[MISC] Use cpp23

.github/workflows/ci_linux.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11", "intel"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "intel"]
         include:
           - compiler: "intel"
             cxx_flags: "-fp-model=strict -Wno-overriding-option"

.github/workflows/ci_macos.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12"]
     steps:
       - name: Checkout
         uses: actions/checkout@v4

.github/workflows/ci_misc.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "gcc-14", "gcc-11", "intel"]
+        compiler: ["clang-19", "gcc-14", "gcc-12", "intel"]
         build: ["snippet", "performance", "header"]
         include:
           - compiler: "intel"

.github/workflows/cron_api.yml

@@ -32,7 +32,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["gcc-14", "gcc-13", "gcc-12", "gcc-11"]
+        compiler: ["gcc-14", "gcc-13", "gcc-12"]
     container:
       image: ghcr.io/seqan/${{ matrix.compiler }}
       volumes:

.github/workflows/cron_avx2.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11", "intel"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "intel"]
         build: [unit, snippet, performance, header]
         include:
           - compiler: "intel"

.github/workflows/cron_latest_libraries.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "gcc-11", "intel"]
+        compiler: ["clang-19", "clang-18", "clang-17", "gcc-14", "gcc-13", "gcc-12", "intel"]
         build: [unit, snippet, performance, header]
         include:
           - compiler: "intel"

cmake/package-lock.cmake

@@ -47,8 +47,7 @@ CPMDeclarePackage (googletest
                    VERSION ${SEQAN3_GOOGLETEST_VERSION}
                    GITHUB_REPOSITORY google/googletest
                    SYSTEM TRUE
-                   OPTIONS "BUILD_GMOCK OFF" "INSTALL_GTEST OFF" "CMAKE_CXX_STANDARD 20"
-                           "CMAKE_MESSAGE_LOG_LEVEL WARNING")
+                   OPTIONS "BUILD_GMOCK OFF" "INSTALL_GTEST OFF" "CMAKE_MESSAGE_LOG_LEVEL WARNING")
 # doxygen-awesome
 set (SEQAN3_DOXYGEN_AWESOME_VERSION 2.3.4)
 CPMDeclarePackage (doxygen_awesome

cmake/seqan3-config.cmake

@@ -44,17 +44,15 @@
 #   SEQAN3_INCLUDE_DIRS     -- to be passed to include_directories ()
 #   SEQAN3_LIBRARIES        -- to be passed to target_link_libraries ()
 #   SEQAN3_DEFINITIONS      -- to be passed to add_definitions ()
-#   SEQAN3_CXX_FLAGS        -- to be added to CMAKE_CXX_FLAGS
 #
 # Additionally, the following [IMPORTED][IMPORTED] targets are defined:
 #
 #   seqan3::seqan3          -- interface target where
 #                                  target_link_libraries(target seqan3::seqan3)
 #                              automatically sets
 #                                  target_include_directories(target $SEQAN3_INCLUDE_DIRS),
-#                                  target_link_libraries(target $SEQAN3_LIBRARIES),
-#                                  target_compile_definitions(target $SEQAN3_DEFINITIONS) and
-#                                  target_compile_options(target $SEQAN3_CXX_FLAGS)
+#                                  target_link_libraries(target $SEQAN3_LIBRARIES) and
+#                                  target_compile_definitions(target $SEQAN3_DEFINITIONS)
 #                              for a target.
 #
 #   [IMPORTED]: https://cmake.org/cmake/help/v3.10/prop_tgt/IMPORTED.html#prop_tgt:IMPORTED
@@ -201,53 +199,14 @@ option (SEQAN3_NO_BZIP2 "Don't use BZip2, even if present." OFF)
 # Check supported compilers
 # ----------------------------------------------------------------------------
 
-if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 10)
-    message (FATAL_ERROR "GCC < 10 is not supported. The detected compiler version is ${CMAKE_CXX_COMPILER_VERSION}.")
+if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12)
+    message (FATAL_ERROR "GCC < 12 is not supported. The detected compiler version is ${CMAKE_CXX_COMPILER_VERSION}.")
 endif ()
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 17)
     message (FATAL_ERROR "Clang < 17 is not supported. The detected compiler version is ${CMAKE_CXX_COMPILER_VERSION}.")
 endif ()
 
-# ----------------------------------------------------------------------------
-# Require C++20
-# ----------------------------------------------------------------------------
-
-set (CMAKE_REQUIRED_FLAGS_SAVE ${CMAKE_REQUIRED_FLAGS})
-
-set (CXXSTD_TEST_SOURCE
-     "#if !defined (__cplusplus) || (__cplusplus < 202002L)
-      #error NOCXX20
-      #endif
-      int main() {}")
-
-set (SEQAN3_FEATURE_CPP20_FLAG_BUILTIN "")
-set (SEQAN3_FEATURE_CPP20_FLAG_STD20 "-std=c++20")
-
-set (SEQAN3_CPP20_FLAG "")
-
-foreach (_FLAG BUILTIN STD20)
-    set (CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS_SAVE} ${SEQAN3_FEATURE_CPP20_FLAG_${_FLAG}}")
-
-    check_cxx_source_compiles ("${CXXSTD_TEST_SOURCE}" CPP20_FLAG_${_FLAG})
-
-    if (CPP20_FLAG_${_FLAG})
-        set (SEQAN3_CPP20_FLAG ${_FLAG})
-        break ()
-    endif ()
-endforeach ()
-
-set (CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE})
-
-if (SEQAN3_CPP20_FLAG STREQUAL "BUILTIN")
-    seqan3_config_print ("C++ Standard-20 support:    builtin")
-elseif (SEQAN3_CPP20_FLAG)
-    set (SEQAN3_CXX_FLAGS "${SEQAN3_CXX_FLAGS} ${SEQAN3_FEATURE_CPP20_FLAG_${SEQAN3_CPP20_FLAG}}")
-    seqan3_config_print ("C++ Standard-20 support:    via ${SEQAN3_FEATURE_CPP20_FLAG_${SEQAN3_CPP20_FLAG}}")
-else ()
-    seqan3_config_error ("SeqAn3 requires C++20, but your compiler does not support it.")
-endif ()
-
 # ----------------------------------------------------------------------------
 # thread support (pthread, windows threads)
 # ----------------------------------------------------------------------------
@@ -389,14 +348,18 @@ set (CXXSTD_TEST_SOURCE "#include <seqan3/core/platform.hpp>
 # using try_compile instead of check_cxx_source_compiles to capture output in case of failure
 file (WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx" "${CXXSTD_TEST_SOURCE}\n")
 
-try_compile (SEQAN3_PLATFORM_TEST #
+# cmake-format: off
+try_compile (SEQAN3_PLATFORM_TEST
              ${CMAKE_BINARY_DIR}
              ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx
-             CMAKE_FLAGS "-DCOMPILE_DEFINITIONS:STRING=${CMAKE_CXX_FLAGS} ${SEQAN3_CXX_FLAGS}"
-                         "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_INCLUDE_PATH};${SEQAN3_INCLUDE_DIR};${SEQAN3_DEPENDENCY_INCLUDE_DIRS}"
+             CMAKE_FLAGS "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_INCLUDE_PATH};${SEQAN3_INCLUDE_DIR};${SEQAN3_DEPENDENCY_INCLUDE_DIRS}"
              COMPILE_DEFINITIONS ${SEQAN3_DEFINITIONS}
              LINK_LIBRARIES ${SEQAN3_LIBRARIES}
+             CXX_STANDARD 23
+             CXX_STANDARD_REQUIRED ON
+             CXX_EXTENSIONS OFF
              OUTPUT_VARIABLE SEQAN3_PLATFORM_TEST_OUTPUT)
+# cmake-format: on
 
 if (SEQAN3_PLATFORM_TEST)
     seqan3_config_print ("SeqAn3 platform.hpp build:  passed.")
@@ -436,11 +399,9 @@ set (SEQAN3_INCLUDE_DIRS ${SEQAN3_INCLUDE_DIR} ${SEQAN3_DEPENDENCY_INCLUDE_DIRS}
 # ----------------------------------------------------------------------------
 
 if (SEQAN3_FOUND AND NOT TARGET seqan3::seqan3)
-    separate_arguments (SEQAN3_CXX_FLAGS_LIST UNIX_COMMAND "${SEQAN3_CXX_FLAGS}")
-
     add_library (seqan3_seqan3 INTERFACE)
     target_compile_definitions (seqan3_seqan3 INTERFACE ${SEQAN3_DEFINITIONS})
-    target_compile_options (seqan3_seqan3 INTERFACE ${SEQAN3_CXX_FLAGS_LIST})
+    target_compile_features (seqan3_seqan3 INTERFACE cxx_std_23)
     target_link_libraries (seqan3_seqan3 INTERFACE "${SEQAN3_LIBRARIES}")
     # include seqan3/include/ as -I, because seqan3 should never produce warnings.
     target_include_directories (seqan3_seqan3 INTERFACE "${SEQAN3_INCLUDE_DIR}")
@@ -467,7 +428,6 @@ if (SEQAN3_FIND_DEBUG)
     message ("  SEQAN3_INCLUDE_DIRS         ${SEQAN3_INCLUDE_DIRS}")
     message ("  SEQAN3_LIBRARIES            ${SEQAN3_LIBRARIES}")
     message ("  SEQAN3_DEFINITIONS          ${SEQAN3_DEFINITIONS}")
-    message ("  SEQAN3_CXX_FLAGS            ${SEQAN3_CXX_FLAGS}")
     message ("")
     message ("  SEQAN3_VERSION              ${SEQAN3_VERSION}")
     message ("  SEQAN3_VERSION_MAJOR        ${SEQAN3_VERSION_MAJOR}")

include/seqan3/argument_parser/validators.hpp

@@ -11,6 +11,7 @@
 
 #include <algorithm>
 #include <concepts>
+#include <exception>
 #include <filesystem>
 #include <fstream>
 #include <ranges>

include/seqan3/core/platform.hpp

@@ -40,7 +40,7 @@
  *
  * \sa https://sourceforge.net/p/predef/wiki/Compilers
  */
-#if defined(__GNUC__) && !defined(__llvm__) && !defined(__INTEL_COMPILER)
+#if defined(__GNUC__) && !defined(__llvm__) && !defined(__INTEL_COMPILER) && !defined(__INTEL_LLVM_COMPILER)
 #    define SEQAN3_COMPILER_IS_GCC 1
 #else
 #    define SEQAN3_COMPILER_IS_GCC 0
@@ -52,60 +52,43 @@
 #endif // SEQAN3_DOXYGEN_ONLY(1)0
 
 // ============================================================================
-//  Compiler support GCC
+//  Compiler support
 // ============================================================================
 
-#if SEQAN3_COMPILER_IS_GCC
-#    if (__GNUC__ < 11)
-#        error                                                                                                         \
-            "SeqAn 3.1.x is the last version that supports GCC 7, 8, and 9. SeqAn 3.2.x is the latest version that support GCC 10. Please upgrade your compiler or use 3.1.x./3.2.x."
-#    endif // (__GNUC__ < 11)
-
-#    if (__GNUC__ == 11 && __GNUC_MINOR__ <= 3)
-#        pragma GCC warning "Be aware that GCC < 11.4 might have bugs that cause SeqAn3 fail to compile."
-#    endif // (__GNUC__ == 11 && __GNUC_MINOR__ <= 2)
-
-#    if (__GNUC__ == 12 && __GNUC_MINOR__ <= 2)
-#        pragma GCC warning "Be aware that GCC < 12.3 might have bugs that cause SeqAn3 fail to compile."
-#    endif // (__GNUC__ == 12 && __GNUC_MINOR__ <= 1)
+#if SEQAN3_COMPILER_IS_GCC && (__GNUC__ < 12)
+#    error "At least GCC 12 is needed."
+#endif
 
-#    if SEQAN3_DOXYGEN_ONLY(1) 0
-//!\brief This disables the warning you would get if your compiler is newer than the latest supported version.
-#        define SEQAN3_DISABLE_NEWER_COMPILER_DIAGNOSTIC
-#    endif // SEQAN3_DOXYGEN_ONLY(1)0
+// clang-format off
+#if defined(__INTEL_LLVM_COMPILER) && (__INTEL_LLVM_COMPILER < 20240000)
+#    error "At least Intel OneAPI 2024 is needed."
+#endif
+// clang-format on
 
-#    ifndef SEQAN3_DISABLE_NEWER_COMPILER_DIAGNOSTIC
-#        if (__GNUC__ > 14)
-#            pragma message                                                                                            \
-                "Your compiler is newer than the latest supported compiler of this SeqAn version (gcc-13). It might be that SeqAn does not compile due to this. You can disable this warning by setting -DSEQAN3_DISABLE_NEWER_COMPILER_DIAGNOSTIC."
-#        endif // (__GNUC__ > 13)
-#    endif     // SEQAN3_DISABLE_NEWER_COMPILER_DIAGNOSTIC
+#if defined(__clang__) && defined(__clang_major__) && (__clang_major__ < 17)
+#    error "At least Clang 17 is needed."
+#endif
 
 // ============================================================================
-//  Compiler support Clang
+//  Standard library support
 // ============================================================================
 
-#elif defined(__clang__)
-#    if __clang_major__ < 17
-#        error "Only Clang >= 17 is supported."
-#    endif
-
-// ============================================================================
-//  Compiler support other
-// ============================================================================
+#if defined(_LIBCPP_VERSION) && (_LIBCPP_VERSION < 170000)
+#    error "At least libc++ 17 is required."
+#endif
 
-#elif !defined(SEQAN3_DISABLE_COMPILER_CHECK)
-#    error "Your compiler is not supported. You can disable this error by setting -DSEQAN3_DISABLE_COMPILER_CHECK."
-#endif // SEQAN3_COMPILER_IS_GCC
+#if defined(_GLIBCXX_RELEASE) && (_GLIBCXX_RELEASE < 12)
+#    error "At least libstdc++ 12 is needed."
+#endif
 
 // ============================================================================
 //  C++ standard and features
 // ============================================================================
 
 // C++ standard [required]
 #ifdef __cplusplus
-#    if (__cplusplus < 202002L)
-#        error "SeqAn3 requires C++20, make sure that you have set -std=c++20."
+#    if (__cplusplus < 202100)
+#        error "SeqAn3 requires C++23, make sure that you have set -std=c++23."
 #    endif
 #else
 #    error "This is not a C++ compiler."

include/seqan3/io/stream/detail/fast_ostreambuf_iterator.hpp

@@ -11,6 +11,7 @@
 #pragma once
 
 #include <algorithm>
+#include <array>
 #include <cassert>
 #include <iterator>
 #include <ranges>

test/external_project/seqan3_setup_tutorial_with_sharg/CMakeLists.txt

@@ -19,6 +19,8 @@ list (APPEND CMAKE_PREFIX_PATH "${SHARG_ROOT}/build_system")
 cmake_minimum_required (VERSION 3.20...3.31)
 project (seqan3_tutorial CXX)
 
+set (CMAKE_CXX_STANDARD 23)
+
 # add seqan3 to search path
 list (APPEND CMAKE_PREFIX_PATH "${CMAKE_CURRENT_SOURCE_DIR}/../seqan3/cmake")
 # add the Sharg Parser to search path

test/external_project/seqan3_setup_tutorial_with_sharg_installed/CMakeLists.txt

@@ -9,6 +9,8 @@ project (seqan3_app CXX)
 include (../find-package-diagnostics.cmake)
 # ---
 
+set (CMAKE_CXX_STANDARD 23)
+
 # require seqan3 with a version between >=3.0.0 and <4.0.0
 find_package (seqan3 3.0 REQUIRED)
 find_package (sharg 1.0 REQUIRED)

test/seqan3-test.cmake

@@ -6,6 +6,18 @@
 # SeqAn3. To build tests, run cmake on one of the sub-folders in this directory
 # which contain a CMakeLists.txt.
 
+if (NOT DEFINED CMAKE_CXX_STANDARD)
+    set (CMAKE_CXX_STANDARD 23)
+endif ()
+
+if (NOT DEFINED CMAKE_CXX_STANDARD_REQUIRED)
+    set (CMAKE_CXX_STANDARD_REQUIRED ON)
+endif ()
+
+if (NOT DEFINED CMAKE_CXX_EXTENSIONS)
+    set (CMAKE_CXX_EXTENSIONS OFF)
+endif ()
+
 # require SeqAn3 package
 find_package (SeqAn3 REQUIRED HINTS ${CMAKE_CURRENT_LIST_DIR}/../cmake)