logical changes backported from:
https://github.com/kovidgoyal/calibre/commit/a3d3d8d33e314ccabb5099e78e4056a79b7c9aa2
https://bugs.gentoo.org/936270

diff -rup a/setup/build.py b/setup/build.py
--- a/setup/build.py	2022-06-17 04:35:27.000000000 +0200
+++ b/setup/build.py	2024-07-19 11:51:56.374389213 +0200
@@ -65,6 +65,8 @@ class Extension:
                     self.cflags.insert(0, '-std=c++11')
                 elif kwargs.get('needs_c++14'):
                     self.cflags.insert(0, '-std=c++14')
+                elif kwargs.get('needs_c++17'):
+                    self.cflags.insert(0, '-std=c++17')
             else:
                 if kwargs.get('needs_c99'):
                     self.cflags.insert(0, '-std=c99')
diff -rup a/setup/extensions.json b/setup/extensions.json
--- a/setup/extensions.json	2022-06-17 04:35:27.000000000 +0200
+++ b/setup/extensions.json	2024-07-19 11:52:11.253389395 +0200
@@ -75,7 +75,7 @@
         "name": "sqlite_extension",
         "headers": "calibre/utils/cpp_binding.h",
         "sources": "calibre/db/sqlite_extension.cpp",
-		"needs_c++14": true,
+		"needs_c++17": true,
         "libraries": "icudata icui18n icuuc icuio stemmer",
         "windows_libraries": "icudt icuin icuuc icuio libstemmer",
         "lib_dirs": "!icu_lib_dirs",