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The C++ standard for the F-35 Fighter Jet [video]

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327 points AareyBaba | 1 comments | 07 Dec 25 18:07 UTC | HN request time: 0.2s | source
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time4tea ◴[07 Dec 25 19:31 UTC] No.46184345[source]▶
a = a; // misra

Actual code i have seen with my own eyes. (Not in F-35 code)

Its a way to avoid removing an unused parameter from a method. Unused parameters are disallowed, but this is fine?

I am sceptical that these coding standards make for good code!

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unwind ◴[07 Dec 25 19:43 UTC] No.46184460[source]▶
For C, the proper/expected/standard way to reference a variable without accessing it is a cast to void:

    (void) a;
I'm sure there are commonly-implemented compiler extensions, but this is the normal/native way and should always work.
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amluto ◴[07 Dec 25 22:12 UTC] No.46185753[source]▶
Not if you use GCC.

https://godbolt.org/z/zYdc9ej88

clang gets this right.

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1. account42 ◴[09 Dec 25 10:25 UTC] No.46203376[source]▶
a) __attribute__((warn_unused_result)) is non-standard in the first place, are you looking for [[nodiscard]] - GCC does not warn on cast to void with that?

b) A return value that is explicitly marked like this is very different from an unused variable that gp suggested the cast to void idiom for. GCC does not warn on variables that are unused except for a cast to void.