Appends the structures contained in @caps2 to @caps1 if they are not yet
expressed by @caps1. The structures in @caps2 are not copied -- they are
transferred to a writable copy of @caps1, and then @caps2 is freed.
If either caps is ANY, the resulting caps will be ANY.
Appends the structures contained in @caps2 to @caps1 if they are not yet expressed by @caps1. The structures in @caps2 are not copied -- they are transferred to a writable copy of @caps1, and then @caps2 is freed. If either caps is ANY, the resulting caps will be ANY.