{
  "$type": "site.standard.document",
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  "path": "/t/change-error-message-of-a-failing-assert-eq/24118#post_16",
  "publishedAt": "2026-03-31T09:09:32.000Z",
  "site": "https://internals.rust-lang.org",
  "tags": [
    "[1]",
    "↩︎"
  ],
  "textContent": "I'd find it much more valuable if the output would highlight the actual difference. When asserting equality between structs (especially large or nested ones) you often get two blobs of `std::fmt::Debug` outputs you have to look through to find a (sometimes) one character difference.\n\nNot sure on the feasability of that though [1], but even diff on the output text + color highlighting would be very useful in that situation. Example (inspired by Wordle):\n\n  * Red for sections that don't occur in the Debug output of the other side\n  * Optional: Orange for (larger) sections that are in the other side but not in the same place\n  * White for matching sections (same place/order)\n\n\n\n* * *\n\n  1. Especially when order does not matter for equality like with HashMap. ↩︎\n\n\n",
  "title": "Change error message of a failing `assert_eq!`"
}