perlop Document clarification

# New Ticket Created by  Linda Walsh 
# Please include the string:  [perl #46581]
# in the subject line of all future correspondence about
this issue. 
# <URL: h
ttp://rt.perl.org/rt3/Ticket/Display.html?id=46581 >



This is a bug report for perl from perl-diddlertlinx.org,
generated with the help of perlbug 1.35 running under perl
v5.8.8.


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[Please enter your report here]
On "perlop" manpage, under "Assignment
Operators", it says:

"Assignment operators work as in C.  That is,

    $a += 2;

is equivalent to

    $a = $a + 2;

although without duplicating any side effects that
dereferencing the
lvalue might trigger, such as from tie().  ..."
-----
It might be more clear if the "although"
continued:

"although without generating warnings or duplicating
side effects that
dereferencing the lvalue might trigger, such as modifying an
lvalue that
starts with an undefined value or side effects caused by
tie()."

The bit about "no warnings" when the lvalue starts
with "undef" seems
important enough to mention.  Eliminating warnings isn't the
first
thing I think of as a "side effect" of
dereferencing an lvalue.

Linda W.


[Please do not change anything below this line]
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---
Flags:
    category=docs
    severity=low
---
Site configuration information for perl v5.8.8:

Configured by rurban at Sun Jul  8 19:08:44 GMT 2007.

Summary of my perl5 (revision 5 version 8 subversion 8)
configuration:
  Platform:
    osname=cygwin, osvers=1.5.24(0.15642),
archname=cygwin-thread-multi-64int
    uname='cygwin_nt-5.1 reini 1.5.24(0.15642) 2007-01-31
10:57 i686 cygwin '
    config_args='-de -Dmksymlinks -Duse64bitint -Dusethreads
-Uusemymalloc -Doptimize=-O3 -Dman3ext=3pm
-Dusesitecustomize -Dusedevel'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef
useithreads=define usemultiplicity=define
    useperlio=define d_sfio=undef uselargefiles=define
usesocks=undef
    use64bitint=define use64bitall=undef
uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags ='-DPERL_USE_SAFE_PUTENV
-fno-strict-aliasing -pipe -Wdeclaration-after-statement',
    optimize='-O3',
    cppflags='-DPERL_USE_SAFE_PUTENV -fno-strict-aliasing
-pipe -Wdeclaration-after-statement'
    ccversion='', gccversion='3.4.4 (cygming special, gdc
0.12, using dmd 0.125)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8,
byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define,
longdblsize=12
    ivtype='long long', ivsize=8, nvtype='double', nvsize=8,
Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='ld2', ldflags =' -s -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib /lib
    libs=-lgdbm -ldb -ldl -lcrypt -lgdbm_compat
    perllibs=-ldl -lcrypt -lgdbm_compat
    libc=/usr/lib/libc.a, so=dll, useshrplib=true,
libperl=libperl.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef,
ccdlflags=' -s'
    cccdlflags=' ', lddlflags=' -s -L/usr/local/lib'

Locally applied patches:
    CYG01 - hints.cygwin.sh ldflags -s
    CYG02 - lib-ExtUtils-Embed insensitive against leading
\s
    CYG03 - lib-Test-Harness-Straps $ENV = ''
    CYG04 - major.version.cygwin.sh cygperl-5_8.dll and not
cygperl-5_8_x.dll
    CYG05 - add Win32CORE to core
    CYG07 - File-Spec-Cygwin-TMPDIR.patch
    Bug#38628 - allow legacy Cwd->cwd()
    Bug#40103 - File-Spec-case_tolerant.patch from 5.9.5

---
INC
for perl v5.8.8:
    /usr/lib/perl5/5.8/cygwin
    /usr/lib/perl5/5.8
    /usr/lib/perl5/site_perl/5.8/cygwin
    /usr/lib/perl5/site_perl/5.8
    /usr/lib/perl5/site_perl/5.8
    /usr/lib/perl5/vendor_perl/5.8/cygwin
    /usr/lib/perl5/vendor_perl/5.8
    /usr/lib/perl5/vendor_perl/5.8
    .

---
Environment for perl v5.8.8:
    CYGWIN=notitle glob:ignorecase export
    HOME=/home/law
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
   
PATH=.:/sbin:/usr/sbin:/home/law/scripts:/home/law/bin:/usr/
local/bin:/usr/bin:/bin:/usr/X11R6/bin:/usr/bin:/usr/lib:/WI
NDOWS/system32:/WINDOWS:/WINDOWS/System32/Wbem:/Prog/XP-Supp
ort Tools:/Prog/sysinternals:/Prog/Codeplay:/Prog/Common
Files/GTK/2.0/bin:/Prog/Microsoft Visual
Studio/Tools:/usr/lib/lapack:/c/Prog/Sysinternals/cmd
    PERL_BADLANG (unset)
    SHELL=C:/bin/bash.exe