Updates most of the files for optional use of the new cpp features.

Author: TheSharpOwl

CMakeLists.txt

@@ -16,6 +16,8 @@ set(CPPKAFKA_VERSION "${CPPKAFKA_VERSION_MAJOR}.${CPPKAFKA_VERSION_MINOR}.${CPPK
 set(RDKAFKA_MIN_VERSION "0.9.4")
 set(RDKAFKA_MIN_VERSION_HEX 0x00090400)
 
+option(USE_CPP17 "Use C++17 features instead of Boost (still, if you don't have boost you can't build examples" OFF)
+
 if (NOT CMAKE_CXX_FLAGS)
     # Set default compile flags for the project
     if(MSVC)
@@ -31,8 +33,13 @@ if (NOT CMAKE_CXX_FLAGS)
         set(CMAKE_CXX_FLAGS "-Wall")
     endif()
 endif()
-# Use C++17
-set(CMAKE_CXX_STANDARD 17)
+
+if(USE_CPP17)
+    set(CMAKE_CXX_STANDARD 17)
+    add_definitions("-D_USE_CPP17")
+else()
+    set(CMAKE_CXX_STANDARD 11)
+endif()
 
 # Set output directories
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/lib)
@@ -104,32 +111,11 @@ if (NOT CPPKAFKA_PKGCONFIG_DIR)
     set(CPPKAFKA_PKGCONFIG_DIR share/pkgconfig)
 endif()
 
-# Try to find the RdKafka configuration file if present.
-# This will search default system locations as well as RdKafka_ROOT and RdKafka_Dir paths if specified.
-find_package(RdKafka ${FIND_PACKAGE_QUIET} CONFIG)
-set(RDKAFKA_TARGET_IMPORTS ${RdKafka_FOUND})
-if (NOT RdKafka_FOUND)
-    message(STATUS "RdKafkaConfig.cmake not found. Attempting to find module instead...")
-    find_package(RdKafka REQUIRED ${FIND_PACKAGE_QUIET} MODULE)
-    if (NOT RdKafka_FOUND)
-        message(FATAL_ERROR "RdKafka module not found. Please set RDKAFKA_ROOT to the install path or RDKAFKA_DIR pointing to the RdKafka configuration file location.")
-    else()
-        message(STATUS "RdKafka module found.")
-    endif()
-else()
-    message(STATUS "RdKafka configuration file found: ${RdKafka_CONFIG}")
-endif()
-
-add_subdirectory(src)
-add_subdirectory(include/cppkafka)
-
-# Examples target
-if (NOT CPPKAFKA_DISABLE_EXAMPLES)
+if(NOT USE_CPP17 OR NOT CPPKAFKA_DISABLE_EXAMPLES OR NOT CPPKAFKA_DISABLE_TESTS)
     # Look for Boost (just need boost.optional headers here)
-    find_package(Boost ${FIND_PACKAGE_QUIET} CONFIG)
+    find_package(Boost REQUIRED ${FIND_PACKAGE_QUIET})
+
     if (Boost_FOUND)
-        option(CPPKAFKA_BOOST_STATIC_LIBS "Link with Boost static libraries." ON)
-        option(CPPKAFKA_BOOST_USE_MULTITHREADED "Use Boost multithreaded libraries." ON)
         find_package(Boost COMPONENTS program_options ${FIND_PACKAGE_QUIET})
         set(Boost_USE_STATIC_LIBS ${CPPKAFKA_BOOST_STATIC_LIBS})
         set(Boost_USE_MULTITHREADED ${CPPKAFKA_BOOST_USE_MULTITHREADED})
@@ -142,12 +128,37 @@ if (NOT CPPKAFKA_DISABLE_EXAMPLES)
             message(STATUS "Boost is multi-threaded: ${CPPKAFKA_BOOST_USE_MULTITHREADED}")
             message(STATUS "Boost libraries: ${Boost_LIBRARIES}")
         endif()
+    endif()
+
+    # Examples target
+    if (Boost_PROGRAM_OPTIONS_FOUND)
         add_subdirectory(examples)
     else()
         message(STATUS "Disabling examples")
     endif()
 endif()
 
+# Try to find the RdKafka configuration file if present.
+# This will search default system locations as well as RdKafka_ROOT and RdKafka_Dir paths if specified.
+find_package(RdKafka ${FIND_PACKAGE_QUIET} CONFIG)
+set(RDKAFKA_TARGET_IMPORTS ${RdKafka_FOUND})
+if (NOT RdKafka_FOUND)
+    message(STATUS "RdKafkaConfig.cmake not found. Attempting to find module instead...")
+    find_package(RdKafka REQUIRED ${FIND_PACKAGE_QUIET} MODULE)
+    if (NOT RdKafka_FOUND)
+        message(FATAL_ERROR "RdKafka module not found. Please set RDKAFKA_ROOT to the install path or RDKAFKA_DIR pointing to the RdKafka configuration file location.")
+    else()
+        message(STATUS "RdKafka module found.")
+    endif()
+else()
+    message(STATUS "RdKafka configuration file found: ${RdKafka_CONFIG}")
+endif()
+
+add_subdirectory(src)
+add_subdirectory(include/cppkafka)
+
+
+
 # Add a target to generate API documentation using Doxygen
 find_package(Doxygen ${FIND_PACKAGE_QUIET})
 if(DOXYGEN_FOUND)
@@ -188,4 +199,4 @@ if(NOT TARGET uninstall)
     # Add uninstall target
     add_custom_target(uninstall
         COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake)
-endif()
+endif()

include/cppkafka/configuration.h

@@ -35,7 +35,7 @@
 #include <functional>
 #include <initializer_list>
 #include <chrono>
-#include <optional>
+#include "utils/optional.h"
 #include <librdkafka/rdkafka.h>
 #include "topic_partition_list.h"
 #include "topic_configuration.h"
@@ -226,12 +226,12 @@ class CPPKAFKA_API Configuration : public ConfigurationBase<Configuration> {
     /**
      * Gets the default topic configuration
      */
-    const std::optional<TopicConfiguration>& get_default_topic_configuration() const;
+    const cppkafka::optional<TopicConfiguration>& get_default_topic_configuration() const;
 
     /**
      * Gets the default topic configuration
      */
-    std::optional<TopicConfiguration>& get_default_topic_configuration();
+    cppkafka::optional<TopicConfiguration>& get_default_topic_configuration();
 private:
     using HandlePtr = ClonablePtr<rd_kafka_conf_t, decltype(&rd_kafka_conf_destroy),
                                   decltype(&rd_kafka_conf_dup)>;
@@ -240,7 +240,7 @@ class CPPKAFKA_API Configuration : public ConfigurationBase<Configuration> {
     static HandlePtr make_handle(rd_kafka_conf_t* ptr);
 
     HandlePtr handle_;
-    std::optional<TopicConfiguration> default_topic_config_;
+    cppkafka::optional<TopicConfiguration> default_topic_config_;
     DeliveryReportCallback delivery_report_callback_;
     OffsetCommitCallback offset_commit_callback_;
     ErrorCallback error_callback_;

include/cppkafka/cppkafka.h

@@ -57,11 +57,13 @@
 #include <cppkafka/topic_configuration.h>
 #include <cppkafka/topic_partition.h>
 #include <cppkafka/topic_partition_list.h>
+#include <cppkafka/utils/any.h>
 #include <cppkafka/utils/backoff_committer.h>
 #include <cppkafka/utils/backoff_performer.h>
 #include <cppkafka/utils/buffered_producer.h>
 #include <cppkafka/utils/compacted_topic_processor.h>
 #include <cppkafka/utils/consumer_dispatcher.h>
+#include <cppkafka/utils/optional.h>
 #include <cppkafka/utils/poll_interface.h>
 #include <cppkafka/utils/poll_strategy_base.h>
 #include <cppkafka/utils/roundrobin_poll_strategy.h>

include/cppkafka/message.h

@@ -34,8 +34,8 @@
 #include <cstdint>
 #include <chrono>
 #include <cassert>
-#include <optional>
 #include <librdkafka/rdkafka.h>
+#include "utils/optional.h"
 #include "buffer.h"
 #include "macros.h"
 #include "error.h"
@@ -189,7 +189,7 @@ class CPPKAFKA_API Message {
      *
      * If calling rd_kafka_message_timestamp returns -1, then boost::none_t will be returned.
      */
-    std::optional<MessageTimestamp> get_timestamp() const;
+    cppkafka::optional<MessageTimestamp> get_timestamp() const;
 
 #if RD_KAFKA_VERSION >= RD_KAFKA_MESSAGE_LATENCY_SUPPORT_VERSION
     /**

include/cppkafka/utils/compacted_topic_processor.h

@@ -34,7 +34,7 @@
 #include <string>
 #include <map>
 #include <set>
-#include<optional>
+#include"optional.h"
 #include "../buffer.h"
 #include "../consumer.h"
 #include "../macros.h"
@@ -106,8 +106,8 @@ class CPPKAFKA_API CompactedTopicEvent {
     EventType type_;
     std::string topic_;
     int partition_;
-    std::optional<Key> key_;
-    std::optional<Value> value_;
+    cppkafka::optional<Key> key_;
+    cppkafka::optional<Value> value_;
 };
 
 template <typename Key, typename Value>
@@ -121,12 +121,12 @@ class CPPKAFKA_API CompactedTopicProcessor {
     /**
      * Callback used for decoding key objects
      */
-    using KeyDecoder = std::function<std::optional<Key>(const Buffer&)>;
+    using KeyDecoder = std::function<cppkakfa::optional<Key>(const Buffer&)>;
 
     /**
      * Callback used for decoding value objects
      */
-    using ValueDecoder = std::function<std::optional<Value>(const Key& key, const Buffer&)>;
+    using ValueDecoder = std::function<cppkafka::optional<Value>(const Key& key, const Buffer&)>;
 
     /**
      * Callback used for event handling
@@ -276,10 +276,10 @@ void CompactedTopicProcessor<Key, Value>::process_event() {
     Message message = consumer_.poll();
     if (message) {
         if (!message.get_error()) {
-            std::optional<Key> key = key_decoder_(message.get_key());
+            cppkafka::optional<Key> key = key_decoder_(message.get_key());
             if (key) {
                 if (message.get_payload()) {
-                    std::optional<Value> value = value_decoder_(*key, message.get_payload());
+                    cppkafka::optional<Value> value = value_decoder_(*key, message.get_payload());
                     if (value) {
                         // If there's a payload and we managed to parse the value, generate a
                         // SET_ELEMENT event

include/cppkafka/utils/poll_strategy_base.h

@@ -31,7 +31,7 @@
 #define CPPKAFKA_POLL_STRATEGY_BASE_H
 
 #include <map>
-#include <any>
+#include "any.h"
 #include "../queue.h"
 #include "../topic_partition_list.h"
 #include "poll_interface.h"
@@ -45,7 +45,7 @@ namespace cppkafka {
  */
 struct QueueData {
     Queue       queue;
-    std::any  metadata;
+    cppkafka::any  metadata;
 };
 
 /**

src/CMakeLists.txt

@@ -49,7 +49,7 @@ set_target_properties(${TARGET_NAME} PROPERTIES
 # In CMake >= 3.15 Boost::boost == Boost::headers
 target_link_libraries(${TARGET_NAME} PUBLIC RdKafka::rdkafka)
 
-if(NOT CPPKAFKA_DISABLE_EXAMPLES)
+if(NOT USE_CPP17 OR NOT CPPKAFKA_DISABLE_EXAMPLES OR NOT CPPKAFKA_DISABLE_TESTS)
     target_link_libraries(${TARGET_NAME} PUBLIC Boost::boost)
 endif()
 

src/configuration.cpp

@@ -41,7 +41,7 @@ using std::move;
 using std::vector;
 using std::initializer_list;
 using std::chrono::milliseconds;
-using std::optional;
+using cppkafka::optional;
 
 namespace cppkafka {