Dual Api

Something which has long annoyed the purists in the C++ leadership is the problem of dual overloads in error_code capable standard library APIs. Consider the copy_file() API from the Filesystem TS: namespace filesystem { /*! Copies the file at path `from` to path `to`. \returns True if file was successfully copied. \throws On failure throws `filesystem_error(ec.message(), from, to, ec)` with `ec` being the error code reported by the operating system. */ bool copy_file(const path &from, const path &to); /*! »