Tweaking clang-format for C++20 ranges pipelines - c++

Question

C++20 (and 23 with std::ranges::to<T>()) makes idiomatic the use of operator| to make a pipeline of transformations such as this:
return numbers
| std::views::filter([](int n) { return n % 2 == 0; })
| std::views::transform([](int n) { return n * 2; })
| std::ranges::to<std::vector>();
With my project's current .clang-format, that looks something like
return numbers | std::views::filter([](int n) { return n % 2 == 0; }) |
std::views::transform([](int n) { return n * 2; }) | std::ranges::to<std::vector>();
which I find pretty hard to read. If I set BreakBeforeBinaryOperators: All I get
return numbers | std::views::filter([](int n) { return n % 2 == 0; })
| std::views::transform([](int n) { return n * 2; }) | std::ranges::to<std::vector>();
which is better, but I'd really like the original version with one pipeline operation on each line.
I can adjust the column limit, but that is a major change and also starts to line-break my lambdas, which I don't like:
return numbers | std::views::filter([](int n) {
return n % 2 == 0;
})
| std::views::transform(
[](int n) { return n * 2; })
| std::ranges::to<std::vector>();
I can manually use empty comments to force a newline:
return numbers //
| std::views::filter([](int n) { return n % 2 == 0; }) //
| std::views::transform([](int n) { return n * 2; }) //
| std::ranges::to<std::vector>();
but again, not ideal knowing that pipelines will be pretty common. Am I missing settings? Or is this more of a feature request I should direct to clang-format, like "Add an option so when more than n operator| appears in an expression, put each subexpression on its own line."

Answer 1

There's a feature request for AllowBreakingBinaryOperators. Before the feature completes, only compromise can be made.
As you've said, use // comments to force line breaks.
use clang-format off/on to disable clang-format and format it yourself.
Here's a more complex solution which combines both:
void function() {
return numbers | std::views::filter([](int n) { return n % 2 == 0; })
| std::views::transform([](int n) { return n * 2; })
| std::views::take(3) | std::ranges::to<std::vector>();
}
First, use // to split and then clang-format the code.
void function() {
return numbers
//
| std::views::filter([](int n) { return n % 2 == 0; })
| std::views::transform([](int n) { return n * 2; })
| std::views::take(3)
//
| std::ranges::to<std::vector>();
}
Next, remove //, use clang-format off/on to disable clang-format.
void function() {
// clang-format off
return numbers
| std::views::filter([](int n) { return n % 2 == 0; })
| std::views::transform([](int n) { return n * 2; })
| std::views::take(3)
| std::ranges::to<std::vector>();
// clang-format on
}
As for matrix, the option AlignArrayOfStructures might help.