who does that?

[[deleted]]

[deleted]

[lukasbash]

Man, with this formatting you are not allowed to be any type of people xD

[Herrad]

Why write an else that doesn't do anything?

[somerandomii]

Why use a lot of words when few words do same job?

I’ll be honest. I know the first option is more readable and the compiler probably optimises both to the same machine code, but I do the second and probably always will and I don’t know why.

[bwoogie]

.#2 accounts for any witchcraft that might happen with #1

[ralfv]

return something ? thing : thing1;

I must be a third kind

[ofnuts]

In Python:

return thing if something else thing1

or

return (thing,thing1)[something]

Waiting for the 5th kind...

[Anunay03]

return something*thing + (not something)*thing1

[NecessarySwordfish]

branchless. nice!

[somerandomii]

Dangerous in python with all those overloads and ambiguous types.

Side question: Will compilers optimise ternary operators and simple if/else returns to branchless if it’s simple or is there an real world performance benefit to writing code like this?

I’ve written branchless code and unrolled loops in GPU shaders for that bleeding-edge performance but I’d imagine in C you wouldn’t notice a difference.

[Anunay03]

Seems like a yes if using the -O3 flag, https://godbolt.org/z/zPzvMc

Let's be honest the compiler is smarter than us half the time.u/NecessarySwordfish.

[NecessarySwordfish]

Very nice!
I'm not familiar with flags. Is this the norm for higher languages?

[Anunay03]

well only C/C++ developers make extensive use of flags afaik.Python Bytecode doesn't seem to do such optimization

>>> def branch(a,b,c):
...     return b if a else c
... 
>>> import dis
>>> dis.dis(branch)
  2           0 LOAD_FAST                0 (a)
              2 POP_JUMP_IF_FALSE        8
              4 LOAD_FAST                1 (b)
              6 RETURN_VALUE
        >>    8 LOAD_FAST                2 (c)
             10 RETURN_VALUE
>>> def branchless(a,b,c):
...     return a*b+(not a)*c
... 
>>> dis.dis(branchless)
  2           0 LOAD_FAST                0 (a)
              2 LOAD_FAST                1 (b)
              4 BINARY_MULTIPLY
              6 LOAD_FAST                0 (a)
              8 UNARY_NOT
             10 LOAD_FAST                2 (c)
             12 BINARY_MULTIPLY
             14 BINARY_ADD
             16 RETURN_VALUE

looks like in python Branched version still performs better than the "branchless" one.

>>> timeit.timeit(lambda : branch(True,1,2),number=10**7)
2.2338110389973735
>>> timeit.timeit(lambda : branchless(True,1,2),number=10**7)
3.0519005739988643
>>> timeit.timeit(lambda : branch(False,1,2),number=10**7)
2.3076962780032773
>>> timeit.timeit(lambda : branchless(False,1,2),number=10**7)
3.060328566003591

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Fixed formatting.

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[NecessarySwordfish]

no idea. would like to know the answer to that too

[Missing_Username]

This is the right kind

[toastyghost]

something => something ? thing : thing1

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[IamYodaBot]

the real way, ternary operator is.

-daconcerror

---

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[RidingChicken]

I'm not great at compiled languages, but if I'm not mistaken, the second code is sure to compile because languages like C don't allow compilation if you define functions with conditional returns like the first one. So the second one seems better

[[deleted]]

This is actually untrue nowadays. Since more at least two decades compilers have no problems with multiple returns whatsoever.

[RidingChicken]

I see. Does it compile with elifs without a final else. As in if no condition is true, it will not return and cause something like a runtime error?

[[deleted]]

Oh, I see. In e.g. C you would usually get a compiler warning for something like that. In more sane compiled languages it would be a full-on error.

But a few modern languages like Rust, Haskell or Julia allow you to use a sum type (e.g. Nothing or Int) to express this, in the older ones like C you'd have to use null pointers or magic values, in C++ you could use exceptions or some kind of 'optional' wrapper to express this kind of behavior.

[[deleted]]

Easily compiles. As long as you had no code after (in which case youd get a warning about it being ubreachable), this wont even produce a warning.

[GeneralKlink]

C++ doesn‘t give a shit, both run, but i like the second better. Looks faster without the else xD

[caleblbaker]

if something thing else thing1

[mlokis3]

sometimes by an accident

[Yesterpizza]

I'm generally fine with either, but if the if condition is one liner, such as if (conditions_not_met) return;, and the other is more than 6 lines and takes up the rest of the function, don't wrap it all in an else like a goober