verbose errors feature #551
Conversation
This adds a new "verbose-errors" feature flag to async-std that enables
wrapping certain errors in structures with more context. As an example,
we use it in `fs::File::{open,create}` to add the given path to the
error message (something that is lacking in std to annoyance of many).
|
We discussed this a while back, and I wanted to provide something small that can be a basis for discussion. The main thing here is to provide an internal mechanism to easily add optional contexts. I hope–but have not proven–that the closure get compiled away in release modes without the feature flag set. |
|
This is great, thank you! :) I think we don't even need to introduce a new feature flag for this and can just provide verbose errors by default. Is there any real downside to providing this by default? Wdyt, @yoshuawuyts ? |
|
It costs a string allocation in the error case 🤷 |
|
Error cases don't need to be fast :) Besides, we already have a string allocation for the |
killercup
force-pushed
the
feature/verbose-errors
branch
from
a9f134d
to
35356a7
Compare
| use std::{error::Error as StdError, fmt, io}; | ||
|
|
||
| #[derive(Debug)] | ||
| pub(crate) struct VerboseError { |
There was a problem hiding this comment.
I'm sure this type could be using source: T but let's refactor this when we have a use case
killercup
force-pushed
the
feature/verbose-errors
branch
from
35356a7
to
c704643
Compare
This adds a new "verbose-errors" feature flag to async-std that enables
wrapping certain errors in structures with more context. As an example,
we use it in
fs::File::{open,create}to add the given path to theerror message (something that is lacking in std to annoyance of many).