wp-includes/option.php:1774Adds or updates user interface setting.
$namestring$valuestringbool|nullfunction set_user_setting( $name, $value ) { if ( headers_sent() ) { return false; } $all_user_settings = get_all_user_settings(); $all_user_settings[ $name ] = $value; return wp_set_all_user_settings( $all_user_settings );}Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/option.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.