Macro custom_print::define_try_dbg

macro_rules! define_try_dbg {
    ( $( #[$meta:meta] )* $name:ident, $($args:tt)* ) => { ... };
}

Defines try_dbg macro that prints and returns the value of a given expression wrapped in for quick and dirty debugging or return an error if write failed.

The implementation of the generated dbg-like 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.

The first argument specifies the generated macro name. The writer itself is specified by the rest arguments with the define_writer macros.

Use define_dbg if you need to define a non-fallible dbg macros.

Examples

let mut string = String::new();
custom_print::define_try_dbg!(try_dbg, concat, |value: &str| string += value);

assert_eq!(try_dbg!("value"), Ok("value"));
assert!(string.contains("\"value\""));