Arduino can be built with C20/C++20 or C17/C++17 by switching to the latest gcc-arm-none-eabi. Below shows 2 different ways one using arduino-cli and the other using a Makefile included in this repo.

This is the simplest buildable example made to be used as a template for new projects running Arduino-esp32 as an ESP-IDF component. See Arduino-esp32 in ESP Registry. To create a ESP-IDF project from ...