fix 3.0 compile error

.github/workflows/linux.yml

@@ -23,36 +23,16 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-20.04]
-        compiler: [clang-6, clang-10-libc++, gcc-7, gcc-8, gcc-9]
+        compiler: [clang-10-libc++]
         ssl: [ssl_ON, ssl_OFF]
         dependencies: [dependencies_BUILT_IN]
 
         include:
-        - compiler: clang-6
-          COMPILER_INSTALL: clang-6.0 libc++-dev
-          C_COMPILER: clang-6.0
-          CXX_COMPILER: clang++-6.0
-
         - compiler: clang-10-libc++
           COMPILER_INSTALL: clang-10 libc++-dev
           C_COMPILER: clang-10
           CXX_COMPILER: clang++-10
 
-        - compiler: gcc-7
-          COMPILER_INSTALL: gcc-7 g++-7
-          C_COMPILER: gcc-7
-          CXX_COMPILER: g++-7
-
-        - compiler: gcc-8
-          COMPILER_INSTALL: gcc-8 g++-8
-          C_COMPILER: gcc-8
-          CXX_COMPILER: g++-8
-
-        - compiler: gcc-9
-          COMPILER_INSTALL: gcc-9 g++-9
-          C_COMPILER: gcc-9
-          CXX_COMPILER: g++-9
-
         - ssl: ssl_ON
           SSL_CMAKE_OPTION: -D WITH_OPENSSL=ON
 

.github/workflows/windows_mingw.yml

@@ -25,7 +25,6 @@ env:
   BUILD_TYPE: Release
   CLICKHOUSE_USER: clickhouse_cpp_cicd
   CLICKHOUSE_PASSWORD: clickhouse_cpp_cicd
-
   #
   # CLICKHOUSE_HOST: localhost
   # CLICKHOUSE_PORT: 9000

CMakeLists.txt

@@ -2,7 +2,7 @@ CMAKE_MINIMUM_REQUIRED (VERSION 3.5.2)
 
 LIST (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
-INCLUDE (cpp17)
+INCLUDE (cpp20)
 INCLUDE (subdirs)
 INCLUDE (openssl)
 INCLUDE (version)
@@ -24,7 +24,7 @@ PROJECT (CLICKHOUSE-CLIENT
     DESCRIPTION "ClickHouse C++ client library"
 )
 
-USE_CXX17 ()
+USE_CXX20 ()
 USE_OPENSSL ()
 
 IF (CLICKHOUSE_CPP_CHECK_VERSION)

clickhouse/CMakeLists.txt

@@ -45,8 +45,8 @@ SET ( clickhouse-cpp-lib-src
     base/singleton.h
     base/socket.h
     base/sslsocket.h
-    base/string_utils.h
-    base/string_view.h
+
+
     base/uuid.h
     base/wire_format.h
 
@@ -61,7 +61,7 @@ SET ( clickhouse-cpp-lib-src
     columns/ip6.h
     columns/itemview.h
     columns/lowcardinality.h
-    columns/lowcardinalityadaptor.h
+
     columns/map.h
     columns/nothing.h
     columns/nullable.h
@@ -86,8 +86,6 @@ SET ( clickhouse-cpp-lib-src
 if (MSVC)
     add_definitions(-D_CRT_SECURE_NO_WARNINGS)
     add_compile_options(/W4)
-    # remove in 3.0
-    add_compile_options(/wd4996)
 else()
     set(cxx_extra_wall "-Wempty-body -Wconversion -Wreturn-type -Wparentheses -Wuninitialized -Wunreachable-code -Wunused-function -Wunused-value -Wunused-variable")   
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${cxx_extra_wall}")

clickhouse/base/compressed.cpp

@@ -27,11 +27,7 @@ CompressedInput::CompressedInput(InputStream* input)
 
 CompressedInput::~CompressedInput() {
     if (!mem_.Exhausted()) {
-#if __cplusplus < 201703L
-        if (!std::uncaught_exception()) {
-#else
         if (!std::uncaught_exceptions()) {
-#endif
             throw LZ4Error("some data was not read");
         }
     }

clickhouse/client.cpp

@@ -621,9 +621,6 @@ bool Client::Impl::ReadBlock(InputStream& input, Block* block) {
         return false;
     }
 
-    CreateColumnByTypeSettings create_column_settings;
-    create_column_settings.low_cardinality_as_wrapped_column = options_.backward_compatibility_lowcardinality_as_wrapped_column;
-
     for (size_t i = 0; i < num_columns; ++i) {
         std::string name;
         std::string type;
@@ -634,7 +631,7 @@ bool Client::Impl::ReadBlock(InputStream& input, Block* block) {
             return false;
         }
 
-        if (ColumnRef col = CreateColumnByType(type, create_column_settings)) {
+        if (ColumnRef col = CreateColumnByType(type)) {
             if (num_rows && !col->Load(&input, num_rows)) {
                 throw ProtocolError("can't load column '" + name + "' of type " + type);
             }

clickhouse/client.h

@@ -117,15 +117,6 @@ struct ClientOptions {
     DECLARE_FIELD(connection_recv_timeout, std::chrono::milliseconds, SetConnectionRecvTimeout, std::chrono::milliseconds(0));
     DECLARE_FIELD(connection_send_timeout, std::chrono::milliseconds, SetConnectionSendTimeout, std::chrono::milliseconds(0));
 
-    /** It helps to ease migration of the old codebases, which can't afford to switch
-    * to using ColumnLowCardinalityT or ColumnLowCardinality directly,
-    * but still want to benefit from smaller on-wire LowCardinality bandwidth footprint.
-    *
-    * @see LowCardinalitySerializationAdaptor, CreateColumnByType
-    */
-    [[deprecated("Makes implementation of LC(X) harder and code uglier. Will be removed in next major release (3.0) ")]]
-    DECLARE_FIELD(backward_compatibility_lowcardinality_as_wrapped_column, bool, SetBakcwardCompatibilityFeatureLowCardinalityAsWrappedColumn, false);
-
     /** Set max size data to compress if compression enabled.
      *
      *  Allows choosing tradeoff between RAM\CPU: