std::shared_ptr<const AnySlotConstraint> any_slot;
+        std::shared_ptr<const ExactSlotConstraint> exact_slot;
         std::shared_ptr<const InRepositoryConstraint> in_repository;
         std::shared_ptr<const FromRepositoryConstraint> from_repository;
         std::shared_ptr<const InstallableToRepositoryConstraint> installable_to_repository;
@@ -76,7 +77,8 @@ namespace
             category_name_part(other.category_name_part_constraint()),
             version_requirements(other.version_requirements_ptr() ? new VersionRequirements : 0),
             version_requirements_mode_v(other.version_requirements_mode()),
-            slot(other.slot_requirement_ptr()),
+            any_slot(other.any_slot_constraint()),
+            exact_slot(other.exact_slot_constraint()),
             in_repository(other.in_repository_constraint()),
             from_repository(other.from_repository_constraint()),
             installable_to_repository(other.installable_to_repository_constraint()),
@@ -101,7 +103,8 @@ namespace
             category_name_part(other.category_name_part),
             version_requirements(other.version_requirements),
             version_requirements_mode_v(other.version_requirements_mode_v),
-            slot(other.slot),
+            any_slot(other.any_slot),
+            exact_slot(other.exact_slot),
             in_repository(other.in_repository),
             from_repository(other.from_repository),
             installable_to_repository(other.installable_to_repository),
@@ -162,8 +165,23 @@ namespace
                 }
             }
 
-            if (slot_requirement_ptr())
-                s << stringify(*slot_requirement_ptr());
+            if (exact_slot_constraint())
+            {
+                if (exact_slot_constraint()->locked())
+                    s << ":=";
+                else
+                    s << ":";
+
+                s << stringify(exact_slot_constraint()->name());
+            }
+
+            if (any_slot_constraint())
+            {
+                if (any_slot_constraint()->locking())
+                    s << ":=";
+                else
+                    s << ":*";
+            }
 
             std::string left, right;
             bool need_arrow(false);
@@ -303,9 +321,14 @@ namespace
             return version_requirements_mode_v;
         }
 
-        virtual std::shared_ptr<const SlotRequirement> slot_requirement_ptr() const
+        virtual const std::shared_ptr<const ExactSlotConstraint> exact_slot_constraint() const
+        {
+            return exact_slot;
+        }
+
+        virtual const std::shared_ptr<const AnySlotConstraint> any_slot_constraint() const
         {
-            return slot;
+            return any_slot;
         }
 
         virtual const std::shared_ptr<const InRepositoryConstraint> in_repository_constraint() const
@@ -403,16 +426,30 @@ PartiallyMadePackageDepSpec::clear_package()
 }
 
 PartiallyMadePackageDepSpec &
-PartiallyMadePackageDepSpec::slot_requirement(const std::shared_ptr<const SlotRequirement> & s)
+PartiallyMadePackageDepSpec::any_slot_constraint(const bool s)
+{
+    _imp->data->any_slot = AnySlotConstraintPool::get_instance()->create(s);
+    return *this;
+}
+
+PartiallyMadePackageDepSpec &
+PartiallyMadePackageDepSpec::exact_slot_constraint(const SlotName & n, const bool s)
+{
+    _imp->data->exact_slot = ExactSlotConstraintPool::get_instance()->create(n, s);
+    return *this;
+}
+
+PartiallyMadePackageDepSpec &
+PartiallyMadePackageDepSpec::clear_exact_slot()
 {
-    _imp->data->slot = s;
+    _imp->data->exact_slot.reset();
     return *this;
 }
 
 PartiallyMadePackageDepSpec &
-PartiallyMadePackageDepSpec::clear_slot_requirement()
+PartiallyMadePackageDepSpec::clear_any_slot()
 {
-    _imp->data->slot.reset();
+    _imp->data->any_slot.reset();
     return *this;
 }
 
diff --git a/paludis/partially_made_package_dep_spec.hh b/paludis/partially_made_package_dep_spec.hh
index 6eb9d5f..78f7d16 100644
--- a/paludis/partially_made_package_dep_spec.hh
+++ b/paludis/partially_made_package_dep_spec.hh
@@ -63,16 +63,34 @@ namespace paludis
             PartiallyMadePackageDepSpec & clear_package();
 
             /**
-             * Set our slot requirements, return ourself.
+             * Set our exact slot requirements, return ourself.
+             *
+             * \since 0.61
              */
-            PartiallyMadePackageDepSpec & slot_requirement(const std::shared_ptr<const SlotRequirement> &);
+            PartiallyMadePackageDepSpec & exact_slot_constraint(
+                    const SlotName &, const bool);
 
             /**
-             * Clear our slot requirements, return ourself.
+             * Set our locked slot requirements, return ourself.
              *
-             * \since 0.55
+             * \since 0.61
+             */
+             PartiallyMadePackageDepSpec & any_slot_constraint(
+                     const bool);
+
+            /**
+             * Clear our exact slot requirements, return ourself.
+             *
+             * \since 0.61
+             */
+            PartiallyMadePackageDepSpec & clear_exact_slot();
+
+            /**
+             * Clear our any slot requirements, return ourself.
+             *
+             * \since 0.61
              */
-            PartiallyMadePackageDepSpec & clear_slot_requirement();
+            PartiallyMadePackageDepSpec & clear_any_slot();
 
             /**
              * Set our in-repository requirement, return ourself.
diff --git a/paludis/repositories/e/e_repository_sets.cc b/paludis/repositories/e/e_repository_sets.cc
index 186b28b..d9f15fe 100644
--- a/paludis/repositories/e/e_repository_sets.cc
+++ b/paludis/repositories/e/e_repository_sets.cc
@@ -26,7 +26,6 @@
 
 #include <paludis/action-fwd.hh>
 #include <paludis/dep_spec.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/environment.hh>
 #include <paludis/filter.hh>
 #include <paludis/filtered_generator.hh>
diff --git a/paludis/repositories/e/fix_locked_dependencies.cc b/paludis/repositories/e/fix_locked_dependencies.cc
index bb61360..1f952e2 100644
--- a/paludis/repositories/e/fix_locked_dependencies.cc
+++ b/paludis/repositories/e/fix_locked_dependencies.cc
@@ -28,13 +28,13 @@
 #include <paludis/dep_spec.hh>
 #include <paludis/environment.hh>
 #include <paludis/package_id.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/selection.hh>
 #include <paludis/generator.hh>
 #include <paludis/filter.hh>
 #include <paludis/filtered_generator.hh>
 #include <paludis/metadata_key.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
+#include <paludis/package_dep_spec_constraint.hh>
 #include <functional>
 #include <algorithm>
 #include <list>
@@ -99,11 +99,7 @@ namespace
 
             do
             {
-                if (! node.spec()->slot_requirement_ptr())
-                    break;
-
-                const SlotAnyLockedRequirement * const r(visitor_cast<const SlotAnyLockedRequirement>(*node.spec()->slot_requirement_ptr()));
-                if (! r)
+                if ((! node.spec()->any_slot_constraint()) || (! node.spec()->any_slot_constraint()->locking()))
                     break;
 
                 std::shared_ptr<const PackageIDSequence> matches((*env)[selection::AllVersionsSorted(
@@ -113,8 +109,9 @@ namespace
 
                 if ((*matches->last())->slot_key())
                 {
-                    PackageDepSpec new_s(PartiallyMadePackageDepSpec(*node.spec()).slot_requirement(
-                                std::make_shared<ELikeSlotExactRequirement>((*matches->last())->slot_key()->value(), true)));
+                    PackageDepSpec new_s(PartiallyMadePackageDepSpec(*node.spec())
+                            .clear_any_slot()
+                            .exact_slot_constraint((*matches->last())->slot_key()->value(), true));
                     c = std::make_shared<PackageDepSpec>(new_s);
                 }
             } while (false);
diff --git a/paludis/repositories/virtuals/package_id.cc b/paludis/repositories/virtuals/package_id.cc
index a2231e5..f4f48a4 100644
--- a/paludis/repositories/virtuals/package_id.cc
+++ b/paludis/repositories/virtuals/package_id.cc
@@ -75,8 +75,7 @@ namespace paludis
                             .version_requirement(make_named_values<VersionRequirement>(
                                     n::version_operator() = vo_equal,
                                     n::version_spec() = v->version()))
-                            .slot_requirement(std::make_shared<UserSlotExactRequirement>(
-                                        v->slot_key() ? v->slot_key()->value() : SlotName("UNKNOWN")))
+                            .exact_slot_constraint(v->slot_key() ? v->slot_key()->value() : SlotName("UNKNOWN"), false)
                             .in_repository(v->repository_name()))
                     :
                     std::make_shared<PackageDepSpec>(
diff --git a/paludis/resolver/collect_depped_upon.cc b/paludis/resolver/collect_depped_upon.cc
index 46bfa86..257aae5 100644
--- a/paludis/resolver/collect_depped_upon.cc
+++ b/paludis/resolver/collect_depped_upon.cc
@@ -29,10 +29,10 @@
 #include <paludis/environment.hh>
 #include <paludis/package_id.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 #include <paludis/match_package.hh>
 #include <paludis/version_spec.hh>
+#include <paludis/package_dep_spec_constraint.hh>
 #include <algorithm>
 
 using namespace paludis;
@@ -108,8 +108,7 @@ namespace
             {
                 auto spec(s.spec());
 
-                if (s.spec()->slot_requirement_ptr() && visitor_cast<const SlotAnyUnlockedRequirement>(
-                            *s.spec()->slot_requirement_ptr()))
+                if (s.spec()->any_slot_constraint() && ! s.spec()->any_slot_constraint()->locking())
                 {
                     auto best_eventual_id(best_eventual(env, *s.spec(), id_for_specs, newly_available));
                     if (! best_eventual_id)
@@ -117,7 +116,7 @@ namespace
                     if (best_eventual_id && best_eventual_id->slot_key())
                     {
                         PartiallyMadePackageDepSpec part_spec(*s.spec());
-                        part_spec.slot_requirement(std::make_shared<ELikeSlotExactRequirement>(best_eventual_id->slot_key()->value(), false));
+                        part_spec.exact_slot_constraint(best_eventual_id->slot_key()->value(), false);
                         spec = std::make_shared<PackageDepSpec>(part_spec);
                     }
                 }
diff --git a/paludis/resolver/decider.cc b/paludis/resolver/decider.cc
index b0e0dbd..3af2dc5 100644
--- a/paludis/resolver/decider.cc
+++ b/paludis/resolver/decider.cc
@@ -65,10 +65,8 @@
 #include <paludis/filter.hh>
 #include <paludis/match_package.hh>
 #include <paludis/version_requirements.hh>
-#include <paludis/slot_requirement.hh>
 #include <paludis/choice.hh>
 #include <paludis/action.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/package_id.hh>
 #include <paludis/changed_choices.hh>
 #include <paludis/additional_package_dep_spec_requirement.hh>
@@ -1434,27 +1432,6 @@ Decider::find_any_score(
     return std::make_pair(acs_not_installable, operator_bias);
 }
 
-namespace
-{
-    struct SlotNameFinder
-    {
-        std::shared_ptr<SlotName> visit(const SlotExactRequirement & s)
-        {
-            return std::make_shared<SlotName>(s.slot());
-        }
-
-        std::shared_ptr<SlotName> visit(const SlotAnyUnlockedRequirement &)
-        {
-            return make_null_shared_ptr();
-        }
-
-        std::shared_ptr<SlotName> visit(const SlotAnyLockedRequirement &)
-        {
-            return make_null_shared_ptr();
-        }
-    };
-}
-
 const std::shared_ptr<const Resolvents>
 Decider::_get_resolvents_for_blocker(const BlockDepSpec & spec,
         const std::shared_ptr<const Reason> & reason) const
@@ -1462,11 +1439,8 @@ Decider::_get_resolvents_for_blocker(const BlockDepSpec & spec,
     Context context("When finding slots for '" + stringify(spec) + "':");
 
     std::shared_ptr<SlotName> exact_slot;
-    if (spec.blocking().slot_requirement_ptr())
-    {
-        SlotNameFinder f;
-        exact_slot = spec.blocking().slot_requirement_ptr()->accept_returning<std::shared_ptr<SlotName> >(f);
-    }
+    if (spec.blocking().exact_slot_constraint())
+        exact_slot = make_shared_copy(spec.blocking().exact_slot_constraint()->name());
 
     DestinationTypes destination_types(_get_destination_types_for_blocker(spec, reason));
     std::shared_ptr<Resolvents> result(std::make_shared<Resolvents>());
@@ -1507,11 +1481,8 @@ Decider::_get_resolvents_for(
 
     std::shared_ptr<SlotName> exact_slot;
 
-    if (spec.slot_requirement_ptr())
-    {
-        SlotNameFinder f;
-        exact_slot = spec.slot_requirement_ptr()->accept_returning<std::shared_ptr<SlotName> >(f);
-    }
+    if (spec.exact_slot_constraint())
+        exact_slot = make_shared_copy(spec.exact_slot_constraint()->name());
 
     return _imp->fns.get_resolvents_for_fn()(spec, maybe_from_package_id_from_reason(reason), exact_slot, reason);
 }
diff --git a/paludis/resolver/find_replacing_helper.cc b/paludis/resolver/find_replacing_helper.cc
index 88e3155..42906b6 100644
--- a/paludis/resolver/find_replacing_helper.cc
+++ b/paludis/resolver/find_replacing_helper.cc
@@ -25,7 +25,6 @@
 #include <paludis/util/stringify.hh>
 #include <paludis/package_id.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 #include <paludis/repository.hh>
 #include <paludis/environment.hh>
diff --git a/paludis/resolver/get_constraints_for_dependent_helper.cc b/paludis/resolver/get_constraints_for_dependent_helper.cc
index 89ea8b9..b725c58 100644
--- a/paludis/resolver/get_constraints_for_dependent_helper.cc
+++ b/paludis/resolver/get_constraints_for_dependent_helper.cc
@@ -34,7 +34,6 @@
 #include <paludis/package_id.hh>
 #include <paludis/package_dep_spec_collection.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 
 using namespace paludis;
@@ -85,7 +84,7 @@ GetConstraintsForDependentHelper::operator() (
         PartiallyMadePackageDepSpec partial_spec({ });
         partial_spec.package(id->name());
         if (id->slot_key())
-            partial_spec.slot_requirement(std::make_shared<ELikeSlotExactRequirement>(id->slot_key()->value(), false));
+            partial_spec.exact_slot_constraint(id->slot_key()->value(), false);
         spec = std::make_shared<PackageDepSpec>(partial_spec);
     }
 
diff --git a/paludis/resolver/get_constraints_for_purge_helper.cc b/paludis/resolver/get_constraints_for_purge_helper.cc
index c410c78..eef5082 100644
--- a/paludis/resolver/get_constraints_for_purge_helper.cc
+++ b/paludis/resolver/get_constraints_for_purge_helper.cc
@@ -34,7 +34,6 @@
 #include <paludis/package_id.hh>
 #include <paludis/package_dep_spec_collection.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 
 using namespace paludis;
@@ -80,7 +79,7 @@ GetConstraintsForPurgeHelper::operator() (
     PartiallyMadePackageDepSpec partial_spec({ });
     partial_spec.package(id->name());
     if (id->slot_key())
-        partial_spec.slot_requirement(std::make_shared<ELikeSlotExactRequirement>(id->slot_key()->value(), false));
+        partial_spec.exact_slot_constraint(id->slot_key()->value(), false);
     PackageDepSpec spec(partial_spec);
 
     const std::shared_ptr<WasUsedByReason> reason(std::make_shared<WasUsedByReason>(was_used_by_ids));
diff --git a/paludis/resolver/get_destination_types_for_blocker_helper.cc b/paludis/resolver/get_destination_types_for_blocker_helper.cc
index 6a8c80d..6dc2c30 100644
--- a/paludis/resolver/get_destination_types_for_blocker_helper.cc
+++ b/paludis/resolver/get_destination_types_for_blocker_helper.cc
@@ -32,7 +32,6 @@
 #include <paludis/package_id.hh>
 #include <paludis/package_dep_spec_collection.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 
 using namespace paludis;
diff --git a/paludis/resolver/get_destination_types_for_error_helper.cc b/paludis/resolver/get_destination_types_for_error_helper.cc
index efd29b1..a80aefa 100644
--- a/paludis/resolver/get_destination_types_for_error_helper.cc
+++ b/paludis/resolver/get_destination_types_for_error_helper.cc
@@ -32,7 +32,6 @@
 #include <paludis/package_id.hh>
 #include <paludis/package_dep_spec_collection.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 
 using namespace paludis;
diff --git a/paludis/resolver/match_qpns.cc b/paludis/resolver/match_qpns.cc
index 366429c..2af1ee3 100644
--- a/paludis/resolver/match_qpns.cc
+++ b/paludis/resolver/match_qpns.cc
@@ -42,7 +42,9 @@ paludis::resolver::match_qpns(
      * but we're lazy) */
     if (! package_dep_spec_has_properties(spec, make_named_values<PackageDepSpecProperties>(
                     n::has_additional_requirements() = false,
+                    n::has_any_slot_requirement() = false,
                     n::has_category_name_part() = indeterminate,
+                    n::has_exact_slot_requirement() = false,
                     n::has_from_repository() = false,
                     n::has_in_repository() = false,
                     n::has_installable_to_path() = false,
@@ -50,7 +52,6 @@ paludis::resolver::match_qpns(
                     n::has_installed_at_path() = false,
                     n::has_package() = indeterminate,
                     n::has_package_name_part() = indeterminate,
-                    n::has_slot_requirement() = false,
                     n::has_tag() = false,
                     n::has_version_requirements() = false
                     )))
diff --git a/paludis/resolver/resolver_test.cc b/paludis/resolver/resolver_test.cc
index 284ac1d..820f0f7 100644
--- a/paludis/resolver/resolver_test.cc
+++ b/paludis/resolver/resolver_test.cc
@@ -52,7 +52,6 @@
 #include <paludis/filtered_generator.hh>
 #include <paludis/generator.hh>
 #include <paludis/selection.hh>
-#include <paludis/elike_slot_requirement.hh>
 #include <paludis/partially_made_package_dep_spec.hh>
 
 #include <paludis/repositories/fake/fake_installed_repository.hh>
diff --git a/paludis/resolver/sanitised_dependencies.cc b/paludis/resolver/sanitised_dependencies.cc
index ac0921f..d283ab5 100644
--- a/paludis/resolver/sanitised_dependencies.cc
+++ b/paludis/resolver/sanitised_dependencies.cc
@@ -36,7 +36,6 @@
 #include <paludis/util/map.hh>
 #include <paludis/util/accept_visitor.hh>
 #include <paludis/spec_tree.hh>
-#include <paludis/slot_requirement.hh>
 #include <paludis/metadata_key.hh>
 #include <paludis/package_id.hh>
 #include <paludis/elike_package_dep_spec.hh>
diff --git a/paludis/set_file.cc b/paludis/set_file.cc
index 6d1c767..c5dc4c8 100644
--- a/paludis/set_file.cc
+++ b/paludis/set_file.cc
@@ -169,6 +169,18 @@ namespace
         }
     };
 
+    PackageDepSpec name_and_slot(const PackageDepSpec & spec)
+    {
+        if (spec.exact_slot_constraint())
+            return make_package_dep_spec({ })
+                .package(spec.package_name_constraint()->name())
+                .exact_slot_constraint(spec.exact_slot_constraint()->name(), spec.exact_slot_constraint()->locked())
+                ;
+        else
+            return make_package_dep_spec({ })
+                .package(spec.package_name_constraint()->name());
+    }
+
     void
     do_one_conf_line(const std::string & line, std::shared_ptr<SetSpecTree> result,
             const SetFileParams & params)
@@ -269,10 +281,7 @@ namespace
                         Log::get_instance()->message("set_file.bad_operator", ll_warning, lc_context)
                             << "Line '" << line << "' uses ?: operator but no environment is available";
                     else if (! (*params.environment())[selection::SomeArbitraryVersion(generator::Matches(
-                                    make_package_dep_spec({ })
-                                    .package(spec->package_name_constraint()->name())
-                                    .slot_requirement(spec->slot_requirement_ptr()),
-                                    make_null_shared_ptr(), { }) |
+                                    name_and_slot(*spec), make_null_shared_ptr(), { }) |
                                 filter::InstalledAtRoot(params.environment()->preferred_root_key()->value()))]->empty())
                         result->top()->append(spec);
                 }
diff --git a/paludis/slot_requirement-fwd.hh b/paludis/slot_requirement-fwd.hh
deleted file mode 100644
index 09852be..0000000
--- a/paludis/slot_requirement-fwd.hh
+++ /dev/null
@@ -1,36 +0,0 @@
-/* vim: set sw=4 sts=4 et foldmethod=syntax : */
-
-/*
- * Copyright (c) 2008 Ciaran McCreesh
- *
- * This file is part of the Paludis package manager. Paludis is free software;
- * you can redistribute it and/or modify it under the terms of the GNU General
- * Public License version 2, as published by the Free Software Foundation.
- *
- * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#ifndef PALUDIS_GUARD_PALUDIS_SLOT_REQUIREMENT_FWD_HH
-#define PALUDIS_GUARD_PALUDIS_SLOT_REQUIREMENT_FWD_HH 1
-
-#include <iosfwd>
-#include <paludis/util/attributes.hh>
-
-namespace paludis
-{
-    struct SlotRequirement;
-    struct SlotExactRequirement;
-    struct SlotAnyLockedRequirement;
-    struct SlotAnyUnlockedRequirement;
-
-    std::ostream & operator<< (std::ostream &, const SlotRequirement &) PALUDIS_VISIBLE;
-}
-
-#endif
diff --git a/paludis/slot_requirement.cc b/paludis/slot_requirement.cc
deleted file mode 100644
index 97690e7..0000000
--- a/paludis/slot_requirement.cc
+++ /dev/null
@@ -1,31 +0,0 @@
-/* vim: set sw=4 sts=4 et foldmethod=syntax : */
-
-/*
- * Copyright (c) 2008 Ciaran McCreesh
- *
- * This file is part of the Paludis package manager. Paludis is free software;
- * you can redistribute it and/or modify it under the terms of the GNU General
- * Public License version 2, as published by the Free Software Foundation.
- *
- * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#include <paludis/slot_requirement.hh>
-#include <ostream>
-
-using namespace paludis;
-
-std::ostream &
-paludis::operator<< (std::ostream & s, const SlotRequirement & r)
-{
-    s << r.as_string();
-    return s;
-}
-
diff --git a/paludis/slot_requirement.hh b/paludis/slot_requirement.hh
deleted file mode 100644
index d1c3293..0000000
--- a/paludis/slot_requirement.hh
+++ /dev/null
@@ -1,59 +0,0 @@
-/* vim: set sw=4 sts=4 et foldmethod=syntax : */
-
-/*
- * Copyright (c) 2008, 2011 Ciaran McCreesh
- *
- * This file is part of the Paludis package manager. Paludis is free software;
- * you can redistribute it and/or modify it under the terms of the GNU General
- * Public License version 2, as published by the Free Software Foundation.
- *
- * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#ifndef PALUDIS_GUARD_PALUDIS_SLOT_REQUIREMENT_HH
-#define PALUDIS_GUARD_PALUDIS_SLOT_REQUIREMENT_HH 1
-
-#include <paludis/slot_requirement-fwd.hh>
-#include <paludis/name-fwd.hh>
-#include <paludis/util/visitor.hh>
-#include <paludis/util/type_list.hh>
-
-namespace paludis
-{
-    class PALUDIS_VISIBLE SlotRequirement :
-        public virtual DeclareAbstractAcceptMethods<SlotRequirement, MakeTypeList<
-            SlotExactRequirement, SlotAnyLockedRequirement, SlotAnyUnlockedRequirement>::Type>
-    {
-        public:
-            virtual const std::string as_string() const PALUDIS_ATTRIBUTE((warn_unused_result)) = 0;
-    };
-
-    class PALUDIS_VISIBLE SlotExactRequirement :
-        public SlotRequirement,
-        public ImplementAcceptMethods<SlotRequirement, SlotExactRequirement>
-    {
-        public:
-            virtual const SlotName slot() const PALUDIS_ATTRIBUTE((warn_unused_result)) = 0;
-    };
-
-    class PALUDIS_VISIBLE SlotAnyLockedRequirement :
-        public SlotRequirement,
-        public ImplementAcceptMethods<SlotRequirement, SlotAnyLockedRequirement>
-    {
-    };
-
-    class PALUDIS_VISIBLE SlotAnyUnlockedRequirement :
-        public SlotRequirement,
-        public ImplementAcceptMethods<SlotRequirement, SlotAnyUnlockedRequirement>
-    {
-    };
-}
-
-#endif
diff --git a/paludis/user_dep_spec-fwd.hh b/paludis/user_dep_spec-fwd.hh
index 4a8a66d..c31ce08 100644
--- a/paludis/user_dep_spec-fwd.hh
+++ b/paludis/user_dep_spec-fwd.hh
@@ -1,7 +1,7 @@
 /* vim: set sw=4 sts=4 et foldmethod=syntax : */
 
 /*
- * Copyright (c) 2005, 2006, 2007, 2008, 2009 Ciaran McCreesh
+ * Copyright (c) 2005, 2006, 2007, 2008, 2009, 2011 Ciaran McCreesh
  *
  * This file is part of the Paludis package manager. Paludis is free software;
  * you can redistribute it and/or modify it under the terms of the GNU General
@@ -63,8 +63,6 @@ namespace paludis
             ///\}
     };
 
-    struct UserSlotExactRequirement;
-
     struct UserKeyRequirement;
 
     /**
diff --git a/paludis/user_dep_spec.cc b/paludis/user_dep_spec.cc
index f2590cd..c2de828 100644
--- a/paludis/user_dep_spec.cc
+++ b/paludis/user_dep_spec.cc
@@ -245,7 +245,7 @@ namespace
         std::string::size_type slot_p(s.rfind(':'));
         if (std::string::npos != slot_p)
         {
-            result.slot_requirement(std::make_shared<UserSlotExactRequirement>(SlotName(s.substr(slot_p + 1))));
+            result.exact_slot_constraint(SlotName(s.substr(slot_p + 1)), false);
             s.erase(slot_p);
         }
     }
@@ -376,22 +376,6 @@ paludis::envless_parse_package_dep_spec_for_tests(const std::string & ss)
             ));
 }
 
-UserSlotExactRequirement::UserSlotExactRequirement(const SlotName & s) :
-    _s(s)
-{
-}
-const SlotName
-UserSlotExactRequirement::slot() const
-{
-    return _s;
-}
-
-const std::string
-UserSlotExactRequirement::as_string() const
-{
-    return ":" + stringify(_s);
-}
-
 GotASetNotAPackageDepSpec::GotASetNotAPackageDepSpec(const std::string & s) throw () :
     Exception("'" + s + "' is a set, not a package")
 {
diff --git a/paludis/user_dep_spec.hh b/paludis/user_dep_spec.hh
index d426845..6567911 100644
--- a/paludis/user_dep_spec.hh
+++ b/paludis/user_dep_spec.hh
@@ -22,7 +22,6 @@
 
 #include <paludis/user_dep_spec-fwd.hh>
 #include <paludis/dep_spec.hh>
-#include <paludis/slot_requirement.hh>
 #include <paludis/filter.hh>
 #include <paludis/additional_package_dep_spec_requirement.hh>
 #include <paludis/util/pimp.hh>
@@ -53,24 +52,6 @@ namespace paludis
     PackageDepSpec envless_parse_package_dep_spec_for_tests(
             const std::string &) PALUDIS_VISIBLE;
 
-    class PALUDIS_VISIBLE UserSlotExactRequirement :
-        public SlotExactRequirement
-    {
-        private:
-            const SlotName _s;
-
-        public:
-            ///\name Basic operations
-            ///\{
-
-            UserSlotExactRequirement(const SlotName &);
-
-            ///\}
-
-            virtual const SlotName slot() const PALUDIS_ATTRIBUTE((warn_unused_result));
-            virtual const std::string as_string() const PALUDIS_ATTRIBUTE((warn_unused_result));
-    };
-
     /**
      * A key requirement for a user PackageDepSpec.
      *
diff --git a/paludis/user_dep_spec_TEST.cc b/paludis/user_dep_spec_TEST.cc
index b8a69c3..d266be6 100644
--- a/paludis/user_dep_spec_TEST.cc
+++ b/paludis/user_dep_spec_TEST.cc
@@ -127,11 +127,11 @@ UserDepSpecTest::check_spec(
     }
 
     if (slot_requirement.empty())
-        EXPECT_TRUE(! spec.slot_requirement_ptr());
+        EXPECT_TRUE(! spec.exact_slot_constraint());
     else
     {
-        EXPECT_TRUE(bool(spec.slot_requirement_ptr()));
-        EXPECT_EQ(slot_requirement, stringify(*spec.slot_requirement_ptr()));
+        EXPECT_TRUE(bool(spec.exact_slot_constraint()));
+        EXPECT_EQ(slot_requirement, ":" + stringify(spec.exact_slot_constraint()->name()));
     }
 
     if (from_repository.empty())
diff --git a/python/dep_spec.cc b/python/dep_spec.cc
index 5d5ce2f..ab05cfb 100644
--- a/python/dep_spec.cc
+++ b/python/dep_spec.cc
@@ -78,7 +78,8 @@ namespace paludis
         std::shared_ptr<const PackageNamePartConstraint> package_name_part_constraint;
         std::shared_ptr<VersionRequirements> version_requirements;
         VersionRequirementsMode version_requirements_mode;
-        std::shared_ptr<const SlotRequirement> slot;
+        std::shared_ptr<const AnySlotConstraint> any_slot;
+        std::shared_ptr<const ExactSlotConstraint> exact_slot;
         std::shared_ptr<const InRepositoryConstraint> in_repository;
         std::shared_ptr<const FromRepositoryConstraint> from_repository;
         std::shared_ptr<const AdditionalPackageDepSpecRequirements> additional_requirements;
@@ -90,7 +91,8 @@ namespace paludis
                 const std::shared_ptr<const PackageNamePartConstraint> & p,
                 const std::shared_ptr<VersionRequirements> & v,
                 const VersionRequirementsMode m,
-                const std::shared_ptr<const SlotRequirement> & s,
+                const std::shared_ptr<const AnySlotConstraint> & s,
+                const std::shared_ptr<const ExactSlotConstraint> & xs,
                 const std::shared_ptr<const InRepositoryConstraint> & ri,
                 const std::shared_ptr<const FromRepositoryConstraint> & rf,
                 const std::shared_ptr<const AdditionalPackageDepSpecRequirements> & u,
@@ -100,7 +102,8 @@ namespace paludis
             package_name_part_constraint(p),
             version_requirements(v),
             version_requirements_mode(m),
-            slot(s),
+            any_slot(s),
+            exact_slot(xs),
             in_repository(ri),
             from_repository(rf),
             additional_requirements(u),
@@ -228,7 +231,8 @@ PythonPackageDepSpec::PythonPackageDepSpec(const PackageDepSpec & p) :
             p.package_name_part_constraint(),
             std::make_shared<VersionRequirements>(),
             p.version_requirements_mode(),
-            p.slot_requirement_ptr(),
+            p.any_slot_constraint(),
+            p.exact_slot_constraint(),
             p.in_repository_constraint(),
             p.from_repository_constraint(),
             p.additional_requirements_ptr(),
@@ -249,7 +253,8 @@ PythonPackageDepSpec::PythonPackageDepSpec(const PythonPackageDepSpec & p) :
             p.package_name_part_constraint(),
             std::make_shared<VersionRequirements>(),
             p.version_requirements_mode(),
-            p.slot_requirement_ptr(),
+            p.any_slot_constraint(),
+            p.exact_slot_constraint(),
             p.in_repository_constraint(),
             p.from_repository_constraint(),
             p.additional_requirements_ptr(),
@@ -278,8 +283,11 @@ PythonPackageDepSpec::operator PackageDepSpec() const
 
     p.version_requirements_mode(version_requirements_mode());
 
-    if (slot_requirement_ptr())
-        p.slot_requirement(slot_requirement_ptr());
+    if (any_slot_constraint())
+        p.any_slot_constraint(any_slot_constraint()->locking());
+
+    if (exact_slot_constraint())
+        p.exact_slot_constraint(exact_slot_constraint()->name(), exact_slot_constraint()->locked());
 
     if (in_repository_constraint())
         p.in_repository(in_repository_constraint()->name());
@@ -346,10 +354,16 @@ PythonPackageDepSpec::set_version_requirements_mode(const VersionRequirementsMod
     _imp->version_requirements_mode = m;
 }
 
-std::shared_ptr<const SlotRequirement>
-PythonPackageDepSpec::slot_requirement_ptr() const
+const std::shared_ptr<const AnySlotConstraint>
+PythonPackageDepSpec::any_slot_constraint() const
+{
+    return _imp->any_slot;
+}
+
+const std::shared_ptr<const ExactSlotConstraint>
+PythonPackageDepSpec::exact_slot_constraint() const
 {
-    return _imp->slot;
+    return _imp->exact_slot;
 }
 
 const std::shared_ptr<const InRepositoryConstraint>
@@ -1226,12 +1240,15 @@ void expose_dep_spec()
                 "Version requirements mode."
                 )
 
-#if 0
-        .add_property("slot", &PythonPackageDepSpec::slot_ptr,
-                "[ro] SlotName\n"
-                "Slot name (may be None)."
+        .add_property("exact_slot", &PythonPackageDepSpec::exact_slot_constraint,
+                "[ro] ExactSlotConstraint\n"
+                "Exact slot constraint (may be None)."
+                )
+
+        .add_property("any_slot", &PythonPackageDepSpec::any_slot_constraint,
+                "[ro] AnySlotConstraint\n"
+                "Any slot constraint (may be None)."
                 )
-#endif
 
         .add_property("in_repository_constraint", &PythonPackageDepSpec::in_repository_constraint,
                 "[ro] InRepositoryConstraint\n"
diff --git a/python/dep_spec.hh b/python/dep_spec.hh
index 46963ac..d53d4eb 100644
--- a/python/dep_spec.hh
+++ b/python/dep_spec.hh
@@ -177,11 +177,12 @@ namespace paludis
                 const std::shared_ptr<const CategoryNamePartConstraint> category_name_part_constraint() const;
                 const std::shared_ptr<const InRepositoryConstraint> in_repository_constraint() const;
                 const std::shared_ptr<const FromRepositoryConstraint> from_repository_constraint() const;
+                const std::shared_ptr<const ExactSlotConstraint> exact_slot_constraint() const;
+                const std::shared_ptr<const AnySlotConstraint> any_slot_constraint() const;
 
                 std::shared_ptr<const VersionRequirements> version_requirements_ptr() const;
                 VersionRequirementsMode version_requirements_mode() const;
                 void set_version_requirements_mode(const VersionRequirementsMode m);
-                std::shared_ptr<const SlotRequirement> slot_requirement_ptr() const;
                 std::shared_ptr<const AdditionalPackageDepSpecRequirements> additional_requirements_ptr() const;
 
                 std::string py_str() const;
diff --git a/python/package_dep_spec_constraint.cc b/python/package_dep_spec_constraint.cc
index e89f463..c78ba41 100644
--- a/python/package_dep_spec_constraint.cc
+++ b/python/package_dep_spec_constraint.cc
@@ -186,5 +186,39 @@ void expose_package_dep_spec_constraint()
                 "[RO] Whether to include masked, as per ::repo??"
             )
         ;
+
+    /**
+     * AnySlotConstraint
+     */
+    class_package_dep_spec_constraint<AnySlotConstraint>
+        (
+         "AnySlotConstraint",
+         "A :* or := constraint for a PackageDepSpec.",
+         bp::no_init
+        )
+
+        .add_property("locking", &AnySlotConstraint::locking,
+                "[RO] Are we locking (:= rather than :*)?"
+            )
+        ;
+
+    /**
+     * ExactSlotConstraint
+     */
+    class_package_dep_spec_constraint<ExactSlotConstraint>
+        (
+         "ExactSlotConstraint",
+         "A :slot or :=slot constraint for a PackageDepSpec.",
+         bp::no_init
+        )
+
+        .add_property("locked", &ExactSlotConstraint::locked,
+                "[RO] Are we locked (:=blah)?"
+            )
+
+        .add_property("name", &ExactSlotConstraint::name,
+                "[RO] The slot name"
+            )
+        ;
 }
 
diff --git a/ruby/dep_spec.cc b/ruby/dep_spec.cc
index da98fb9..6e6e2a6 100644
--- a/ruby/dep_spec.cc
+++ b/ruby/dep_spec.cc
@@ -67,56 +67,6 @@ namespace
 
     static VALUE c_version_requirements_mode;
 
-    static VALUE c_slot_requirement;
-    static VALUE c_slot_exact_requirement;
-    static VALUE c_slot_any_locked_requirement;
-    static VALUE c_slot_any_unlocked_requirement;
-
-    struct V
-    {
-        VALUE value;
-        std::shared_ptr<const SlotRequirement> mm;
-
-        V(std::shared_ptr<const SlotRequirement> _m) :
-            mm(_m)
-        {
-        }
-
-        void visit(const SlotExactRequirement &)
-        {
-            value = Data_Wrap_Struct(c_slot_exact_requirement, 0, &Common<std::shared_ptr<const SlotRequirement> >::free,
-                    new std::shared_ptr<const SlotRequirement>(mm));
-        }
-
-        void visit(const SlotAnyLockedRequirement &)
-        {
-            value = Data_Wrap_Struct(c_slot_any_locked_requirement, 0, &Common<std::shared_ptr<const SlotRequirement> >::free,
-                    new std::shared_ptr<const SlotRequirement>(mm));
-        }
-
-        void visit(const SlotAnyUnlockedRequirement &)
-        {
-            value = Data_Wrap_Struct(c_slot_any_unlocked_requirement, 0, &Common<std::shared_ptr<const SlotRequirement> >::free,
-                    new std::shared_ptr<const SlotRequirement>(mm));
-        }
-
-    };
-
-    VALUE
-    slot_requirement_to_value(std::shared_ptr<const SlotRequirement> m)
-    {
-        try
-        {
-            V v(m);
-            m->accept(v);
-            return v.value;
-        }
-        catch (const std::exception & e)
-        {
-            exception_to_ruby_exception(e);
-        }
-    }
-
     struct WrappedSpecBase;
     template <typename> struct WrappedSpec;
 
@@ -628,46 +578,62 @@ namespace
 
     /*
      * call-seq:
-     *     text -> String
+     *     any_slot_constraint -> AnySlotConstraint or Nil
      *
-     * Fetch our text.
+     * Fetch the any-slot constraint (may be Nil).
      */
     VALUE
-    string_dep_spec_text(VALUE self)
+    package_dep_spec_any_slot_constraint(VALUE self)
     {
         std::shared_ptr<WrappedSpecBase> * ptr;
         Data_Get_Struct(self, std::shared_ptr<WrappedSpecBase>, ptr);
-        return rb_str_new2(stringify(std::static_pointer_cast<const StringDepSpec>((*ptr)->base_spec())->text()).c_str());
+        if (! bool(std::static_pointer_cast<const WrappedSpec<PackageDepSpec> >(*ptr)->spec()->any_slot_constraint()))
+            return Qnil;
+        return package_dep_spec_constraint_to_value(std::static_pointer_cast<const WrappedSpec<PackageDepSpec> >(*ptr)->spec()->any_slot_constraint());
     }
 
     /*
      * call-seq:
-     *     to_s -> String
+     *     exact_slot_constraint -> ExactSlotConstraint or Nil
      *
-     * Fetch a string representation of ourself.
+     * Fetch the exact-slot constraint (may be Nil).
      */
-    template <typename T_>
-    VALUE dep_spec_to_s(VALUE self)
+    VALUE
+    package_dep_spec_exact_slot_constraint(VALUE self)
     {
         std::shared_ptr<WrappedSpecBase> * ptr;
         Data_Get_Struct(self, std::shared_ptr<WrappedSpecBase>, ptr);
-        return rb_str_new2(stringify(*std::static_pointer_cast<const WrappedSpec<T_> >(*ptr)->spec()).c_str());
+        if (! bool(std::static_pointer_cast<const WrappedSpec<PackageDepSpec> >(*ptr)->spec()->exact_slot_constraint()))
+            return Qnil;
+        return package_dep_spec_constraint_to_value(std::static_pointer_cast<const WrappedSpec<PackageDepSpec> >(*ptr)->spec()->exact_slot_constraint());
     }
 
     /*
      * call-seq:
-     *     slot_requirement -> SlotRequirement or Nil
+     *     text -> String
      *
-     * Fetch the slot requirement.
+     * Fetch our text.
      */
     VALUE
-    package_dep_spec_slot_requirement_ptr(VALUE self)
+    string_dep_spec_text(VALUE self)
     {
         std::shared_ptr<WrappedSpecBase> * ptr;
         Data_Get_Struct(self, std::shared_ptr<WrappedSpecBase>, ptr);
-        if (! bool(std::static_pointer_cast<const WrappedSpec<PackageDepSpec> >(*ptr)->spec()->slot_requirement_ptr()))
-            return Qnil;
-        return slot_requirement_to_value(std::static_pointer_cast<const WrappedSpec<PackageDepSpec> >(*ptr)->spec()->slot_requirement_ptr());
+        return rb_str_new2(stringify(std::static_pointer_cast<const StringDepSpec>((*ptr)->base_spec())->text()).c_str());
+    }
+
+    /*
+     * call-seq:
+     *     to_s -> String
+     *
+     * Fetch a string representation of ourself.
+     */
+    template <typename T_>
+    VALUE dep_spec_to_s(VALUE self)
+    {
+        std::shared_ptr<WrappedSpecBase> * ptr;
+        Data_Get_Struct(self, std::shared_ptr<WrappedSpecBase>, ptr);
+        return rb_str_new2(stringify(*std::static_pointer_cast<const WrappedSpec<T_> >(*ptr)->spec()).c_str());
     }
 
     /*
@@ -958,14 +924,6 @@ namespace
 
     }
 
-    VALUE
-    slot_exact_requirement_slot(VALUE self)
-    {
-        std::shared_ptr<const SlotExactRequirement> * ptr;
-        Data_Get_Struct(self, std::shared_ptr<const SlotExactRequirement>, ptr);
-        return rb_str_new2(stringify((*ptr)->slot()).c_str());
-    }
-
     void do_register_dep_spec()
     {
         /*
@@ -1103,12 +1061,13 @@ namespace
         rb_define_method(c_package_dep_spec, "package_name_constraint", RUBY_FUNC_CAST(&package_dep_spec_package_name_constraint), 0);
         rb_define_method(c_package_dep_spec, "package_name_part_constraint", RUBY_FUNC_CAST(&package_dep_spec_package_name_part_constraint), 0);
         rb_define_method(c_package_dep_spec, "category_name_part_constraint", RUBY_FUNC_CAST(&package_dep_spec_category_name_part_constraint), 0);
-        rb_define_method(c_package_dep_spec, "slot_requirement", RUBY_FUNC_CAST(&package_dep_spec_slot_requirement_ptr), 0);
         rb_define_method(c_package_dep_spec, "in_repository_constraint", RUBY_FUNC_CAST(&package_dep_spec_in_repository_constraint), 0);
         rb_define_method(c_package_dep_spec, "from_repository_constraint", RUBY_FUNC_CAST(&package_dep_spec_from_repository_constraint), 0);
         rb_define_method(c_package_dep_spec, "installable_to_repository_constraint", RUBY_FUNC_CAST(&package_dep_spec_installable_to_repository_constraint), 0);
         rb_define_method(c_package_dep_spec, "installed_at_path_constraint", RUBY_FUNC_CAST(&package_dep_spec_installed_at_path_constraint), 0);
         rb_define_method(c_package_dep_spec, "installable_to_path_constraint", RUBY_FUNC_CAST(&package_dep_spec_installable_to_path_constraint), 0);
+        rb_define_method(c_package_dep_spec, "any_slot_constraint", RUBY_FUNC_CAST(&package_dep_spec_any_slot_constraint), 0);
+        rb_define_method(c_package_dep_spec, "exact_slot_constraint", RUBY_FUNC_CAST(&package_dep_spec_exact_slot_constraint), 0);
         rb_define_method(c_package_dep_spec, "version_requirements", RUBY_FUNC_CAST(&package_dep_spec_version_requirements_ptr), 0);
         rb_define_method(c_package_dep_spec, "version_requirements_mode", RUBY_FUNC_CAST(&package_dep_spec_version_requirements_mode), 0);
 #ifdef CIARANM_REMOVED_THIS
@@ -1190,38 +1149,6 @@ namespace
         // cc_enum_special<paludis/version_requirements.hh, VersionRequirementsMode, c_version_requirements_mode>
 
         rb_define_module_function(paludis_module(), "parse_user_package_dep_spec", RUBY_FUNC_CAST(&paludis_parse_user_dep_spec), -1);
-
-        /*
-         * Document-class: Paludis::SlotRequirement
-         *
-         * A SlotRequirement
-         */
-        c_slot_requirement = rb_define_class_under(paludis_module(), "SlotRequirement", rb_cObject);
-        rb_funcall(c_slot_requirement, rb_intern("private_class_method"), 1, rb_str_new2("new"));
-        rb_define_method(c_slot_requirement, "as_string", RUBY_FUNC_CAST(&Common<std::shared_ptr<const SlotRequirement> >::to_s_via_ptr), 0);
-        rb_define_method(c_slot_requirement, "to_s", RUBY_FUNC_CAST(&Common<std::shared_ptr<const SlotRequirement> >::to_s_via_ptr), 0);
-
-        /*
-         * Document-class: Paludis::ExactSlotRequirement
-         *
-         * An exact slot requiremet (:)
-         */
-        c_slot_exact_requirement = rb_define_class_under(paludis_module(), "SlotExactRequirement", c_slot_requirement);
-        rb_define_method(c_slot_exact_requirement, "slot", RUBY_FUNC_CAST(&slot_exact_requirement_slot), 0);
-
-        /*
-         * Document-class: Paludis::SlotAnyLockedRequirement
-         *
-         * An any locked slot requiremet (:=)
-         */
-        c_slot_any_locked_requirement = rb_define_class_under(paludis_module(), "SlotAnyLockedRequirement", c_slot_requirement);
-
-        /*
-         * Document-class: Paludis::ExactSlotRequirement
-         *
-         * An any unlocked slot requiremet (:*)
-         */
-        c_slot_any_unlocked_requirement = rb_define_class_under(paludis_module(), "SlotAnyUnlockedRequirement", c_slot_requirement);
     }
 }
 
diff --git a/ruby/dep_spec_TEST.rb b/ruby/dep_spec_TEST.rb
index 7e3db1b..d0d63e3 100644
--- a/ruby/dep_spec_TEST.rb
+++ b/ruby/dep_spec_TEST.rb
@@ -130,13 +130,11 @@ module Paludis
         end
 
         def test_slot
-            assert_kind_of SlotExactRequirement, pda.slot_requirement
-            assert_equal ":100", pda.slot_requirement.to_s
-            assert_equal "100", pda.slot_requirement.slot
-            assert_nil pdb.slot_requirement
-            assert_nil pdc.slot_requirement
-            assert_nil pdd.slot_requirement
-            assert_nil pde.slot_requirement
+            assert_equal "100", pda.exact_slot_constraint.name
+            assert_nil pdb.exact_slot_constraint
+            assert_nil pdc.exact_slot_constraint
+            assert_nil pdd.exact_slot_constraint
+            assert_nil pde.exact_slot_constraint
         end
 
         def test_package
diff --git a/ruby/package_dep_spec_constraint.cc b/ruby/package_dep_spec_constraint.cc
index 4d4ed38..6279908 100644
--- a/ruby/package_dep_spec_constraint.cc
+++ b/ruby/package_dep_spec_constraint.cc
@@ -39,6 +39,8 @@ namespace
     static VALUE c_installed_at_path_constraint;
     static VALUE c_installable_to_path_constraint;
     static VALUE c_installable_to_repository_constraint;
+    static VALUE c_any_slot_constraint;
+    static VALUE c_exact_slot_constraint;
 
     struct V
     {
@@ -97,6 +99,18 @@ namespace
             value = Data_Wrap_Struct(c_installable_to_repository_constraint, 0, &Common<std::shared_ptr<const PackageDepSpecConstraint> >::free,
                     new std::shared_ptr<const PackageDepSpecConstraint>(mm));
         }
+
+        void visit(const AnySlotConstraint &)
+        {
+            value = Data_Wrap_Struct(c_any_slot_constraint, 0, &Common<std::shared_ptr<const PackageDepSpecConstraint> >::free,
+                    new std::shared_ptr<const PackageDepSpecConstraint>(mm));
+        }
+
+        void visit(const ExactSlotConstraint &)
+        {
+            value = Data_Wrap_Struct(c_exact_slot_constraint, 0, &Common<std::shared_ptr<const PackageDepSpecConstraint> >::free,
+                    new std::shared_ptr<const PackageDepSpecConstraint>(mm));
+        }
     };
 
     /*
@@ -229,6 +243,45 @@ namespace
         return (std::static_pointer_cast<const InstallableToRepositoryConstraint>(*ptr))->include_masked() ? Qtrue : Qfalse;
     }
 
+    /*
+     * Document-method: locking?
+     *
+     * The locking constraint.
+     */
+    static VALUE
+    any_slot_constraint_locking(VALUE self)
+    {
+        std::shared_ptr<const PackageDepSpecConstraint> * ptr;
+        Data_Get_Struct(self, std::shared_ptr<const PackageDepSpecConstraint>, ptr);
+        return (std::static_pointer_cast<const AnySlotConstraint>(*ptr))->locking() ? Qtrue : Qfalse;
+    }
+
+    /*
+     * Document-method: locked?
+     *
+     * The locked constraint.
+     */
+    static VALUE
+    exact_slot_constraint_locked(VALUE self)
+    {
+        std::shared_ptr<const PackageDepSpecConstraint> * ptr;
+        Data_Get_Struct(self, std::shared_ptr<const PackageDepSpecConstraint>, ptr);
+        return (std::static_pointer_cast<const ExactSlotConstraint>(*ptr))->locked() ? Qtrue : Qfalse;
+    }
+
+    /*
+     * Document-method: name
+     *
+     * The name constraint.
+     */
+    static VALUE
+    exact_slot_constraint_name(VALUE self)
+    {
+        std::shared_ptr<const PackageDepSpecConstraint> * ptr;
+        Data_Get_Struct(self, std::shared_ptr<const PackageDepSpecConstraint>, ptr);
+        return rb_str_new2(stringify((std::static_pointer_cast<const ExactSlotConstraint>(*ptr))->name()).c_str());
+    }
+
     void do_register_package_dep_spec_constraint()
     {
         /*
@@ -329,6 +382,30 @@ namespace
                     &installable_to_repository_constraint_name), 0);
         rb_define_method(c_installable_to_repository_constraint, "include_masked?", RUBY_FUNC_CAST(
                     &installable_to_repository_constraint_include_masked), 0);
+
+        /*
+         * Document-class: Paludis::AnySlotConstraint
+         *
+         * Represents a :* or := constraint in a PackageDepSpec.
+         */
+        c_any_slot_constraint = rb_define_class_under(
+                paludis_module(), "AnySlotConstraint", c_package_dep_spec_constraint);
+        rb_funcall(c_any_slot_constraint, rb_intern("private_class_method"), 1, rb_str_new2("new"));
+        rb_define_method(c_any_slot_constraint, "locking?", RUBY_FUNC_CAST(
+                    &any_slot_constraint_locking), 0);
+
+        /*
+         * Document-class: Paludis::ExactSlotConstraint
+         *
+         * Represents a :slot or :=slot constraint in a PackageDepSpec.
+         */
+        c_exact_slot_constraint = rb_define_class_under(
+                paludis_module(), "ExactSlotConstraint", c_package_dep_spec_constraint);
+        rb_funcall(c_exact_slot_constraint, rb_intern("private_class_method"), 1, rb_str_new2("new"));
+        rb_define_method(c_exact_slot_constraint, "locked?", RUBY_FUNC_CAST(
+                    &exact_slot_constraint_locked), 0);
+        rb_define_method(c_exact_slot_constraint, "name", RUBY_FUNC_CAST(
+                    &exact_slot_constraint_name), 0);
     }
 }
 
diff --git a/src/clients/cave/cmd_execute_resolution.cc b/src/clients/cave/cmd_execute_resolution.cc
index 895be31..d72dc11 100644
--- a/src/clients/cave/cmd_execute_resolution.cc
+++ b/src/clients/cave/cmd_execute_resolution.cc
@@ -686,7 +686,9 @@ namespace
                 PackageDepSpec spec(parse_user_package_dep_spec(std::get<2>(p), env.get(), { updso_no_disambiguation }));
                 if (package_dep_spec_has_properties(spec, make_named_values<PackageDepSpecProperties>(
                                 n::has_additional_requirements() = false,
+                                n::has_any_slot_requirement() = false,
                                 n::has_category_name_part() = false,
+                                n::has_exact_slot_requirement() = false,
                                 n::has_from_repository() = false,
                                 n::has_in_repository() = false,
                                 n::has_installable_to_path() = false,
@@ -694,7 +696,6 @@ namespace
                                 n::has_installed_at_path() = false,
                                 n::has_package() = true,
                                 n::has_package_name_part() = false,
-                                n::has_slot_requirement() = false,
                                 n::has_tag() = indeterminate,
                                 n::has_version_requirements() = false
                                 )))
diff --git a/src/clients/cave/cmd_fix_linkage.cc b/src/clients/cave/cmd_fix_linkage.cc
index 1c90472..a99f227 100644
--- a/src/clients/cave/cmd_fix_linkage.cc
+++ b/src/clients/cave/cmd_fix_linkage.cc
@@ -210,7 +210,7 @@ FixLinkageCommand::run(
         PartiallyMadePackageDepSpec part_spec({ });
         part_spec.package((*pkg_it)->name());
         if ((*pkg_it)->slot_key())
-            part_spec.slot_requirement(std::make_shared<UserSlotExactRequirement>((*pkg_it)->slot_key()->value()));
+            part_spec.exact_slot_constraint((*pkg_it)->slot_key()->value(), false);
 
         if (cmdline.a_exact.specified())
             part_spec.version_requirement(make_named_values<VersionRequirement>(
diff --git a/src/clients/cave/cmd_graph_jobs.cc b/src/clients/cave/cmd_graph_jobs.cc
index b573f28..ff47d99 100644
--- a/src/clients/cave/cmd_graph_jobs.cc
+++ b/src/clients/cave/cmd_graph_jobs.cc
@@ -96,8 +96,8 @@ namespace
         else
         {
             std::string result(stringify(p.package_name_constraint()->name().package()));
-            if (p.slot_requirement_ptr())
-                result = result + stringify(*p.slot_requirement_ptr());
+            if (p.exact_slot_constraint())
+                result = result + ":" + stringify(p.exact_slot_constraint()->name());
             if (p.in_repository_constraint())
                 result = result + "::" + stringify(p.in_repository_constraint()->name());
             return result;
diff --git a/src/clients/cave/cmd_print_spec.cc b/src/clients/cave/cmd_print_spec.cc
index e861e49..a693bcf 100644
--- a/src/clients/cave/cmd_print_spec.cc
+++ b/src/clients/cave/cmd_print_spec.cc
@@ -131,9 +131,15 @@ namespace
         if (cmdline.a_slot_requirement.specified())
         {
             if (cmdline.a_slot_requirement.argument().empty())
-                s.clear_slot_requirement();
+            {
+                s.clear_any_slot();
+                s.clear_exact_slot();
+            }
             else
-                s.slot_requirement(std::make_shared<UserSlotExactRequirement>(SlotName(cmdline.a_slot_requirement.argument())));
+            {
+                s.clear_any_slot();
+                s.exact_slot_constraint(SlotName(cmdline.a_slot_requirement.argument()), false);
+            }
         }
 
         if (cmdline.a_in_repository.specified())