Macro custom_print::dbgwrite

macro_rules! dbgwrite {
    ( $macro:path, $writer:expr, expect, $format:literal $(, $($args:tt)+)? ) => { ... };
    ( $macro:path, $writer:expr, try, $format:literal $(, $($args:tt)+)? ) => { ... };
}

Prints and returns the value of a given expression for quick and dirty debugging with the specified write macro, writer, format and error-handling policy.

The implementation of the dbgwrite macro is based on std::dbg macro implementation, but the exact output printed by std::dbg should not be relied upon and is subject to future changes.

If the try policy is used, it propagates write error and returns values wrapper into Result.

Panics

The macro panics if writing fails and the expect policy is used.

Examples

use core::fmt::Write;
let mut string = String::new();

assert_eq!(custom_print::dbgwrite!(writeln, &mut string, expect, ":?", "first"), ("first"));
assert!(string.contains("\"first\""));
assert_eq!(custom_print::dbgwrite!(writeln, &mut string, try, ":?", "second"), Ok(("second")));
assert!(string.contains("\"second\""));