[scoutt]

> the terribleness of exceptions is way overhyped

It's not that exceptions are terrible. I have nothing against them. The thing is that most of the time they are not affordable, especially in embedded. Some compilers don't even support them (some 8-bit IIRC). Most (including mine) embedded C++ programs have exceptions disabled.

> return a `std::optional`

The same goes for std. I don't know the overhead of possibly duplicating these classes(1) for every instance of std::optional. Most (including mine) embedded C++ programs don't use std.

30KB of extra code is nothing for desktop/server applications, but it's not convenient for a MCU with 64KB of flash.

(1): https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-...

> just use a factory function instead

This is practical with an efficient heap allocator (which I might not have). What happens if I want a scoped (on stack) instance of a class?

See how things are quickly getting more complicated with C++?

[OskarS]

It's that amount of lines UNCOMPILED. Of course uncompiled code wouldn't fit in 64kb of flash (the compiler wouldn't fit either, you know). Compiled, std::optional takes up essentially no overhead, basically the same as if you're returning a single bool along with your object.

> This is practical with an efficient heap allocator (which I might not have). What happens if I want a scoped (on stack) instance of a class?

There is absolutely no reason to do a heap allocation for a factory function in modern C++ (or even relatively ancient C++, in fact). The fact that you would think so indicates you simply don't know C++ at all.

Tell me, where in these six lines do you see a heap allocation? Where in the total of 6 instructions this compiles down to do you see anything that couldn't run in any embedded environment? Tell me how these six instructions wouldn't fit inside your 64kb of flash:

https://godbolt.org/z/rErWPbbbx

And again, EVEN IF you're so religiously and irrationally opposed to using std::optional, you can just return a default-constructed object and an extra bool indicating successful construction. I don't know why you would considering you could just return an optional, but whatever, you can do it that way if that's what you prefer.

You're just wrong about this stuff, and it's this kind of lazy, uniformed criticism of C++ that really rubs me the wrong way. If you wanna use C, use C! Nobody's stopping you, it's a fine language. Just leave the C++ discussions to the people who actually know what the language is.

[scoutt]

Just chill, OskarS. I know the difference between compiled code and source code. Regarding std::optional, I even admitted "I don't know the overhead of possibly duplicating...".

30KB was a ballpark about exceptions plus std in general, by including things you expect to use when using std (like std::string).

The patterns I knew and saw with std::optional usually returned "new something", but yeah, you can return a copy too if the class fits in the stack.

And I am not religiously and irrationally opposed to anything.

> really rubs me the wrong way

Relax, my friend. Life is short.

[OskarS]

> The patterns I knew and saw with std::optional usually returned "new something", but yeah, you can return a copy too if the class fits in the stack.

Oh, fer crying out loud... It DOES NOT return a copy, it constructs it directly in place. This is called "copy elision" (also known as "return value optimization", or RVO), and has been done by compilers for three decades, and is actually mandated behaviour in modern C++. I don't know where you saw these examples, but you would never use operator new with std::optional: it takes a value, not a pointer.

You have a very annoying style of being wrong about absolutely everything you say, and then acting superior about it when people call you on your bullshit.