From 025738c242e8a3420660b694842274be5a78bb8a Mon Sep 17 00:00:00 2001
From: Svenja Mehringer <svenja.mehringer@fu-berlin.de>
Date: Mon, 14 Mar 2022 09:17:15 +0100
Subject: [PATCH] [MISC] Drop GCC9 support.

---
 .github/workflows/ci_linux.yml |  6 ------
 .github/workflows/ci_misc.yml  | 22 ++++------------------
 doc/about/api/index.md         |  2 +-
 include/sharg/concept.hpp      |  2 +-
 include/sharg/validators.hpp   |  5 ++---
 5 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/.github/workflows/ci_linux.yml b/.github/workflows/ci_linux.yml
index b5d5cede..564d3683 100644
--- a/.github/workflows/ci_linux.yml
+++ b/.github/workflows/ci_linux.yml
@@ -43,12 +43,6 @@ jobs:
             cc: "gcc-10"
             build_type: Release
 
-          - name: "Unit gcc9 (c++2a)"
-            cxx: "g++-9"
-            cc: "gcc-9"
-            build_type: Release
-            cxx_flags: "-std=c++2a"
-
     steps:
       - name: Checkout
         uses: actions/checkout@v2
diff --git a/.github/workflows/ci_misc.yml b/.github/workflows/ci_misc.yml
index cd6c9456..a88003d6 100644
--- a/.github/workflows/ci_misc.yml
+++ b/.github/workflows/ci_misc.yml
@@ -28,14 +28,14 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - name: "Snippet gcc9"
-            cxx: "g++-9"
-            cc: "gcc-9"
+          - name: "Snippet gcc11"
+            cxx: "g++-11"
+            cc: "gcc-11"
             build: snippet
             build_type: Release
             build_threads: 2
             test_threads: 1 # snippets create and delete files and some separate tests create/delete the same files
-            cxx_flags: "-std=c++2a"
+            cxx_flags: "-std=c++20"
             cmake: 3.10.3
             requires_toolchain: true
             requires_ccache: true
@@ -55,20 +55,6 @@ jobs:
             skip_build_tests: false
             skip_run_tests: false
 
-          - name: "Header gcc9"
-            cxx: "g++-9"
-            cc: "gcc-9"
-            build: header
-            build_type: Debug
-            build_threads: 2
-            test_threads: 2
-            cxx_flags: "-std=c++2a"
-            cmake: 3.10.3
-            requires_toolchain: true
-            requires_ccache: true
-            skip_build_tests: false
-            skip_run_tests: false
-
           - name: "Documentation"
             build: documentation
             build_threads: 2
diff --git a/doc/about/api/index.md b/doc/about/api/index.md
index 26d9e816..a13dbfc4 100644
--- a/doc/about/api/index.md
+++ b/doc/about/api/index.md
@@ -22,7 +22,7 @@ For details regarding API stability, please see the
 The main requirement for Sharg is that your operating system provides one of the compilers supported by us.
 In general, we only support the latest three major compiler versions.
 We currently support the following compilers on 64-bit operating systems with little-endian CPU architectures:
-  * GCC9, GCC10, GCC11
+  * GCC10, GCC11
 
 \note Only the most recent minor release of a compiler is guaranteed to be supported, e.g. when `gcc-10.4` is released,
 we may drop support for `gcc-10.3`. Since all platforms with an older version receive minor release updates,
diff --git a/include/sharg/concept.hpp b/include/sharg/concept.hpp
index 8dc46fce..bbbe457c 100644
--- a/include/sharg/concept.hpp
+++ b/include/sharg/concept.hpp
@@ -12,7 +12,7 @@
 
 #pragma once
 
-#include <seqan3/std/concepts>
+#include <concepts>
 
 #include <sharg/enumeration_names.hpp>
 
diff --git a/include/sharg/validators.hpp b/include/sharg/validators.hpp
index 72209cf4..f22c680d 100644
--- a/include/sharg/validators.hpp
+++ b/include/sharg/validators.hpp
@@ -12,12 +12,11 @@
 
 #pragma once
 
+#include <concepts>
 #include <fstream>
+#include <ranges>
 #include <regex>
 
-#include <seqan3/std/concepts>
-#include <seqan3/std/ranges>
-
 #include <sharg/detail/safe_filesystem_entry.hpp>
 #include <sharg/detail/to_string.hpp>
 #include <sharg/exceptions.hpp>