wp-includes/pomo/streams.php:105$input_stringstringint public function strlen( $input_string ) { if ( $this->is_overloaded ) { return mb_strlen( $input_string, 'ascii' ); } else { return strlen( $input_string ); } }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/pomo/streams.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.