How to use a C++ class in main.c

What instructions do you follow to implement a C++ class and use it in "main.c"?
Suppose it's a simple project, like blinking the LED.

[Andrew Neil]

Once you've got the tools set up to build C++, it should be no different to mixing C and C++ in any other context...

https://isocpp.org/wiki/faq/mixing-c-and-cpp

https://stackoverflow.com/questions/4025869/using-mixing-c-in-c-code

 

[Andrew Neil]

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@Andrew Neil wrote:

no different to mixing C and C++ in any other context...

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As @TDK said, you can't ever use C++ classes in C files - the C language has no concept of classes.

It's the (a?) key thing which C++ adds and C does not have.

This has nothing to do with ST or STM32 or CubeIDE - it is a fundamental limitation of the language.

 

But, as @TDK and @Ozone, you can call C functions and access C data from C++

[Ozone]

I think at this point it's too late.

You would need to create a C++ project, which would name the file "main.cpp".
It works the other way around, C++ can call standard C code.

Neither does the C startup code come with constructors/desctructors, nor does the linker deal well with name mangling issues.

[TDK]

You can't use classes in C files. If you want to use a class/object, it must be called from a C++ file.

I wish ST provided us with a "main.cpp" and C++ versions of the libraries when we selected C++ as the target language. 

[Ozone]

First, I don't use CubeIDE, nor Cube/HAL code.

But the IDE / toolchain can handle C++ projects as well as C ones', just create new projects as such.
The proper compiler/linker settings and startup code will be automatically selected.

> ...and C++ versions of the libraries ...

You can use "C code" libraries in C++, although you lose the C++ specific advantages.
Why there are no cpp libraries and most (if not all) examples are plain C, you would need to ask ST ...

[Andrew Neil]

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@Ozone wrote:

Why there are no cpp libraries and most (if not all) examples are plain C, you would need to ask ST ...

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Demand, I guess - or lack thereof.

[TDK]

I use C++ pretty exclusively for programming micros, and I keep main.c named main.c, and everything works fine.

Choose how to go downstream but don't fight the current. There are no showstoppers using C++ in the current CubeMX framework. main.h can be included if you need access to variables, and it has the __cplusplus guards.

[Pavel A.]

C++ was lacking some useful features of C (for one, designated initializers) but newest C++ standard is going to make C++ a complete superset of C. When this happens, c++ will go mainstream in embedded. But even then... ants, cockroaches, sharks, crocodiles still exist and may outlast fancy creations. Long live C23.

By the way, the new AI-assisted Mojo language compiles native code for heterogeneous systems (like, CPU + GPU) and this is going to become a killer. Not Rust, sorry Microsoft.