fmt_log

This module contains macros for logging to the console using the std::println! or std::eprintln! macros, but also returns the formatted string.

Disclaimer: this started as a fun experiment on how to create a custom macro like the std::println! one, and now I'm using it to print logs and get the formatted output at the same time.

fmt_printf example

use fmt_log::fmt_printf;

let s1 = "Hello";
let s2 = String::from("world!");
let n1 = 123;

let output = fmt_printf!("{}, {} {}", s1, s2, n1);

assert_eq!(output, format!("{}, {} {}", s1, s2, n1));

This will log "Hello, world! 123" to the console.

fmt_errorf example

use fmt_log::fmt_errorf;

let s1 = "Hello";
let s2 = String::from("world!");
let n1 = 123;

let output = fmt_errorf!("{}, {} {}", s1, s2, n1);

assert_eq!(output, format!("{}, {} {}", s1, s2, n1));

This will log "Hello, world! 123" to the stderr.