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by masklinn 3026 days ago
> But a string is a container

In the same way unique_ptr is a container.

> so string.deref() returns.... &str?

Yes? &str::deref() also returns &str, Vec::deref() returns &[], Box<T>::deref() returns &T.

That's literally how Deref is defined, Deref<Target=T>::deref() returns &T.

*String returns str.

> (FromStr vs From<&str>, .parse() vs .into())

These are not equivalent. From/Into are non-failing conversions, FromStr can fail.

What you're looking for is TryFrom/TryInto which are still not done 2 years into the RFC: https://github.com/sfackler/rfcs/blob/try-from/text/0000-try...

1 comments

> * String returns str.

Typed that out too fast, yes, that's my problem. * String is one thing but String.deref() is another. But * is the dereference operator. Operator overloading ftw ;)

> What you're looking for is TryFrom/TryInto which are still not done 2 years into the RFC: https://github.com/sfackler/rfcs/blob/try-from/text/0000-try....

Sorry, yes, I actually opened an issue with my suggestions regarding that one with particular focus on the fallible vs infallible nature: https://github.com/rust-lang/rfcs/issues/2143

> Typed that out too fast, yes, that's my problem. * String is one thing but String.deref() is another. But * is the dereference operator.

They're the same thing, Deref::deref() is just the operation which underlies the dereferencing operator.

Either way I don't see what's problematic about a string buffer deref'ing to a string.