Macro dbg

dbg!() { /* proc-macro */ }

Emit a temporary event as a quick-and-dirty debugging aid.

Examples

let x = 42;
let y = true;

emit::dbg!(x, y);

Syntax

(property),*
template_literal, (property),*

where

• template_literal: A template string literal.
• property: A Rust field-value for a property to capture.

Template literals

Templates are text literals that include regular text with holes. A hole is a point in the template where a property should be interpolated in.

See the guide for more details and examples of templates.

Properties

Properties that appear within the template or after it are added to the emitted event. The identifier of the property is its key. Property capturing can be adjusted through the as_* attribute macros.

Unlike debug, this macro captures values using their Debug implementation by default.

See the guide for more details on property capturing.

When to use dbg

This macro is a convenient way to pepper debug logs through code, but follows the same recommendations as the standard library’s dbg macro. You shouldn’t expect dbg statements to be long lived, and use the debug macro instead with more deliberate data.

See the guide for more details.