Proposed resolution:

This wording is relative to N4582.

1. Modify [fs.op.copy_file] as indicated:

   bool copy_file(const path& from, const path& to, copy_options options);
   bool copy_file(const path& from, const path& to, copy_options options,
                  error_code& ec) noexcept;
   

   -3- Requires: At most one constant from each copy_options option group (27.10.10.2) is present in options.

   -4- Effects: Report a file already exists error as specified in Error reporting (27.5.6.5) if:

   • !is_regular_file(from), or
   • exists(to) and !is_regular_file(to), or
   • exists(to) and equivalent(from, to), or
   • exists(to) and (options & (copy_options::skip_existing | copy_options::overwrite_existing | copy_options::update_existing)) == copy_options::none.

[ 2016-08 Chicago ]

Wed AM: Move to Tentatively Ready

[ 2016-05-28, Eric Fiselier provides wording ]

[ 2016-05 Issues Telecon ]

Eric to provide wording.

There are a number of error cases that copy_file(from, to, ...) does not take into account. Specifically the cases where:

1. from does not exist
2. from is not a regular file
3. to exists and is not a regular file

These error cases should be specified as such.