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The C23 edition of Modern C

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515 points bwidlar | 2 comments | 15 Oct 24 16:06 UTC | HN request time: 0.55s | source
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belter ◴[15 Oct 24 17:30 UTC] No.41850897[source]▶
Important reminder just in the Preface :-)

Takeaway #1: "C and C++ are different: don’t mix them, and don’t mix them up"

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pjmlp ◴[15 Oct 24 17:35 UTC] No.41850960[source]▶
Specially relevant to all those folks that insist on "Coding C with a C++ compiler", instead of safer language constructs, and standard library alternatives provided by C++ during the last decades.
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com2kid ◴[15 Oct 24 17:48 UTC] No.41851082[source]▶
Perfectly valid to do if you need to interface with a large C code base and you just want to do some simple OO here and there. Especially if you cannot have runtime exceptions and the like.

This is how I managed to sneak C++ into an embedded C codebase. We even created some templates for data structures that supported static allocation at compile time.

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f1shy ◴[15 Oct 24 17:53 UTC] No.41851140[source]▶
What would be an example of "simple OO here and there" that cannot be done cleanly in plain C?
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adamrezich ◴[15 Oct 24 18:02 UTC] No.41851244[source]▶
Namespaces, methods.
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f1shy ◴[15 Oct 24 18:04 UTC] No.41851261[source]▶
Namespaces is not object orientation, is it? Am I missing something? You can place functions (methods) inside of structs in C23, can't you?
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int_19h ◴[15 Oct 24 18:20 UTC] No.41851481[source]▶
You can handcode vtables in C, just as you can handcode loops in assembly (i.e. it works but it's verbose, not particularly readable, and brings more footguns).

But why would you do that if you have an instrument that lets you work at the same level as C, but with methods provided as a proper abstraction that maps exactly to what you'd have written yourself anyway?

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1. uecker ◴[15 Oct 24 19:37 UTC] No.41852301[source]▶
I don't know, I never found the "proper abstraction" be more than irrelevant syntactic sugar. And the cost of C++ is that you end up putting everything in the header (IMHO the biggest design flaw of the language) and then compile time start to get long....
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2. int_19h ◴[18 Oct 24 15:26 UTC] No.41880301[source]▶
At the very least, the proper abstraction is the one that guarantees that you pass the same pointer as the first argument of the method call as the one you used to read the vtable from.

And no, you don't have to put everything in the header with C++, and especially not if you're using it in "C with classes" mode. C++ only needs it for templates - and even then only if you want to use implicit instantiation, with `extern template` available for fine-grained control allowing you to have those specializations separately compiled and implementations kept out of the header file.