From 11d2cf0d604dee3f5023c17802d69438e69fa50e Mon Sep 17 00:00:00 2001 From: Taylor Yu Date: Sat, 15 May 2021 14:01:17 -0500 Subject: [PATCH] fix(try_from_into, from_str): hints for dyn Error Add hints about how to return the correct type for functions that return `Result<_, Box`. Some feedback from Discord suggests that people run into trouble with that. --- info.toml | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/info.toml b/info.toml index 82e119522d..0535a77b7a 100644 --- a/info.toml +++ b/info.toml @@ -893,7 +893,19 @@ path = "exercises/conversions/try_from_into.rs" mode = "test" hint = """ Follow the steps provided right before the `TryFrom` implementation. -You can also use the example at https://doc.rust-lang.org/std/convert/trait.TryFrom.html""" +You can also use the example at https://doc.rust-lang.org/std/convert/trait.TryFrom.html + +You might want to look back at the exercise errorsn (or its hints) to remind +yourself about how `Box` works. + +If you're trying to return a string as an error, note that neither `str` +nor `String` implements `error::Error`. However, there is an implementation +of `From<&str>` for `Box`. This means you can use `.into()` or +the `?` operator to convert your string into the correct error type. + +If you're having trouble with using the `?` operator to convert an error string, +recall that `?` works to convert `Err(something)` into the appropriate error +type for returning from the function.""" [[exercises]] name = "as_ref_mut" @@ -909,4 +921,7 @@ mode = "test" hint = """ The implementation of FromStr should return an Ok with a Person object, or an Err with an error if the string is not valid. -This is almost like the `try_from_into` exercise.""" +This is almost like the `try_from_into` exercise. + +If you're having trouble with returning the correct error type, see the +hints for try_from_into."""