#471 serializers: ensure float precision (#472)

* value: add missing includes
* mysql, sqlite3: use explicitly *out* stringstreams for serialization
* postgresql: fix: use max_digits10 instead of digits10
* detail: add float_safe_ostringstream, ensuring floats are serialized with enough precision
* mysql, postgresql, sqlite3, tests: fix: set float-precision for all streams
* run clang-format on changed files
* inline remove_cvref.h
* replace unspecific "wrapper" with concrete type name
* tests: split connector specific tests out of serialize/Float

include/sqlpp11/detail/float_safe_ostringstream.h

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2023, 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 SQLPP11_COLUMN_TUPLE_FLOAT_SAFE_OSTRINGSTREAM_H
+#define SQLPP11_COLUMN_TUPLE_FLOAT_SAFE_OSTRINGSTREAM_H
+
+#include <limits>
+#include <sstream>
+#include <type_traits>
+#include <utility>
+
+#include <sqlpp11/detail/enable_if.h>
+
+namespace sqlpp
+{
+  namespace detail
+  {
+    template <typename T, typename = void>
+    struct float_safe_ostringstream_implementation
+    {
+      template <typename U>
+      void operator()(std::ostringstream& os, U&& x) const
+      {
+        os << std::forward<U>(x);
+      }
+    };
+
+    template <typename T>
+    struct float_safe_ostringstream_implementation<T, enable_if_t<std::is_floating_point<T>::value>>
+    {
+      template <typename U>
+      void operator()(std::ostringstream& os, U&& x) const
+      {
+        auto const old_precision{os.precision(std::numeric_limits<T>::max_digits10)};
+        os << std::forward<U>(x);
+        os.precision(old_precision);
+      }
+    };
+
+    struct float_safe_ostringstream : std::ostringstream
+    {
+      template <typename T>
+      friend float_safe_ostringstream& operator<<(float_safe_ostringstream& os, T&& x)
+      {
+        float_safe_ostringstream_implementation<typename std::decay<T>::type>{}(os, x);
+        return os;
+      }
+    };
+  }  // namespace detail
+}  // namespace sqlpp
+
+#endif

include/sqlpp11/mysql/connection.h

@@ -28,6 +28,7 @@
 #define SQLPP_MYSQL_CONNECTION_H
 
 #include <sqlpp11/connection.h>
+#include <sqlpp11/detail/float_safe_ostringstream.h>
 #include <sqlpp11/exception.h>
 #include <sqlpp11/mysql/bind_result.h>
 #include <sqlpp11/mysql/char_result.h>
@@ -247,7 +248,7 @@ namespace sqlpp
       }
 
       const connection& _db;
-      std::stringstream _os;
+      sqlpp::detail::float_safe_ostringstream _os;
     };
 
     std::integral_constant<char, '`'> get_quote_left(const serializer_t&);

include/sqlpp11/postgresql/connection.h

@@ -33,6 +33,7 @@
 #include <sstream>
 
 #include <sqlpp11/connection.h>
+#include <sqlpp11/detail/float_safe_ostringstream.h>
 #include <sqlpp11/postgresql/bind_result.h>
 #include <sqlpp11/postgresql/result_field.h>
 #include <sqlpp11/postgresql/connection_config.h>
@@ -125,7 +126,7 @@ namespace sqlpp
       }
 
       const connection& _db;
-      std::ostringstream _os;
+      sqlpp::detail::float_safe_ostringstream _os;
       size_t _count{1};
     };
 

include/sqlpp11/postgresql/prepared_statement.h

@@ -32,7 +32,7 @@
 #include <memory>
 #include <string>
 #include <sqlpp11/chrono.h>
-
+#include <sqlpp11/detail/float_safe_ostringstream.h>
 #include <sqlpp11/postgresql/exception.h>
 
 namespace sqlpp
@@ -127,9 +127,8 @@ namespace sqlpp
       _handle->nullValues[index] = is_null;
       if (!is_null)
       {
-        std::ostringstream out;
-        out.precision(std::numeric_limits<double>::digits10);
-        out << std::fixed << *value;
+        sqlpp::detail::float_safe_ostringstream out;
+        out << *value;
         _handle->paramValues[index] = out.str();
       }
     }

include/sqlpp11/sqlite3/connection.h

@@ -33,6 +33,7 @@
 #include <sqlite3.h>
 #endif
 #include <sqlpp11/connection.h>
+#include <sqlpp11/detail/float_safe_ostringstream.h>
 #include <sqlpp11/exception.h>
 #include <sqlpp11/schema.h>
 #include <sqlpp11/serialize.h>
@@ -184,7 +185,7 @@ namespace sqlpp
       }
 
       const connection& _db;
-      std::stringstream _os;
+      sqlpp::detail::float_safe_ostringstream _os;
       size_t _count;
     };
 

include/sqlpp11/value.h

@@ -27,7 +27,9 @@
 #ifndef SQLPP11_VALUE_H
 #define SQLPP11_VALUE_H
 
+#include <sqlpp11/expression_operators.h>
 #include <sqlpp11/type_traits.h>
+#include <sqlpp11/wrap_operand.h>
 
 namespace sqlpp
 {

tests/core/serialize/CMakeLists.txt

@@ -31,6 +31,7 @@ set(test_files
     CustomQuery.cpp
     DynamicWhere.cpp
     Exists.cpp
+    Float.cpp
     ForUpdate.cpp
     From.cpp
     In.cpp

tests/core/serialize/Float.cpp

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2023, 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 <sqlpp11/data_types/floating_point.h>
+#include <sqlpp11/detail/float_safe_ostringstream.h>
+#include <sqlpp11/value.h>
+
+#include "compare.h"
+
+namespace
+{
+  template <typename T>
+  void float_safe_ostringstream_serializes_value_as(int line, T value, std::string expected)
+  {
+    sqlpp::detail::float_safe_ostringstream os;
+    os << value;
+    assert_equal(line, os.str(), expected);
+  }
+
+  template <typename T>
+  void float_safe_ostringstream_serializes_in_deserializable_format(int line, T value)
+  {
+    sqlpp::detail::float_safe_ostringstream os;
+    os << value;
+    std::istringstream is{os.str()};
+    T deserialized;
+    is >> deserialized;
+    assert_equal(line, deserialized, value);
+  }
+
+  template <typename T>
+  std::string string_for_10_0000086()
+  {
+    switch (std::numeric_limits<T>::max_digits10)
+    {
+      case 9:
+        return "10.0000086";
+      case 17:
+        return "10.000008599999999";
+      case 21:
+        return "10.0000086000000000001";
+      default:
+        throw std::logic_error("Unknown floating point digit count");
+    }
+  }
+}  // namespace
+
+int Float(int, char*[])
+{
+  float_safe_ostringstream_serializes_value_as(__LINE__, 10.0000086f, string_for_10_0000086<float>());
+  float_safe_ostringstream_serializes_value_as(__LINE__, 10.0000086, string_for_10_0000086<double>());
+  float_safe_ostringstream_serializes_value_as(__LINE__, 10.0000086l, string_for_10_0000086<long double>());
+
+  float_safe_ostringstream_serializes_in_deserializable_format(__LINE__, 10.0000086f);
+  float_safe_ostringstream_serializes_in_deserializable_format(__LINE__, 10.0000086);
+  float_safe_ostringstream_serializes_in_deserializable_format(__LINE__, 10.0000086l);
+
+  compare(__LINE__, sqlpp::value(10.0000114), "10.0000114");
+
+  return 0;
+}

tests/core/serialize/In.cpp

@@ -49,8 +49,8 @@ int In(int, char* [])
   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})),
-          "tab_foo.omega IN(1.7,2.5,17,0)");
+  compare(__LINE__, foo.omega.in(sqlpp::value_list(std::vector<float>{1.75f, 2.5f, 17.f, 0.f})),
+          "tab_foo.omega IN(1.75,2.5,17,0)");
 
   // Sub select
   compare(__LINE__, foo.omega.in(select(bar.alpha).from(bar).unconditionally()),

tests/core/serialize/compare.h

@@ -31,6 +31,17 @@
 
 namespace
 {
+  template <typename Result, typename Expected>
+  void assert_equal(int lineNo, const Result& result, const Expected& expected)
+  {
+    if (result != expected)
+    {
+      std::cerr << __FILE__ << " " << lineNo << '\n' << "Expected: -->|" << expected << "|<--\n"
+                << "Received: -->|" << result << "|<--\n";
+      throw std::runtime_error("unexpected result");
+    }
+  }
+
   template <typename Expression>
   void compare(int lineNo, const Expression& expr, const std::string& expected)
   {
@@ -38,12 +49,7 @@ namespace
 
     const auto result = serialize(expr, printer).str();
 
-    if (result != expected)
-    {
-      std::cerr << __FILE__ << " " << lineNo << '\n' << "Expected: -->|" << expected << "|<--\n"
-                << "Received: -->|" << result << "|<--\n";
-      throw std::runtime_error("unexpected serialization result");
-    }
+    assert_equal(lineNo, result, expected);
   }
 }
 

tests/core/usage/MockDb.h

@@ -28,6 +28,7 @@
 
 #include <iostream>
 #include <sqlpp11/connection.h>
+#include <sqlpp11/detail/float_safe_ostringstream.h>
 #include <sqlpp11/transaction.h>
 #include <sqlpp11/data_types/no_value.h>
 #include <sqlpp11/schema.h>
@@ -49,7 +50,7 @@ struct MockDb : public sqlpp::connection
 
   struct _serializer_context_t
   {
-    std::ostringstream _os;
+    ::sqlpp::detail::float_safe_ostringstream _os;
 
     _serializer_context_t() = default;
     _serializer_context_t(const _serializer_context_t& rhs)
@@ -68,7 +69,7 @@ struct MockDb : public sqlpp::connection
     }
 
     template <typename T>
-    std::ostream& operator<<(T t)
+    ::sqlpp::detail::float_safe_ostringstream& operator<<(T t)
     {
       return _os << t;
     }

tests/mysql/CMakeLists.txt

@@ -22,4 +22,5 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+add_subdirectory(serialize)
 add_subdirectory(usage)

tests/mysql/serialize/CMakeLists.txt

@@ -0,0 +1,51 @@
+# Copyright (c) 2023, 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.
+
+find_package(Threads REQUIRED)
+
+set(test_files
+    Float.cpp
+)
+
+create_test_sourcelist(test_sources test_main.cpp ${test_files})
+add_executable(sqlpp11_mysql_serialize_tests ${test_sources})
+target_link_libraries(sqlpp11_mysql_serialize_tests PRIVATE sqlpp11::mysql sqlpp11_testing sqlpp11_mysql_testing)
+target_link_libraries(sqlpp11_mysql_serialize_tests PRIVATE Threads::Threads)
+if(NOT MSVC)
+    target_compile_options(sqlpp11_mysql_serialize_tests PRIVATE -Wall -Wextra -pedantic)
+endif()
+
+# conditionally bump to a higher C++ standard to test compatibility
+if (SQLPP11_TESTS_CXX_STD)
+    set_property(TARGET sqlpp11_mysql_serialize_tests PROPERTY CXX_STANDARD ${SQLPP11_TESTS_CXX_STD})
+    set_property(TARGET sqlpp11_mysql_serialize_tests PROPERTY CXX_STANDARD_REQUIRED yes)
+    set_property(TARGET sqlpp11_mysql_serialize_tests PROPERTY CXX_EXTENSIONS no)
+endif()
+
+foreach(test_file IN LISTS test_files)
+    get_filename_component(test ${test_file} NAME_WLE)
+    add_test(NAME sqlpp11.mysql.serialize.${test}
+        COMMAND sqlpp11_mysql_serialize_tests ${test}
+    )
+endforeach()

tests/mysql/serialize/Float.cpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2023, 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 <sqlpp11/data_types/floating_point.h>
+#include <sqlpp11/value.h>
+
+#include "compare.h"
+
+int Float(int, char*[])
+{
+  compare(__LINE__, sqlpp::value(10.0000114), "10.0000114");
+
+  return 0;
+}

tests/mysql/serialize/compare.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2013-2015, 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_TESTS_MYSQL_COMPARE_H
+#define SQLPP_TESTS_MYSQL_COMPARE_H
+
+#include <sqlpp11/mysql/connection.h>
+#include <iostream>
+
+namespace
+{
+  template <typename Result, typename Expected>
+  void assert_equal(int lineNo, const Result& result, const Expected& expected)
+  {
+    if (result != expected)
+    {
+      std::cerr << __FILE__ << " " << lineNo << '\n'
+                << "Expected: -->|" << expected << "|<--\n"
+                << "Received: -->|" << result << "|<--\n";
+      throw std::runtime_error("unexpected result");
+    }
+  }
+
+  template <typename Expression>
+  void compare(int lineNo, const Expression& expr, const std::string& expected)
+  {
+    auto config{std::make_shared<sqlpp::mysql::connection_config>()};
+    config->user = "root";
+    config->database = "sqlpp_mysql";
+    config->debug = true;
+    try
+    {
+      sqlpp::mysql::connection db(config);
+    }
+    catch (const sqlpp::exception& e)
+    {
+      std::cerr << e.what() << std::endl;
+      throw std::logic_error("For testing, you'll need to create a database sqlpp_mysql for user root (no password)");
+    }
+
+    sqlpp::mysql::connection connection{config};
+    sqlpp::mysql::serializer_t printer{connection};
+
+    const auto result = serialize(expr, printer).str();
+
+    assert_equal(lineNo, result, expected);
+  }
+}  // namespace
+
+#endif

tests/postgresql/CMakeLists.txt

@@ -23,4 +23,5 @@
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 add_subdirectory(constraints)
+add_subdirectory(serialize)
 add_subdirectory(usage)

tests/postgresql/serialize/CMakeLists.txt

@@ -0,0 +1,48 @@
+# Copyright (c) 2023, 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.
+
+set(test_files
+    Float.cpp
+)
+
+create_test_sourcelist(test_sources test_main.cpp ${test_files})
+add_executable(sqlpp11_postgresql_serialize_tests ${test_sources})
+target_link_libraries(sqlpp11_postgresql_serialize_tests PRIVATE sqlpp11::postgresql sqlpp11_testing sqlpp11_postgresql_testing)
+if(NOT MSVC)
+    target_compile_options(sqlpp11_postgresql_serialize_tests PRIVATE -Wall -Wextra -pedantic)
+endif()
+
+# conditionally bump to a higher C++ standard to test compatibility
+if (SQLPP11_TESTS_CXX_STD)
+    set_property(TARGET sqlpp11_postgresql_serialize_tests PROPERTY CXX_STANDARD ${SQLPP11_TESTS_CXX_STD})
+    set_property(TARGET sqlpp11_postgresql_serialize_tests PROPERTY CXX_STANDARD_REQUIRED yes)
+    set_property(TARGET sqlpp11_postgresql_serialize_tests PROPERTY CXX_EXTENSIONS no)
+endif()
+
+foreach(test_file IN LISTS test_files)
+    get_filename_component(test ${test_file} NAME_WLE)
+    add_test(NAME sqlpp11.postgresql.serialize.${test}
+        COMMAND sqlpp11_postgresql_serialize_tests ${test}
+    )
+endforeach()

tests/postgresql/serialize/Float.cpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2023, 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 <sqlpp11/data_types/floating_point.h>
+#include <sqlpp11/value.h>
+
+#include "compare.h"
+
+int Float(int, char*[])
+{
+  compare(__LINE__, sqlpp::value(10.0000114), "10.0000114");
+
+  return 0;
+}

tests/postgresql/serialize/compare.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2013-2015, 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_TESTS_POSTGRESQL_COMPARE_H
+#define SQLPP_TESTS_POSTGRESQL_COMPARE_H
+
+#include <sqlpp11/postgresql/connection.h>
+
+#include <iostream>
+
+namespace
+{
+  template <typename Result, typename Expected>
+  void assert_equal(int lineNo, const Result& result, const Expected& expected)
+  {
+    if (result != expected)
+    {
+      std::cerr << __FILE__ << " " << lineNo << '\n'
+                << "Expected: -->|" << expected << "|<--\n"
+                << "Received: -->|" << result << "|<--\n";
+      throw std::runtime_error("unexpected result");
+    }
+  }
+
+  template <typename Expression>
+  void compare(int lineNo, const Expression& expr, const std::string& expected)
+  {
+    sqlpp::postgresql::connection connection;
+    sqlpp::postgresql::context_t printer{connection};
+
+    const auto result = serialize(expr, printer).str();
+
+    assert_equal(lineNo, result, expected);
+  }
+}  // namespace
+
+#endif

tests/sqlite3/CMakeLists.txt

@@ -22,4 +22,5 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+add_subdirectory(serialize)
 add_subdirectory(usage)

tests/sqlite3/serialize/CMakeLists.txt

@@ -0,0 +1,54 @@
+# Copyright (c) 2023, 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.
+
+set(test_files
+    Float.cpp
+)
+
+create_test_sourcelist(test_sources test_main.cpp ${test_files})
+
+add_executable(sqlpp11_sqlite3_serialize_tests ${test_sources})
+target_link_libraries(sqlpp11_sqlite3_serialize_tests PRIVATE sqlpp11_testing sqlpp11_sqlite3_testing)
+if (BUILD_SQLCIPHER_CONNECTOR)
+    target_link_libraries(sqlpp11_sqlite3_serialize_tests PRIVATE sqlpp11::sqlcipher)
+    if (SQLPP_DYNAMIC_LOADING)
+        target_include_directories(sqlpp11_sqlite3_serialize_tests PRIVATE ${SQLCIPHER_INCLUDE_DIRS})
+    endif()
+else()
+    target_link_libraries(sqlpp11_sqlite3_serialize_tests PRIVATE sqlpp11::sqlite3)
+endif()
+
+# conditionally bump to a higher C++ standard to test compatibility
+if (SQLPP11_TESTS_CXX_STD)
+    set_property(TARGET sqlpp11_sqlite3_serialize_tests PROPERTY CXX_STANDARD ${SQLPP11_TESTS_CXX_STD})
+    set_property(TARGET sqlpp11_sqlite3_serialize_tests PROPERTY CXX_STANDARD_REQUIRED ON)
+    set_property(TARGET sqlpp11_sqlite3_serialize_tests PROPERTY CXX_EXTENSIONS OFF)
+endif()
+
+foreach(test_file IN LISTS test_files)
+    get_filename_component(test ${test_file} NAME_WLE)
+    add_test(NAME sqlpp11.sqlite3.serialize.${test}
+        COMMAND sqlpp11_sqlite3_serialize_tests ${test}
+    )
+endforeach()

tests/sqlite3/serialize/Float.cpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2023, 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 <sqlpp11/data_types/floating_point.h>
+#include <sqlpp11/value.h>
+
+#include "compare.h"
+
+int Float(int, char*[])
+{
+  compare(__LINE__, sqlpp::value(10.0000114), "10.0000114");
+
+  return 0;
+}

tests/sqlite3/serialize/compare.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2013-2015, 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_TESTS_SQLITE3_COMPARE_H
+#define SQLPP_TESTS_SQLITE3_COMPARE_H
+
+#include <sqlpp11/sqlite3/connection.h>
+
+#include <iostream>
+
+namespace
+{
+  template <typename Result, typename Expected>
+  void assert_equal(int lineNo, const Result& result, const Expected& expected)
+  {
+    if (result != expected)
+    {
+      std::cerr << __FILE__ << " " << lineNo << '\n'
+                << "Expected: -->|" << expected << "|<--\n"
+                << "Received: -->|" << result << "|<--\n";
+      throw std::runtime_error("unexpected result");
+    }
+  }
+
+  template <typename Expression>
+  void compare(int lineNo, const Expression& expr, const std::string& expected)
+  {
+    sqlpp::sqlite3::connection_config config;
+    config.path_to_database = ":memory:";
+    config.flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
+    config.debug = true;
+    sqlpp::sqlite3::connection connection{config};
+    sqlpp::sqlite3::serializer_t printer{connection};
+
+    const auto result = serialize(expr, printer).str();
+
+    assert_equal(lineNo, result, expected);
+  }
+}  // namespace
+
+#endif