saw this in Strings.kt for `String.trim()` and im ...

# announcements

[Tim]

saw this in Strings.kt for String.trim() and im just curious, why the cast to CharSequence?

/**
 * Returns a string having leading and trailing whitespace removed.
 */
@kotlin.internal.InlineOnly
public inline fun String.trim(): String = (this as CharSequence).trim().toString()

[Kroppeb]

Otherwise it would be recursive. this.trim() would call String.trim() instead of CharSequence.trim()

[Tim]

oh right 🙂 neat, thanks!

[streetsofboston]

Also, when you see an 'odd' thing like this (seemingly unnecessary up-cast), extension functions are statically bound

[Mark]

I guess this is an important consideration when deciding whether to declare an extension function vs. instance function.