Hacker News new | ask | show | jobs
by codedokode 1477 days ago
You are right. First version of code actually used std::shared_ptr<Data>(new Data) (and produced similar code), but then I thought that it is unfair that we create a struct on a stack in Rust, so I changed the code. I should have used gcc with -Wall that detects the problem (clang doesn't).
3 comments

Then, instantiate the smart pointer with a custom no-op deleter and if you use the nt typedef I mentioned above, you'll get a similar compiler output to Rust's.

e.g nt_shared_ptr<Data> x(&d, [](Data*) -> void{});

https://godbolt.org/z/d3qv4cE1v

It is a rookie mistake to wrap the result of new into a shared_ptr. It makes two heap allocations. You should use std::make_shared. It combines both and makes only one allocation.
Why call new? I work on a several hundred k code base that has a single call to new.