[KDESKTOP-968] applied c++20 style and new features

herve-er commented 2 months ago

This PR aims to do a first pass of refactoring to applied c++20 recommended style to our code base.

herve-er commented 2 months ago

This PR intentionally does not include any conversion to std::format. see : Jira 🎫

Clang has been updated to include support for nearly all C++20 features (almost all according to C++ compiler support - cppreference.com ). On macOS, we currently use the latest version of Xcode. However, we're limited by the support of macOS 10.15, which has been deprecated since September 12, 2022. Features like std::format and possibly other C++20 utilities require at least macOS 13.3. Since macOS 12 will be deprecated around November 1, 2024, it would be beneficial to update our supported macOS version at that time.