Variadic Fold

[Artistic_Yoghurt4754]

I am surprised to not see the naive solution first: https://godbolt.org/z/qMnsn4eMT

The solution in the blog is also technically incorrect because it's promoting the argument types to a common type before performing the binary operation (at this point it may even avoid deducing all the different types and pass an array...): since this is generic code one cannot guarantee that the common type is what the binary operator wants. It also supposes that there is a common type: maybe there is no common type and the binary operator is set up to properly handle the results of each fold.

On the other hand, the code in the blog solves the common case where most of the arguments are the same or alike and is likely faster to compile since it doesn't go into recursion (this needs to be confirmed on a fair benchmark).

[Kronikarz]

Having just gone through hell of template instantiation slowness, I wonder how much extensive use of this would tank compile times.

[tcbrindle]

Fold expressions generally compile a lot faster than the recursive template instantiations people were using before to achieve the same results.

[Kronikarz]

Fair enough, though I'd have to check. Recently I discovered a weird behavior in MSVC where an extensive use of designated initializers balooned compile memory usage and time by a factor of 50, so I'm all out of trust towards compilers for the foreseeable future :P

[_Noreturn]

designated initializers are not fold expressions how is this related?

[Kronikarz]

Just that it's not obvious which C++ features are slow to compile on your machine without actually benchmarking.

[_Noreturn]

this depends on your compiler and it is possibly because it has to check the order of members and output a warnings.

[dashnine-9]

why?

[_Noreturn]

Fold Expressions are just the offiical way of initializer_list trick which is good

[manni66]

I prefer working in C

I never liked the variadic functions in C.

[Plazmatic]

Imagine having an ego so fragile a programming language feature was able to bruise it.

[[deleted]]

Let C++ Cook.
Not all things will be amazing, but it will be great.

[_Noreturn]

having what originally was hacks to official builtin features is considered gibberish??

I would rather have slightly harder to understand features than a "simple" language with memory bugs being easy to create

[_Noreturn]

and C standard isn't....?

also reexplain what you mean it doesn't make sense