More function tests and a few corrections for names and return types

database_api/api.h

@@ -69,6 +69,8 @@ namespace sqlpp
 			static constexpr bool _supports_exists = true;
 			static constexpr bool _supports_like = true;
 			static constexpr bool _supports_in = true;
+			static constexpr bool _supports_is_null = true;
+			static constexpr bool _supports_is_not_null = true;
 			static constexpr bool _supports_max = true;
 			static constexpr bool _supports_min = true;
 			static constexpr bool _supports_not_in = true;

include/sqlpp11/any.h

@@ -42,7 +42,7 @@ namespace sqlpp
 
 			struct _value_type: public Select::_value_type::_base_value_type
 			{
-				using _is_named_expression = std::true_type;
+				using _is_nameless_expression = std::true_type; // must not be named
 			};
 
 			struct _name_t

include/sqlpp11/detail/basic_operators.h

@@ -31,6 +31,7 @@
 #include <sqlpp11/alias.h>
 #include <sqlpp11/sort_order.h>
 #include <sqlpp11/in.h>
+#include <sqlpp11/is_null.h>
 
 namespace sqlpp
 {
@@ -64,12 +65,6 @@ namespace sqlpp
 			static constexpr const char* _name = ">";
 		};
 
-		struct is_null_
-		{
-			using _value_type = boolean;
-			static constexpr const char* _name = "IS NULL";
-		};
-
 		struct is_not_null_
 		{
 			using _value_type = boolean;
@@ -116,12 +111,12 @@ namespace sqlpp
 					return { *static_cast<const Base*>(this), std::forward<T>(t) };
 				}
 
-			null_expression_t<Base, is_null_> is_null() const
+			is_null_t<true, boolean, Base> is_null() const
 			{
 				return { *static_cast<const Base*>(this) };
 			}
 
-			null_expression_t<Base, is_not_null_> is_not_null() const
+			is_null_t<false, boolean, Base> is_not_null() const
 			{
 				return { *static_cast<const Base*>(this) };
 			}
@@ -152,6 +147,7 @@ namespace sqlpp
 			template<typename alias_provider>
 				expression_alias_t<Base, typename std::decay<alias_provider>::type> as(alias_provider&&)
 				{
+					static_assert(not is_nameless_expression_t<Base>::value, "expression cannot have a name, e.g. like any()");
 					return { *static_cast<const Base*>(this) };
 				}
 

include/sqlpp11/expression.h

@@ -175,39 +175,6 @@ namespace sqlpp
 			Lhs _lhs;
 		};
 
-	template<typename Lhs, typename O>
-		struct null_expression_t: public O::_value_type::template operators<null_expression_t<Lhs, O>>
-		{
-			using _value_type = typename O::_value_type;
-
-			null_expression_t(Lhs&& l):
-				_lhs(std::move(l))
-			{}
-
-			null_expression_t(const Lhs& l):
-				_lhs(l)
-			{}
-
-			null_expression_t(const null_expression_t&) = default;
-			null_expression_t(null_expression_t&&) = default;
-			null_expression_t& operator=(const null_expression_t&) = default;
-			null_expression_t& operator=(null_expression_t&&) = default;
-			~null_expression_t() = default;
-
-			template<typename Db>
-				void serialize(std::ostream& os, Db& db) const
-				{
-					os << "(";
-					_lhs.serialize(os, db);
-					os << " ";
-					os << O::_name;
-					os << ")";
-				}
-
-		private:
-			Lhs _lhs;
-		};
-
 	template<typename Lhs, typename O, typename Rhs>
 		struct binary_expression_t: public O::_value_type::template operators<binary_expression_t<Lhs, O, Rhs>>
 		{

include/sqlpp11/in.h

@@ -77,7 +77,7 @@ namespace sqlpp
 				void serialize(std::ostream& os, Db& db) const
 				{
 					static_assert(NotInverted and Db::_supports_in
-							or _inverted and Db::_supports_not_in, "in() not supported by current database");
+							or _inverted and Db::_supports_not_in, "in() and/or not_in() not supported by current database");
 					_operand.serialize(os, db);
 					os << (_inverted ? " NOT IN(" : " IN(");
 					detail::serialize_tuple(os, db, _args, ',');

include/sqlpp11/is_null.h

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2013, Roland Bock
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ * 
+ *   Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ * 
+ *   Redistributions in binary form must reproduce the above copyright notice, this
+ *   list of conditions and the following disclaimer in the documentation and/or
+ *   other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef SQLPP_IS_NULL_H
+#define SQLPP_IS_NULL_H
+
+#include <sstream>
+#include <sqlpp11/type_traits.h>
+#include <sqlpp11/detail/set.h>
+
+namespace sqlpp
+{
+	namespace detail
+	{
+		// The ValueType should be boolean, this is a hack because boolean is not fully defined when the compiler first gets here...
+		template<bool NotInverted, typename ValueType, typename Operand>
+		struct is_null_t: public ValueType::_base_value_type::template operators<is_null_t<NotInverted, ValueType, Operand>>
+		{
+			static constexpr bool _inverted = not NotInverted;
+
+			struct _value_type: public ValueType::_base_value_type // we requite fully defined boolean here
+			{
+				using _is_named_expression = std::true_type;
+			};
+
+			struct _name_t
+			{
+				static constexpr const char* _get_name() { return _inverted ? "IS NOT NULL" : "IS NULL"; }
+				template<typename T>
+					struct _member_t
+					{
+						T in;
+					};
+			};
+
+			is_null_t(const Operand& operand):
+				_operand(operand)
+			{}
+
+			is_null_t(Operand&& operand):
+				_operand(std::move(operand))
+			{}
+
+			is_null_t(const is_null_t&) = default;
+			is_null_t(is_null_t&&) = default;
+			is_null_t& operator=(const is_null_t&) = default;
+			is_null_t& operator=(is_null_t&&) = default;
+			~is_null_t() = default;
+
+			template<typename Db>
+				void serialize(std::ostream& os, Db& db) const
+				{
+					static_assert(NotInverted and Db::_supports_is_null
+							or _inverted and Db::_supports_is_not_null, "is_null() and/or is_not_null() not supported by current database");
+					_operand.serialize(os, db);
+					os << (_inverted ? " IS NOT NULL" : " IS NULL");
+				}
+
+		private:
+			Operand _operand;
+		};
+	}
+}
+
+#endif

include/sqlpp11/some.h

@@ -42,7 +42,7 @@ namespace sqlpp
 
 			struct _value_type: public Select::_value_type::_base_value_type
 			{
-				using _is_named_expression = std::true_type;
+				using _is_nameless_expression = std::true_type; // must not be named
 			};
 
 			struct _name_t

include/sqlpp11/type_traits.h

@@ -84,6 +84,7 @@ namespace sqlpp
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(value);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(expression);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(named_expression);
+	SQLPP_IS_VALUE_TRAIT_GENERATOR(nameless_expression);
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(alias); // FIXME: Is this really part of the value?
 	SQLPP_IS_VALUE_TRAIT_GENERATOR(select_flag);
 

tests/FunctionTest.cpp

@@ -46,12 +46,15 @@ int main()
 		using TI = decltype(t.alpha.in(1, 2, 3));
 		using TF = decltype(f.omega.in(1.0, 2.0, 3.0));
 		using TT = decltype(t.beta.in("a", "b", "c"));
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TT>::value, "type requirement");
@@ -62,12 +65,15 @@ int main()
 		using TI = decltype(t.alpha.not_in(1, 2, 3));
 		using TF = decltype(f.omega.not_in(1.0, 2.0, 3.0));
 		using TT = decltype(t.beta.not_in("a", "b", "c"));
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TT>::value, "type requirement");
@@ -76,6 +82,45 @@ int main()
 	// Test like
 	{
 		using TT = decltype(t.beta.like("%c%"));
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_text_t<TT>::value, "type requirement");
+	}
+
+	// Test is_null
+	{
+		using TI = decltype(t.alpha.is_null());
+		using TF = decltype(f.omega.is_null());
+		using TT = decltype(t.beta.is_null());
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TI>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TI>::value, "type requirement");
+		static_assert(not sqlpp::is_text_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_text_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_text_t<TT>::value, "type requirement");
+	}
+
+	// Test is_not_null
+	{
+		using TI = decltype(t.alpha.is_not_null());
+		using TF = decltype(f.omega.is_not_null());
+		using TT = decltype(t.beta.is_not_null());
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TI>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TI>::value, "type requirement");
+		static_assert(not sqlpp::is_text_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_text_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TT>::value, "type requirement");
@@ -88,9 +133,11 @@ int main()
 	{
 		using TI = decltype(exists(select(t.alpha).from(t)));
 		using TT = decltype(exists(select(t.beta).from(t)));
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
 		static_assert(sqlpp::is_boolean_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TT>::value, "type requirement");
@@ -101,12 +148,18 @@ int main()
 		using TI = decltype(any(select(t.alpha).from(t)));
 		using TT = decltype(any(select(t.beta).from(t)));
 		using TF = decltype(any(select(f.omega).from(t)));
+		static_assert(not sqlpp::is_named_expression_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_nameless_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TI>::value, "type requirement");
-		static_assert(sqlpp::is_numeric_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_nameless_expression_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_numeric_t<TF>::value, "tFpe requirement");
 		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_nameless_expression_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_integral_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_floating_point_t<TT>::value, "type requirement");
@@ -118,13 +171,19 @@ int main()
 		using TI = decltype(some(select(t.alpha).from(t)));
 		using TT = decltype(some(select(t.beta).from(t)));
 		using TF = decltype(some(select(f.omega).from(t)));
+		static_assert(not sqlpp::is_named_expression_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_nameless_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_nameless_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_text_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_nameless_expression_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_integral_t<TT>::value, "type requirement");
 		static_assert(not sqlpp::is_floating_point_t<TT>::value, "type requirement");
 		static_assert(sqlpp::is_text_t<TT>::value, "type requirement");
@@ -137,9 +196,11 @@ int main()
 	{
 		using TI = decltype(avg(t.alpha));
 		using TF = decltype(avg(f.omega));
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_integral_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_floating_point_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_integral_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
@@ -150,52 +211,120 @@ int main()
 		using TI = decltype(count(t.alpha));
 		using TT = decltype(count(t.beta));
 		using TF = decltype(count(f.omega));
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_floating_point_t<TI>::value, "type requirement");
-		static_assert(sqlpp::is_numeric_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
-		static_assert(sqlpp::is_integral_t<TT>::value, "type requirement");
-		static_assert(not sqlpp::is_floating_point_t<TT>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_integral_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_floating_point_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_numeric_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_integral_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_floating_point_t<TT>::value, "type requirement");
 	}
 
 	// Test max
 	{
 		using TI = decltype(max(t.alpha));
 		using TF = decltype(max(f.omega));
+		using TT = decltype(max(t.beta));
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_floating_point_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_integral_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_text_t<TT>::value, "type requirement");
 	}
 
 	// Test min
 	{
 		using TI = decltype(min(t.alpha));
 		using TF = decltype(min(f.omega));
+		using TT = decltype(min(t.beta));
+		static_assert(sqlpp::is_named_expression_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_floating_point_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_integral_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(not sqlpp::is_numeric_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_text_t<TT>::value, "type requirement");
 	}
 
 	// Test sum
 	{
 		using TI = decltype(sum(t.alpha));
 		using TF = decltype(sum(f.omega));
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TI>::value, "type requirement");
 		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
 		static_assert(not sqlpp::is_floating_point_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_named_expression_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_numeric_t<TF>::value, "type requirement");
 		static_assert(not sqlpp::is_integral_t<TF>::value, "type requirement");
 		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
 	}
 
+	// MISC FUNCTIONS
+  // --------------
+
+	// test value
+	{
+		using TB = decltype(sqlpp::value(true));
+		using TI = decltype(sqlpp::value(7));
+		using TF = decltype(sqlpp::value(1.5));
+		using TT = decltype(sqlpp::value("cheesecake"));
+		static_assert(not sqlpp::is_named_expression_t<TB>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TB>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TB>::value, "type requirement");
+		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_text_t<TT>::value, "type requirement");
+	}
+
+	// test flatten
+	{
+		using TB = decltype(flatten(t.gamma, db));
+		using TI = decltype(flatten(t.alpha, db));
+		using TF = decltype(flatten(f.omega, db));
+		using TT = decltype(flatten(t.beta, db));
+		static_assert(not sqlpp::is_named_expression_t<TB>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TB>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TB>::value, "type requirement");
+		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_text_t<TT>::value, "type requirement");
+	}
+
+	// test verbatim
+	{
+		using TB = decltype(sqlpp::verbatim<sqlpp::boolean>("1"));
+		using TI = decltype(sqlpp::verbatim<sqlpp::bigint>("42"));
+		using TF = decltype(sqlpp::verbatim<sqlpp::floating_point>("1.5"));
+		using TT = decltype(sqlpp::verbatim<sqlpp::text>("cheesecake"));
+		static_assert(not sqlpp::is_named_expression_t<TB>::value, "type requirement");
+		static_assert(sqlpp::is_boolean_t<TB>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TB>::value, "type requirement");
+		static_assert(sqlpp::is_integral_t<TI>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TI>::value, "type requirement");
+		static_assert(sqlpp::is_floating_point_t<TF>::value, "type requirement");
+		static_assert(not sqlpp::is_named_expression_t<TT>::value, "type requirement");
+		static_assert(sqlpp::is_text_t<TT>::value, "type requirement");
+	}
+
 	return 0;
 }