> I wonder if OP's C++ port doesn't use iterators that much, and how idiomatic it is.

I think I only used iterators in places where there's no built-in function on slices like C++'s strchr and strspn. (I think Rust's str has these, but not [u8].) For example:

C++: https://github.com/quick-lint/cpp-vs-rust/blob/f8d31341f5cac...

    std::size_t length = std::strcspn(c, separators);
    if (c[length] == '\0') {
      return found_separator{.length = length,
                             .which_separator = static_cast<std::size_t>(-1)};
    }
    const char* separator = std::strchr(separators, c[length]);

Rust: https://github.com/quick-lint/cpp-vs-rust/blob/f8d31341f5cac...

    match s
        .as_bytes()
        .iter()
        .position(|c: &u8| separators.contains(c))
    {
        None => FoundSeparator {
            length: s.len(),
            which_separator: INVALID_WHICH_SEPARATOR,
        },
        Some(length) => {
            let found_separator: u8 = unsafe { *s.as_bytes().get_unchecked(length) };
            match separators.iter().position(|c: &u8| *c == found_separator) {

Of course it exists in C++, and has done since before Rust even existed.

Syntax is usually `vector | map | collect`.

> Of course it exists in C++, and has done since before Rust even existed.

Not in C++'s standard library until C++20.

Things don't need to be standardized in an ISO document to exist and be readily available.

I remember using it as early as 2008.

Wow, my C++ knowledge is even worse than I thought. I didn't know it had "pipelines".

https://en.cppreference.com/w/cpp/ranges

It's not "pipelines". It's just an overloaded bitwise-or operator.

> It usually does that on iterator chains, which AFAIK do not exist as such in C++, so multiple operations would be expressed as multiple imperative statements.

https://en.cppreference.com/w/cpp/ranges

Before C++20, similar functionality has been available in boost.