No. If C++ were a great language those C coders would have moved over in an instant. One of the advantages of looking at C code is that you can actually figure out in your head what the assembly will look like.
> you can actually figure out in your head what the assembly will look like
I keep hearing this, and I don't buy it. Did you know that `gcc -O3` will turn `int add(int x, int y) { return a + b; }` into an `lea` instruction? I doubt many people do.
And it's not like the compiler will magically switch to emitting different instructions if you compile the code above as C++...
Also, C++ uses a lot more memory, which can also be a no-go when you get as little as 32kb for code+data, luckily with in-place execution.
Depends on how you use it. "If you don't use it, you don't pay for it" is the C++ philosophy. If you use it as "C with objects", it should use no more memory than C with structs. If you use it as "C with polymorphism", it should use no more memory than C with function pointers.
CppCon 2016: Jason Turner “Rich Code for Tiny Computers: A Simple Commodore 64 Game in C++17”
Never cared for C beyond using it in Turbo C 2.0 for MS-DOS, and later when required to use it for university projects and client projects that explicitly required ANSI C89.
So it wasn't 64 KB, but it was perfectly usable on 640 KB systems.
The main problem has always been fighting misconceptions.
Uh. That's a pretty obvious one.
Sometimes using address generation ports is preferable to ALU ports.
Also 'lea' can load the result in a different register from both operands, 'add' will always need to modify a register.
People have been using 'lea' for calculations since dawn of time, for example:
shl ebx, 6
lea edi, [ebx*4 + ebx + 0xa0000]
add edi, eax
This was a common way in DOS days for calculating pixel address in mode 0x13.
One can do this with most C++ too. Though admittedly, non-tree virtual inheritance hierarchies, as well as member function pointers [et al] make this harder to achieve universally. I will also admit that it's easier to do with C.
If the optimizer gets its hands on either though, you may be in for a surprise no matter your choice.
In any case, C++ is copy-paste compatible with 99% of C89. So same benefits apply when using that subset.
It is plain language religion as observed at a few C++ conference talks.
The world moved from C++ to Java on the enterprise side back in the late 1990's. Why? Java was arguably faster and easier to develop in, even though many thought (including me) that C++ was technically a better language.
CppCon 2016: Dan Saks “extern c: Talking to C Programmers about C++”
https://www.youtube.com/watch?v=D7Sd8A6_fYU
Embedded Development with Dan Saks
http://cppcast.com/2016/10/dan-saks/
Regarding Java vs C++, yes the enterprise world has adopted Java, however as someone doing consulting across Java, .NET and C++, I am really seeing it coming back since ANSI C++ has picked up steam again.
I see it in projects related to IoT, AI, VR, big data,....
They are all polyglot projects with C++ plus something else, not C plus something else.
As noted, unless we are speaking about PICs with 8KB and similar, the majority of them can easily be targeted by C++, which is what Arduino and ARM mbed do.
Already in MS-DOS, on 640KB computers, using C made little sense.
When we needed performance, Assembly was the only option, because the code any compiler was generating in those days was average quality on their better days.
When performance wasn't that critical, then the improved type system, RAII, reference types, type safe encapsulations were already better than using plain C.
We even had frameworks like Turbo Vision available.
So if something like a PCW 512 didn't had issues with C++, so a modern micro-controller can also be targeted by it, except for political reasons.
Developers that are against anything other than C, even if their compiler nowadays happens to be written in C++ (e.g. gcc, clang, icc, vc).
Is assembly important in microcontrollers?
Actually writing assembly is more of a last resort time.
Reading assembly is more useful, especially if your platform's debugger isn't very good.