Macro std::dbg

macro dbg($value) { ... }

source

A helper for printing a value of a subexpression for debugging purposes.

It prints the value to standard error with code location (file, line, column) and returns the value.

Example

let a = 1;
// Prints "[<filename>:<line>:<column>] a + 1 = 2"
let b = 2 * dbg!(a + 1);

assert_eq!(b, 4);
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