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Re: Order of addresses of string-literals inside a translation unit

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James Kuyper <jameskuyper@alumni.caltech.edu> writes:

> Note, in particular, that because writing to the memory allocated to
> store the string corresponding to a string literal has undefined
> behavior, it's entirely permissible for an implementation to make all
> occurrences of "Hello, world!" in a given program point at the same
> location in memory, and to make "Hello, world!" + 7 == "world!".  Both
> optimizations have actually been implemented by many implementations.

It's true that two or more string literals may have some bytes in
common, but that's not because writing to a byte in a string
literal has undefined behavior;  it's because there is an explicit
statement in the C++ standard (and also the C standard) that allows
it.  If anything the implication goes the other direction:  because
pre-standard C implementations stored multiple string literals in
the same memory, when C was standardized it was pretty much a
necessity that storing into the bytes of a string literal had to
be undefined behavior.

Nitpick:  a string literal need not be a string (as the C standard
points out, in a footnote IIRC).

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Order of addresses of string-literals inside a translation unit Bonita Montero <Bonita.Montero@gmail.com> - 2023-02-22 14:31 +0100
  Re: Order of addresses of string-literals inside a translation unit Richard Damon <Richard@Damon-Family.org> - 2023-02-22 20:34 -0500
    Re: Order of addresses of string-literals inside a translation unit James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-02-23 00:00 -0500
      Re: Order of addresses of string-literals inside a translation unit Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-23 13:52 -0800
        Re: Order of addresses of string-literals inside a translation unit Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-24 09:03 -0800
      Re: Order of addresses of string-literals inside a translation unit Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-24 08:55 -0800
        Re: Order of addresses of string-literals inside a translation unit "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2023-02-24 09:43 -0800
          Re: Order of addresses of string-literals inside a translation unit Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-03-14 08:48 -0700
  Re: Order of addresses of string-literals inside a translation unit Öö Tiib <ootiib@hot.ee> - 2023-02-22 23:59 -0800
    Re: Order of addresses of string-literals inside a translation unit scott@slp53.sl.home (Scott Lurndal) - 2023-02-23 16:18 +0000

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