wp-includes/class-wp-rewrite.php:642Retrieves an extra permalink structure by name.
$namestringstring|false public function get_extra_permastruct( $name ) { if ( empty( $this->permalink_structure ) ) { return false; } if ( isset( $this->extra_permastructs[ $name ] ) ) { return $this->extra_permastructs[ $name ]['struct']; } return false; }Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-rewrite.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.