macro_rules! format_args {
($fmt:expr, $($args:tt)*) => { ... };
} The core macro for formatted string creation & output.
This macro produces a value of type fmt::Arguments. This value can be passed to the functions in std::fmt for performing useful functions. All other formatting macros (format!, write!, println!, etc) are proxied through this one.
For more information, see the documentation in std::fmt.
use std::fmt;
let s = fmt::format(format_args!("hello {}", "world"));
assert_eq!(s, format!("hello {}", "world"));
© 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.format_args.html