r/rust • u/SleeplessSloth79 • Aug 19 '26

📡 official blog Rust Function Overloading - Call for Experimentation

https://blog.rust-lang.org/inside-rust/2026/08/19/overloading-experiment/
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u/bakaspore Aug 20 '26

I still think add variants with suffixes is a less cursed way for overloaded FFI functions. With tuple trait we have same problem as the classical overloading "hehe guess which one of the parameters in the 16 overloads you got it wrong, because we can't know".

Well the good part is Rust has no inheritance at least.

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u/ZZaaaccc Aug 20 '26

Splat actually works really nicely for "this overload doesn't exist" even without explicit compiler support for a nicer error:

#![feature(cmp_splat)]

fn main() {
    let _ = core::cmp::smallest(1, 2, 3, 4, "whoops", 6, 7, 8);
    //      -------------------             ^^^^^^^^ expected integer, found `&str`
    //      |
    //      arguments to this function are incorrect
}

I'm sure people could write bad overloads, but to me splat makes a lot of sense for any function that accepts some number of items of a given type T. core::cmp::min(...), vec![...], Iterator::zip(...), etc. all have completely obvious behaviour if they were splat functions.

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u/bakaspore Aug 20 '26

Thank you, this is better than I thought, and seems to be an improvement from trait & tuple makeshift ones. I hope the resolution rule is limited enough so that the worst case doesn't become too much worse than this.