std::String is a struct, and str is a type defined by the language. There's a summary of the differences at [0]. [0]: http://www.ameyalokare.com/rust/2017/10/

std::String is a struct, and str is a type defined by the language. There's a summary of the differences at [0]. [0]: http://www.ameyalokare.com/rust/2017/10/12/rust-str-vs-String.html http://www.ameyalokare.com/rust/2017/10/12/rust-str-vs-Strin...