From 18d244dd9f26e8306f9e6563fd9a92c468758de3 Mon Sep 17 00:00:00 2001
From: rbock <rbock@eudoxos.de>
Date: Wed, 9 Apr 2014 07:25:24 +0200
Subject: [PATCH] Moved from-methods to from-classes

---
 include/sqlpp11/select.h       | 24 +-------------------
 include/sqlpp11/vendor/from.h  | 40 +++++++++++++++++++++++++++++-----
 include/sqlpp11/vendor/where.h |  1 +
 3 files changed, 36 insertions(+), 29 deletions(-)

diff --git a/include/sqlpp11/select.h b/include/sqlpp11/select.h
index e950e84f..1523bf7c 100644
--- a/include/sqlpp11/select.h
+++ b/include/sqlpp11/select.h
@@ -131,6 +131,7 @@ namespace sqlpp
 				>
 		struct select_t: public detail::select_helper_t<ColumnList, From>::_value_type::template expression_operators<select_t<Database, FlagList, ColumnList, From, Where, GroupBy, Having, OrderBy, Limit, Offset>>,
 		FlagList::template _methods_t<detail::select_policies_t<Database, FlagList, ColumnList, From, Where, GroupBy, Having, OrderBy, Limit, Offset>>,
+		From::template _methods_t<detail::select_policies_t<Database, FlagList, ColumnList, From, Where, GroupBy, Having, OrderBy, Limit, Offset>>,
 		Where::template _methods_t<detail::select_policies_t<Database, FlagList, ColumnList, From, Where, GroupBy, Having, OrderBy, Limit, Offset>>,
 		GroupBy::template _methods_t<detail::select_policies_t<Database, FlagList, ColumnList, From, Where, GroupBy, Having, OrderBy, Limit, Offset>>,
 		Having::template _methods_t<detail::select_policies_t<Database, FlagList, ColumnList, From, Where, GroupBy, Having, OrderBy, Limit, Offset>>,
@@ -206,21 +207,6 @@ namespace sqlpp
 					return { *this, vendor::select_column_list_t<_database_t, Args...>{args...} };
 				}
 
-			template<typename... Args>
-				auto from(Args... args)
-				-> _policies_update_t<vendor::no_from_t, vendor::from_t<void, Args...>>
-				{
-					return { *this, vendor::from_t<void, Args...>{args...} };
-				}
-
-			template<typename... Args>
-				auto dynamic_from(Args... args)
-				-> _policies_update_t<vendor::no_from_t, vendor::from_t<_database_t, Args...>>
-				{
-					static_assert(not std::is_same<_database_t, void>::value, "dynamic_from must not be called in a static statement");
-					return { *this, vendor::from_t<_database_t, Args...>{args...} };
-				}
-
 			// value adding methods
 			template<typename... Args>
 				void add_column(Args... args)
@@ -230,14 +216,6 @@ namespace sqlpp
 					return _column_list.add_column(*this, args...);
 				}
 
-			template<typename... Args>
-				void add_from(Args... args)
-				{
-					static_assert(is_from_t<From>::value, "cannot call add_from() before dynamic_from()");
-					static_assert(is_dynamic_t<From>::value, "cannot call add_using() before dynamic_from()");
-					return _from.add_from(*this, args...);
-				}
-
 			// PseudoTable
 			template<typename AliasProvider>
 				struct _pseudo_table_t
diff --git a/include/sqlpp11/vendor/from.h b/include/sqlpp11/vendor/from.h
index e703b2b3..72a66980 100644
--- a/include/sqlpp11/vendor/from.h
+++ b/include/sqlpp11/vendor/from.h
@@ -64,13 +64,17 @@ namespace sqlpp
 				from_t& operator=(from_t&&) = default;
 				~from_t() = default;
 
-				template<typename Select, typename Table>
-					void add_from(const Select&, Table table)
+				template<typename Policies>
+					struct _methods_t
 					{
-						static_assert(_is_dynamic::value, "add_from can only be called for dynamic_from");
-						static_assert(is_table_t<Table>::value, "from arguments require to be tables or joins");
-						_dynamic_tables.emplace_back(table);
-					}
+						template<typename Table>
+							void add_from(Table table)
+							{
+								static_assert(is_table_t<Table>::value, "invalid expression argument in add_from()");
+#warning: Need to dispatch to actual add method to prevent error messages from being generated
+								return static_cast<typename Policies::_select_t*>(this)->_from._dynamic_tables.emplace_back(table);
+							}
+					};
 
 				std::tuple<Tables...> _tables;
 				vendor::interpretable_list_t<Database> _dynamic_tables;
@@ -79,6 +83,30 @@ namespace sqlpp
 		struct no_from_t
 		{
 			using _is_noop = std::true_type;
+			using _table_set = ::sqlpp::detail::type_set<>;
+
+			template<typename Policies>
+				struct _methods_t
+				{
+					using _database_t = typename Policies::_database_t;
+					template<typename T>
+					using _new_select_t = typename Policies::template _policies_update_t<no_from_t, T>;
+
+					template<typename... Args>
+						auto from(Args... args)
+						-> _new_select_t<from_t<void, Args...>>
+						{
+							return { *static_cast<typename Policies::_select_t*>(this), from_t<void, Args...>{args...} };
+						}
+
+					template<typename... Args>
+						auto dynamic_from(Args... args)
+						-> _new_select_t<from_t<_database_t, Args...>>
+						{
+							static_assert(not std::is_same<_database_t, void>::value, "dynamic_from must not be called in a static statement");
+							return { *static_cast<typename Policies::_select_t*>(this), vendor::from_t<_database_t, Args...>{args...} };
+						}
+				};
 		};
 
 		// Interpreters
diff --git a/include/sqlpp11/vendor/where.h b/include/sqlpp11/vendor/where.h
index 55f7a150..d7ddabeb 100644
--- a/include/sqlpp11/vendor/where.h
+++ b/include/sqlpp11/vendor/where.h
@@ -70,6 +70,7 @@ namespace sqlpp
 						template<typename Expression>
 							void add_where(Expression expression)
 							{
+								static_assert(_is_dynamic::value, "add_where can only be called for dynamic_where");
 								static_assert(is_expression_t<Expression>::value, "invalid expression argument in add_where()");
 #warning: Need to dispatch to actual add method to prevent error messages from being generated
 								return static_cast<typename Policies::_select_t*>(this)->_where._dynamic_expressions.emplace_back(expression);