@Allan and @Joseph, I should have said that this as an intellectual exercise I want to write C++ that makes the warning go away, not a #pragma or similar that suppresses the message.
Yes, I know that all casts are dangerous. A extern "OS" * is I believe always the address of an "old-fashioned" entry point. I use it for my assembler routines. I suspect it is safe to cast. In this case, it is an address filled in by LOAD, so it is certainly a module in memory, not a vftable. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Allan Kielstra Sent: Wednesday, January 29, 2020 12:27 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: C++ reinterpret_cast question Also, I trust that you know what you're doing! Depending on the implementation of C++, a pointer to a function can sometimes be a pointer to a function descriptor. So be careful with what you do with opts_char. (But you say that the resulting code basically works so that is good.) Also, on USS ahk> cat cm.C extern "OS" typedef int mytype(void *); extern mytype M; void p() { char *x; x = reinterpret_cast<char *>(M); } ahk> xlC -c cm.C "./cm.C", line 8.33: CCN5216 (W) An expression of type "extern "OS" int (*)(void *)" cannot be converted to type "char *". ahk> xlC -c -qsuppress=CCN5216 cm.C ahk> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
