cpp/io/basic ios/copyfmt

If refers to the same object as, has no effects. Otherwise, copies the state of the stream into. This is done in the following sequence:

@1@ Calls every callback registered by register_callback passing as parameter.

@2@ Copies all member objects from to  except for rdstate, the exception mask, and rdbuf. In particular, makes copies of the locale, the formatting flags, the contents of the arrays std and std (but not the and  pointers themselves), the callbacks, and the tied stream.

@3@ Calls every callback registered by register_callback passing as parameter.

@4@ Copies the exception mask from to  as if by calling.