---
title: "isTriviallyIdentical(to:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/substring/istriviallyidentical(to:)"
---

# isTriviallyIdentical(to:)

Returns a boolean value indicating whether this substring is identical to other.

## Declaration

```swift
func isTriviallyIdentical(to other: Substring) -> Bool
```

## Discussion

Discussion Two substring values are identical if there is no way to distinguish between them. For any values a, b, and c: a.isTriviallyIdentical(to: a) is always true. (Reflexivity) a.isTriviallyIdentical(to: b) implies b.isTriviallyIdentical(to: a). (Symmetry) If a.isTriviallyIdentical(to: b) and b.isTriviallyIdentical(to: c) are both true, then a.isTriviallyIdentical(to: c) is also true. (Transitivity) a.isTriviallyIdentical(b) implies a == b. a == b does not imply a.isTriviallyIdentical(b) Values produced by copying the same value, with no intervening mutations, will compare identical: let d = c print(c.isTriviallyIdentical(to: d)) // Prints true Comparing substrings this way includes comparing (normally) hidden implementation details such as the memory location of any underlying substring storage object. Therefore, identical substrings are guaranteed to compare equal with ==, but not all equal substrings are considered identical. note: O(1)