Concatenates literals into a static string slice.
This macro takes any number of comma-separated literals, yielding an expression of type &'static str
which represents all of the literals concatenated left-to-right.
Integer and floating point literals are stringified in order to be concatenated.
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/macro.concat.html