Possible to use C++20 for ESP32 with Arduino framework

Development Platforms
, ,
1

I would like to use C++20, especially concepts when developing for ESP32 with Arduino framework, but I haven’t got it to compile. I tried with plain idf.py and it worked and as espressif says in their docs " By default, ESP-IDF compiles C++ code with C++23 language standard with GNU extensions (-std=gnu++23).".

So I’m wondering why it’s not working with platformio? I have just updated platformio so the compilers it provides should be up to date. Also the arduino framework shouldn’t be the limiting factor of c++ standard, since standard are backward compatible.

2

You can enable c++20 support by

build_flags=
  -std=gnu++2a
build_unflags=
  -std=gnu++11

However, this does not change the fact that Espressif’s xtensa-esp32-toolchain is missing the concepts header file :cry:

3

Consepts are available by default if I use esp-idf as the framework in platformio. Why is that? Why using arduino framework limits the compiler version?

EDIT:
Compiling with framework=arduino the toolchain used is toolchain-xtensa-esp32 @ 8.4.0+2021r2-patch5
Compiling with framework=esp-idf the toolchain used is toolchain-xtensa-esp32 @ 12.2.0+20230208

So when using arduino framework platformio chooses to use older compiler version. Do you know if it’s possible to force specific compiler version?

4

Espressif is currently working on Arduino version 3.0.
This will then be based on ESP-IDF 5.x and therefore also use the newer tool chain.

1 Like
5

You can get the 12.2.0 toolchain and Arduino-ESP32 3.x by using Jason’s platform fork.

https://github.com/platformio/platform-espressif32/issues/1211

1 Like