From 3e008a2b04078490e9a09fabc2b8eed758507c49 Mon Sep 17 00:00:00 2001
From: rbock <rbock@eudoxos.de>
Date: Wed, 6 Apr 2016 10:16:35 +0200
Subject: [PATCH] Intermediate state

---
 include/sqlpp11/basic_expression_operators.h  | 51 +++++-----
 .../data_types/floating_point/result_field.h  |  1 -
 test_serializer/In.cpp                        |  7 +-
 test_static_asserts/CMakeLists.txt            |  2 +
 test_static_asserts/date.cpp                  | 21 +++--
 test_static_asserts/date_time.cpp             | 21 +++--
 test_static_asserts/no_self_compare.cpp       | 74 +++++++++++++++
 test_static_asserts/text.cpp                  | 93 +++++++++++++++++++
 tests/SelectType.cpp                          |  3 +-
 tests/Update.cpp                              |  2 +-
 10 files changed, 222 insertions(+), 53 deletions(-)
 create mode 100644 test_static_asserts/no_self_compare.cpp
 create mode 100644 test_static_asserts/text.cpp

diff --git a/include/sqlpp11/basic_expression_operators.h b/include/sqlpp11/basic_expression_operators.h
index 23dd5b6c..665de9fb 100644
--- a/include/sqlpp11/basic_expression_operators.h
+++ b/include/sqlpp11/basic_expression_operators.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -41,10 +41,11 @@
 
 namespace sqlpp
 {
-  SQLPP_PORTABLE_STATIC_ASSERT(assert_valid_rhs_comparison_operand_t, "invalid rhs operand in comparison");
+  SQLPP_PORTABLE_STATIC_ASSERT(assert_comparison_valid_rhs_operand_t, "invalid rhs operand in comparison");
+  SQLPP_PORTABLE_STATIC_ASSERT(assert_comparison_lhs_rhs_differ_t, "identical lhs and rhs operand types in comparison");
 
-  template <typename LhsValueType, typename RhsType>
-  using check_rhs_comparison_operand_t =
+  template <typename LhsType, typename LhsValueType, typename RhsType>
+  using check_rhs_comparison_operand_t = static_combined_check_t<
       static_check_t<(is_expression_t<sqlpp::wrap_operand_t<RhsType>>::value  // expressions are OK
                       or
                       is_multi_expression_t<sqlpp::wrap_operand_t<RhsType>>::value)  // multi-expressions like ANY are
@@ -52,14 +53,12 @@ namespace sqlpp
                          and
                          LhsValueType::template _is_valid_operand<
                              sqlpp::wrap_operand_t<RhsType>>::value,  // the correct value type is required, of course
-                     assert_valid_rhs_comparison_operand_t>;
+                     assert_comparison_valid_rhs_operand_t>,
+      static_check_t<not std::is_same<LhsType, RhsType>::value, assert_comparison_lhs_rhs_differ_t>>;
 
-  SQLPP_PORTABLE_STATIC_ASSERT(assert_valid_in_arguments_t, "at least one operand of in() is not valid");
-
-  template <typename LhsValueType, typename... InTypes>
+  template <typename LhsType, typename LhsValueType, typename... InTypes>
   using check_rhs_in_arguments_t =
-      static_check_t<logic::all_t<check_rhs_comparison_operand_t<LhsValueType, InTypes>::value...>::value,
-                     assert_valid_in_arguments_t>;
+      static_combined_check_t<check_rhs_comparison_operand_t<LhsType, LhsValueType, InTypes>...>;
 
   namespace detail
   {
@@ -118,7 +117,7 @@ namespace sqlpp
   {
     template <template <typename Lhs, typename Rhs> class NewExpr, typename T>
     using _new_binary_expression_t =
-        new_binary_expression_t<check_rhs_comparison_operand_t<ValueType, wrap_operand_t<T>>,
+        new_binary_expression_t<check_rhs_comparison_operand_t<Expr, ValueType, wrap_operand_t<T>>,
                                 NewExpr,
                                 Expr,
                                 wrap_operand_t<T>>;
@@ -134,18 +133,18 @@ namespace sqlpp
     template <template <typename Lhs, typename... Rhs> class NewExpr, typename... T>
     struct _new_nary_expression
     {
-      using type =
-          new_nary_expression_t<logic::all_t<check_rhs_comparison_operand_t<ValueType, wrap_operand_t<T>>::value...>,
-                                NewExpr,
-                                Expr,
-                                wrap_operand_t<T>...>;
+      using type = new_nary_expression_t<
+          logic::all_t<check_rhs_comparison_operand_t<Expr, ValueType, wrap_operand_t<T>>::value...>,
+          NewExpr,
+          Expr,
+          wrap_operand_t<T>...>;
     };
 
     template <typename T>
     _new_binary_expression_t<equal_to_t, T> operator==(T t) const
     {
       using rhs = wrap_operand_t<T>;
-      check_rhs_comparison_operand_t<ValueType, rhs>::_();
+      check_rhs_comparison_operand_t<Expr, ValueType, rhs>::_();
 
       return {*static_cast<const Expr*>(this), {rhs{t}}};
     }
@@ -154,7 +153,7 @@ namespace sqlpp
     _new_binary_expression_t<not_equal_to_t, T> operator!=(T t) const
     {
       using rhs = wrap_operand_t<T>;
-      check_rhs_comparison_operand_t<ValueType, rhs>::_();
+      check_rhs_comparison_operand_t<Expr, ValueType, rhs>::_();
 
       return {*static_cast<const Expr*>(this), {rhs{t}}};
     }
@@ -163,7 +162,7 @@ namespace sqlpp
     _new_binary_expression_t<less_than_t, T> operator<(T t) const
     {
       using rhs = wrap_operand_t<T>;
-      check_rhs_comparison_operand_t<ValueType, rhs>::_();
+      check_rhs_comparison_operand_t<Expr, ValueType, rhs>::_();
 
       return {*static_cast<const Expr*>(this), rhs{t}};
     }
@@ -172,7 +171,7 @@ namespace sqlpp
     _new_binary_expression_t<less_equal_t, T> operator<=(T t) const
     {
       using rhs = wrap_operand_t<T>;
-      check_rhs_comparison_operand_t<ValueType, rhs>::_();
+      check_rhs_comparison_operand_t<Expr, ValueType, rhs>::_();
 
       return {*static_cast<const Expr*>(this), rhs{t}};
     }
@@ -181,7 +180,7 @@ namespace sqlpp
     _new_binary_expression_t<greater_than_t, T> operator>(T t) const
     {
       using rhs = wrap_operand_t<T>;
-      check_rhs_comparison_operand_t<ValueType, rhs>::_();
+      check_rhs_comparison_operand_t<Expr, ValueType, rhs>::_();
 
       return {*static_cast<const Expr*>(this), rhs{t}};
     }
@@ -190,7 +189,7 @@ namespace sqlpp
     _new_binary_expression_t<greater_equal_t, T> operator>=(T t) const
     {
       using rhs = wrap_operand_t<T>;
-      check_rhs_comparison_operand_t<ValueType, rhs>::_();
+      check_rhs_comparison_operand_t<Expr, ValueType, rhs>::_();
 
       return {*static_cast<const Expr*>(this), rhs{t}};
     }
@@ -220,13 +219,13 @@ namespace sqlpp
     //	template <typename... T>
     //	_new_nary_expression_t<in_t, T...> in(T... t) const
     //	{
-    //		check_rhs_in_arguments_t<ValueType, wrap_operand_t<T>...>::_();
+    //		check_rhs_in_arguments_t<Expr, ValueType, wrap_operand_t<T>...>::_();
     //		return {*static_cast<const Expr*>(this), wrap_operand_t<T>{t}...};
     //	}
     template <typename... T>
     typename _new_nary_expression<in_t, T...>::type in(T... t) const
     {
-      check_rhs_in_arguments_t<ValueType, wrap_operand_t<T>...>::_();
+      check_rhs_in_arguments_t<Expr, ValueType, wrap_operand_t<T>...>::_();
       return {*static_cast<const Expr*>(this), typename wrap_operand<T>::type{t}...};
     }
 
@@ -234,13 +233,13 @@ namespace sqlpp
     //	template <typename... T>
     //	_new_nary_expression_t<not_in_t, T...> not_in(T... t) const
     //	{
-    //		check_rhs_in_arguments_t<ValueType, wrap_operand_t<T>...>::_();
+    //		check_rhs_in_arguments_t<Expr, ValueType, wrap_operand_t<T>...>::_();
     //		return {*static_cast<const Expr*>(this), wrap_operand_t<T>{t}...};
     //	}
     template <typename... T>
     typename _new_nary_expression<not_in_t, T...>::type not_in(T... t) const
     {
-      check_rhs_in_arguments_t<ValueType, wrap_operand_t<T>...>::_();
+      check_rhs_in_arguments_t<Expr, ValueType, wrap_operand_t<T>...>::_();
       return {*static_cast<const Expr*>(this), typename wrap_operand<T>::type{t}...};
     }
 
diff --git a/include/sqlpp11/data_types/floating_point/result_field.h b/include/sqlpp11/data_types/floating_point/result_field.h
index f03d30b6..a644b80b 100644
--- a/include/sqlpp11/data_types/floating_point/result_field.h
+++ b/include/sqlpp11/data_types/floating_point/result_field.h
@@ -27,7 +27,6 @@
 #ifndef SQLPP_FLOATING_POINT_RESULT_FIELD_H
 #define SQLPP_FLOATING_POINT_RESULT_FIELD_H
 
-#include <sqlpp11/basic_expression_operators.h>
 #include <sqlpp11/exception.h>
 #include <sqlpp11/result_field.h>
 #include <sqlpp11/result_field_base.h>
diff --git a/test_serializer/In.cpp b/test_serializer/In.cpp
index 989a0805..89fc09c7 100644
--- a/test_serializer/In.cpp
+++ b/test_serializer/In.cpp
@@ -44,10 +44,9 @@ int In(int, char* [])
   const auto bar = test::TabBar{};
 
   // Individual values
-  compare(__LINE__, foo.omega.in(foo.omega), "tab_foo.omega IN(tab_foo.omega)");
-  compare(__LINE__, foo.omega.in(foo.omega, bar.alpha), "tab_foo.omega IN(tab_foo.omega,tab_bar.alpha)");
-  compare(__LINE__, foo.omega.in(foo.omega, bar.alpha, sqlpp::value(17)),
-          "tab_foo.omega IN(tab_foo.omega,tab_bar.alpha,17)");
+  compare(__LINE__, foo.omega.in(17), "tab_foo.omega IN(17)");
+  compare(__LINE__, foo.omega.in(17, bar.alpha), "tab_foo.omega IN(17,tab_bar.alpha)");
+  compare(__LINE__, foo.omega.in(17, bar.alpha, sqlpp::value(19)), "tab_foo.omega IN(17,tab_bar.alpha,19)");
 
   // Lists
   compare(__LINE__, foo.omega.in(sqlpp::value_list(std::vector<float>{1.7f, 2.5f, 17.f, 0.f})),
diff --git a/test_static_asserts/CMakeLists.txt b/test_static_asserts/CMakeLists.txt
index 0416116a..338f3cd9 100644
--- a/test_static_asserts/CMakeLists.txt
+++ b/test_static_asserts/CMakeLists.txt
@@ -36,5 +36,7 @@ test_compile(where)
 test_compile(insert)
 test_compile(date)
 test_compile(date_time)
+test_compile(text)
+test_compile(no_self_compare)
 test_compile(unwrapped_bool)
 
diff --git a/test_static_asserts/date.cpp b/test_static_asserts/date.cpp
index 66d9cb6f..c2495840 100644
--- a/test_static_asserts/date.cpp
+++ b/test_static_asserts/date.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2015, Roland Bock
+ * Copyright (c) 2015-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -66,20 +66,21 @@ namespace
   void allowed_comparands()
   {
     static_check_comparison<sqlpp::consistent_t>(std::chrono::system_clock::now());
-    static_check_comparison<sqlpp::consistent_t>(t.someDayPoint);
+    static_check_comparison<sqlpp::consistent_t>(t.otherDayPoint);
     static_check_comparison<sqlpp::consistent_t>(t.someTimePoint);
+    static_check_comparison<sqlpp::consistent_t>(t.otherTimePoint);
   }
 
   void disallowed_comparands()
   {
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(17);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>('a');
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(std::string("a"));
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someBool);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someFloat);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someInt);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someString);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(17);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>('a');
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(std::string("a"));
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someBool);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someFloat);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someInt);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someString);
   }
 }
 
diff --git a/test_static_asserts/date_time.cpp b/test_static_asserts/date_time.cpp
index 2c16e2e3..bd1c533b 100644
--- a/test_static_asserts/date_time.cpp
+++ b/test_static_asserts/date_time.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2015, Roland Bock
+ * Copyright (c) 2015-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -67,19 +67,20 @@ namespace
   {
     static_check_comparison<sqlpp::consistent_t>(std::chrono::system_clock::now());
     static_check_comparison<sqlpp::consistent_t>(t.someDayPoint);
-    static_check_comparison<sqlpp::consistent_t>(t.someTimePoint);
+    static_check_comparison<sqlpp::consistent_t>(t.otherDayPoint);
+    static_check_comparison<sqlpp::consistent_t>(t.otherTimePoint);
   }
 
   void disallowed_comparands()
   {
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(17);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>('a');
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(std::string("a"));
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someBool);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someFloat);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someInt);
-    static_check_comparison<sqlpp::assert_valid_rhs_comparison_operand_t>(t.someString);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(17);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>('a');
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(std::string("a"));
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someBool);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someFloat);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someInt);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someString);
   }
 }
 
diff --git a/test_static_asserts/no_self_compare.cpp b/test_static_asserts/no_self_compare.cpp
new file mode 100644
index 00000000..0621897b
--- /dev/null
+++ b/test_static_asserts/no_self_compare.cpp
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2015-2016, 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.
+ */
+
+#include <iostream>
+#include <MockDb.h>
+#include "AssertTables.h"
+#include <sqlpp11/sqlpp11.h>
+
+namespace
+{
+  constexpr auto t = test::TabAllTypes{};
+
+  template <typename T>
+  void print_type_on_error(std::true_type)
+  {
+  }
+
+  template <typename T>
+  void print_type_on_error(std::false_type)
+  {
+    T::_print_me_;
+  }
+
+  template <typename Assert, typename Operand>
+  void static_check_comparison(const Operand& operand)
+  {
+    using CheckResult = sqlpp::check_rhs_comparison_operand_t<Operand, Operand>;
+    using ExpectedCheckResult = std::is_same<CheckResult, Assert>;
+    static_assert(ExpectedCheckResult::value, "Unexpected check result");
+    print_type_on_error<CheckResult>(ExpectedCheckResult{});
+
+    using ReturnType = sqlpp::detail::make_type_set_t<decltype(operand < operand), decltype(operand <= operand),
+                                                      decltype(operand == operand), decltype(operand != operand),
+                                                      decltype(operand >= operand), decltype(operand > operand)>;
+    using ExpectedReturnType =
+        sqlpp::logic::all_t<Assert::value xor
+                            std::is_same<ReturnType, sqlpp::detail::type_set<sqlpp::bad_statement>>::value>;
+    static_assert(ExpectedReturnType::value, "Unexpected return type");
+    print_type_on_error<ReturnType>(ExpectedReturnType{});
+  }
+
+  void disallowed_self_comparison()
+  {
+    // static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someString);
+  }
+}
+
+int main(int, char* [])
+{
+  t.someString == t.someString;
+  // disallowed_self_comparison();
+}
diff --git a/test_static_asserts/text.cpp b/test_static_asserts/text.cpp
new file mode 100644
index 00000000..0cdb350a
--- /dev/null
+++ b/test_static_asserts/text.cpp
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2015-2016, 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.
+ */
+
+#include <iostream>
+#include <MockDb.h>
+#include "AssertTables.h"
+#include <sqlpp11/sqlpp11.h>
+
+namespace
+{
+  constexpr auto t = test::TabAllTypes{};
+
+  template <typename T>
+  void print_type_on_error(std::true_type)
+  {
+  }
+
+  template <typename T>
+  void print_type_on_error(std::false_type)
+  {
+    T::_print_me_;
+  }
+
+  template <typename Assert, typename Operand>
+  void static_check_comparison(const Operand& operand)
+  {
+    using CheckResult = sqlpp::check_rhs_comparison_operand_t<decltype(t.someString), Operand>;
+    using ExpectedCheckResult = std::is_same<CheckResult, Assert>;
+    static_assert(ExpectedCheckResult::value, "Unexpected check result");
+    print_type_on_error<CheckResult>(ExpectedCheckResult{});
+
+    using ReturnType = sqlpp::detail::make_type_set_t<
+        decltype(t.someString < operand), decltype(t.someString <= operand), decltype(t.someString == operand),
+        decltype(t.someString != operand), decltype(t.someString >= operand), decltype(t.someString > operand),
+        decltype(t.someString.in(operand)), decltype(t.someString.in(operand, operand)),
+        decltype(t.someString.not_in(operand)), decltype(t.someString.not_in(operand, operand))>;
+    using ExpectedReturnType =
+        sqlpp::logic::all_t<Assert::value xor
+                            std::is_same<ReturnType, sqlpp::detail::type_set<sqlpp::bad_statement>>::value>;
+    static_assert(ExpectedReturnType::value, "Unexpected return type");
+    print_type_on_error<ReturnType>(ExpectedReturnType{});
+  }
+
+  void allowed_comparands()
+  {
+    static_check_comparison<sqlpp::consistent_t>("");
+    static_check_comparison<sqlpp::consistent_t>('d');
+    static_check_comparison<sqlpp::consistent_t>(std::string(""));
+    static_check_comparison<sqlpp::consistent_t>(t.otherText);
+  }
+
+  void disallowed_comparands()
+  {
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(17);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(17.4);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someBool);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someFloat);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someInt);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someDayPoint);
+    static_check_comparison<sqlpp::assert_comparison_valid_rhs_operand_t>(t.someTimePoint);
+  }
+}
+
+int main(int, char* [])
+{
+#error : This must fail:
+  t.someString + 1;
+  allowed_comparands();
+  disallowed_comparands();
+}
diff --git a/tests/SelectType.cpp b/tests/SelectType.cpp
index c1ecb262..712491e0 100644
--- a/tests/SelectType.cpp
+++ b/tests/SelectType.cpp
@@ -358,7 +358,8 @@ int SelectType(int, char* [])
   static_assert(sqlpp::is_numeric_t<T>::value, "T has to be numeric");
   static_assert(sqlpp::is_numeric_t<decltype(t.alpha)>::value, "TabBar.alpha has to be a numeric");
   ((t.alpha + 7) + 4).asc();
-  static_assert(sqlpp::is_boolean_t<decltype(t.gamma == t.gamma)>::value, "Comparison expression have to be boolean");
+  static_assert(sqlpp::is_boolean_t<decltype(t.gamma != not(t.gamma))>::value,
+                "Comparison expression have to be boolean");
   !t.gamma;
   serialize(t.beta < "kaesekuchen", printer).str();
   serialize(t.beta + "hallenhalma", printer).str();
diff --git a/tests/Update.cpp b/tests/Update.cpp
index 16a06cb4..f02e2ae0 100644
--- a/tests/Update.cpp
+++ b/tests/Update.cpp
@@ -54,7 +54,7 @@ int Update(int, char* [])
   serialize(update(t), printer).str();
   serialize(update(t).set(t.gamma = false), printer).str();
   serialize(update(t).set(t.gamma = false).where(t.beta != "transparent"), printer).str();
-  serialize(update(t).set(t.beta = "opaque").where(t.beta != t.beta), printer).str();
+  serialize(update(t).set(t.beta = "opaque").where(t.beta != t.beta + "this is nonsense"), printer).str();
   auto u = dynamic_update(db, t).dynamic_set(t.gamma = false).dynamic_where();
   u.assignments.add(t.beta = "cannot update gamma a second time");
   u.where.add(t.gamma != false);