[ext] Embedded Template Library ETL

[rleh]

• Submodule of partial ETLCPP/etl repo: https://github.com/modm-ext/etl-partial
• lbuild module
• Minimal example
• Ignore profiles/ folder and doxygen.h
• ETL_ASSERT etc should be rerouted to modm_assert. I think replacing the error_handler.h file should be enough for that.
• Verify that all compatible ETL_* defined are defaulted, like ETL_CPP17_SUPPORTED etc.
• <etl_local.h> mechanism? => ETL uses etl_profile.h themselves.
• Add ETL as external project to Readme

[salkinium]

Hm, ETL is certainly very large, I was wondering if there's any way to modularize ETL just a little. Something along the lines of the documentation grouping: https://www.etlcpp.com/documentation.html That would allow us to use ETL inside modm without forcing a lot of file to be generated all the time. We don't have to do it right away, only when we want to start using ETL inside modm.

[TomSaw]

Waaa!! You're reading my thoughts. I've just scratched my head on how to get a python-like dict in C++ and here it is!

[kikass13]

I have also added etl to our modm repositories and we are keen on using it excessively 👍

don't forget to add the etl::string to your MODM_LOGGER class, so that we can print etl::strings as well! :)
I am using something like this for now

etl::string<255> etlStr{"xaxa"};
std::string str(etlStr.data(), etlStr.data_end());
MODM_LOG_INFO << str.c_str() << modm::endl;

which is awkward but fine, i guess :p

[salkinium]

@rleh is it possible to address my todo list above until the Q3 release in 10 days? I don't think we can modularize the library since they update their code so much…

[rleh]

Hopefully I'll find some time next week...

[salkinium]

We should probably have a better example.

[salkinium]

@rleh please review and test.

[rleh]

Approve ✅