Switch to the {fmt} formatting library

I suggest to switch usage of printf (stdio) and cout (iostream) to the {fmt} library, which is the basis of C++20 new format functionalities. It is lightweight and fast (actually even more than stdio or streams), and is part of the C++20 standard (only a namespace change will be required!).

Another benefit is to avoid introducing and disseminate custom formatting code and util functions in the code base.

MR !77 (merged) already integrates the fmt library.

This issue is here to incitate every contributor to switch to {fmt} in their code.

added LanguageC++ PirorityLow + 1 deleted label

changed the description

As the code is in C++14, the library used is not the standard library (like it would be for c++20) but <fmt/range.h> or <fmt/format.h> from the external library fmt. Is there no problem with creating a new dependence for aidge_core to an external library?

I thought of it, as this bothered me too. But eventually, I think it would be fine:

• fmt can be fetched directly from git with the CMake FetchContent_MakeAvailable mechanism. No additional system dependency is required;
• It can be used as a header only library, thus making it practically invisible (no additional shared object). It is therefore not that different than other header-only functions we already embed in Aidge for supporting other C++XX features (e.g. span, any...);
• It supports many compilers, including cross-compilers for embedded HW (e.g. TI). Probably more than we will ever support;
• Exceptions can be disabled, as this is a requirement of Aidge (no very well enforced for now...).

@olivierbichler !77 (merged) introduces the use of fmt right ?

Is it enough to close this issue once the MR is merged ?

!77 (merged) remove all usage of printf, however, graph matching still uses streams @vincentlorrain.

TODO update the corresponding wiki section https://gitlab.eclipse.org/groups/eclipse/aidge/-/wikis/Error%20handling

mentioned in merge request !90 (merged)

closed