Converting &[&char] to String

[KeironO]

Hey there,

I'm attempting to use Rust for some text processing, but am struggling to fully comprehend how I'd deal with the following.

I'm using the following:

sequence.chars().collect::,Vec<char>>().iter().collect::<Vec<_>>().windows(2);

To get all combinations of two characters, however I'm struggling to join the characters using the to_string() method.

  --> src/lib.rs:20:36
   |
20 |             println!("{:?}", slice.to_string());
   |                                    ^^^^^^^^^
   |
   = note: the method `to_string` exists but the following trait bounds were not satisfied:
           `&[&char] : std::string::ToString`
           `[&char] : std::string::ToString`

I don't even know what the type &[&char] means - given the fact that there is certainly 2 characters in the given window, so I'm struggling to get my head around it.

Best wishes,

Keiron

[asymmetrikon]

&[&char] is a slice of char references - Rust can't know that there are 2 at compile time, since the variable passed to windows could potentially be decided at runtime (this should be able to be changed with const generics.) You can collect it into a string by doing slice.iter().copied().collect::<String>().

[KeironO]

Thank you so much for the help!

I'm astonished at the performance improvements Rust is giving me.