A [no_std] library for lazily formatting things. Because allocating temporary strings just to write them to a buffered stream is bad for your health.
use std::io;
use lazy_format::lazy_format;
use joinery::JoinableIterator;
fn main() {
let result = (0..10)
.map(|value| lazy_format!("\t'{}'", value))
.join_with("\n")
.to_string();
assert_eq!(result,
" '0'
'1'
'2'
'3'
'4'
'5'
'6'
'7'
'8'
'9'")
}The above example is the key motivating example: when building up some kind of object you wish to write or format, there's no reason to allocate intermediary strings (which is what format! does). Instead, lazy_format! captures its arguments and returns an opaque struct with a Display implementation, so that the actual formatting can happen directly into its final destination buffer (such as a file or string).