From ad1c5f94bbbd46c93306db16b87a0ee2fbe6c45b Mon Sep 17 00:00:00 2001
From: rbock <rbock@eudoxos.de>
Date: Tue, 12 Aug 2014 18:48:50 +0200
Subject: [PATCH] Made boolean expression more usable

---
 include/sqlpp11/boolean_expression.h | 31 ++++++++++++++--------------
 tests/BooleanExpressionTest.cpp      |  4 +++-
 tests/InterpretTest.cpp              | 16 ++++++++------
 3 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/include/sqlpp11/boolean_expression.h b/include/sqlpp11/boolean_expression.h
index b2c66acc..5463f94f 100644
--- a/include/sqlpp11/boolean_expression.h
+++ b/include/sqlpp11/boolean_expression.h
@@ -33,17 +33,17 @@
 namespace sqlpp
 {
 	template<typename Database>
-		struct boolean_expression_t
+		struct boolean_expression_t: public boolean::template expression_operators<boolean_expression_t<Database>>
 		{
 			using _traits = make_traits<boolean, tag::is_expression>;
 			using _recursive_traits = make_recursive_traits<>;
 
-			template<typename Expression>
-			boolean_expression_t(Expression expression):
-				_expression(expression)
+			template<typename Expr>
+			boolean_expression_t(Expr expr):
+				_expr(expr)
 			{
-				static_assert(is_expression_t<Expression>::value, "boolean_expression requires a boolean expression argument");
-				static_assert(is_boolean_t<Expression>::value, "boolean_expression requires a boolean expression argument");
+				static_assert(is_expression_t<Expr>::value, "boolean_expression requires a boolean expression argument");
+				static_assert(is_boolean_t<Expr>::value, "boolean_expression requires a boolean expression argument");
 			}
 
 			boolean_expression_t(const boolean_expression_t&) = default;
@@ -52,19 +52,20 @@ namespace sqlpp
 			boolean_expression_t& operator=(boolean_expression_t&&) = default;
 			~boolean_expression_t() = default;
 
-			interpretable_t<Database> _expression;
+			interpretable_t<Database> _expr;
 		};
 
-	template<typename Database, typename T>
-		boolean_expression_t<Database> boolean_expression(const Database&, T t)
-		{
-			return {t};
-		}
-
 	template<typename Database, typename T>
 		boolean_expression_t<Database> boolean_expression(T t)
 		{
-			return {t};
+			using Expr = wrap_operand_t<T>;
+			return {Expr{t}};
+		}
+
+	template<typename Database, typename T>
+		boolean_expression_t<Database> boolean_expression(const Database&, T t)
+		{
+			return boolean_expression<Database>(t);
 		}
 
 	template<typename Context, typename Database>
@@ -74,7 +75,7 @@ namespace sqlpp
 
 			static Context& _(const T& t, Context& context)
 			{
-				return serialize(t._expression);
+				return serialize(t._expr, context);
 			}
 		};
 
diff --git a/tests/BooleanExpressionTest.cpp b/tests/BooleanExpressionTest.cpp
index 3eaf8544..6f0892b9 100644
--- a/tests/BooleanExpressionTest.cpp
+++ b/tests/BooleanExpressionTest.cpp
@@ -35,8 +35,10 @@ int main()
 	test::TabBar t; 
 
 	auto x = boolean_expression(db, t.alpha == 7);
-	x = boolean_expression(db, t.gamma);
 	x = sqlpp::boolean_expression<MockDb>(t.beta.like("%cheesecake"));
+	x = x and boolean_expression(db, t.gamma);
+
+	db(select(t.alpha).from(t).where(x));
 
 	return 0;
 }
diff --git a/tests/InterpretTest.cpp b/tests/InterpretTest.cpp
index 13209e46..6d0943ac 100644
--- a/tests/InterpretTest.cpp
+++ b/tests/InterpretTest.cpp
@@ -25,12 +25,7 @@
 
 #include "Sample.h"
 #include "MockDb.h"
-#include <sqlpp11/alias_provider.h>
-#include <sqlpp11/insert.h>
-#include <sqlpp11/select.h>
-#include <sqlpp11/update.h>
-#include <sqlpp11/remove.h>
-#include <sqlpp11/functions.h>
+#include <sqlpp11/sqlpp11.h>
 
 #include <iostream>
 
@@ -177,5 +172,14 @@ int main()
 
 	flatten(t.alpha == 7, db);
 
+	auto x = boolean_expression(db, t.alpha == 7);
+	x = sqlpp::boolean_expression<MockDb>(t.beta.like("%cheesecake"));
+	x = x and boolean_expression(db, t.gamma);
+	std::cerr << "----------------------------" << std::endl;
+	printer.reset();
+	std::cerr << serialize(x, printer).str() << std::endl;
+
+
+
 	return 0;
 }