Op 6 nov. 2012 11:04 schreef "Jim Michaels" <[email protected]> het
volgende:
>
> somehow I think pointers are the way to go when modifying an iterator
function argument. but I am having problems. I have a pointer to an
iterator.
An iterator is the generalization of pointers for non-sequential
containers. Pass them by value.
>
> gcc wants me to dereference a *third* time. it says to use -> and I know
a->b is the same as *a.b
> but gcc doesn't see it this way I guess. or again I am not understanding
something.
> I already tried doing *iSpecEl->tagName and this does not work. it gives
me an error.
>
> EVERYTHING I have tried gives me an error.
>
> how can this be? I know you dereference iterators using * and same with
pointers. so I had to (I thought) do a double dereference here. here is
latest code:
>
> typedef struct SBraceNode {
> int64_t lineNumber, columnNumber;
> uint32_t ch;
> } SBraceNode;
>
> typedef struct {
> std::string
> name,
> val;
> bool isBoolean;
> VUI hitLineNumbers;
> } SAttribute;
>
>
>
> typedef std::list<SAttribute> LSA;
> typedef std::list<SAttribute>::iterator LSAI;
> typedef std::list<std::string> LS;
> typedef std::list<std::string>::iterator LSI;
> LSA lsGlobalIDs;
>
> typedef std::vector<std::string> VS;
> VS vsDoctypes;
>
> typedef struct SElement {
> std::string tagName;
> bool isVoid; //void element/singleton
> bool isScriptOrStyle; //for these, we ignore any opening and closing
braces and look for </script> tags
> bool hasSlash;
> SBraceNode
> sbnOpenStart, //start of open tag
> sbnOpenEnd, //end of open tag
> sbnCloseStart,//start of close tag
> sbnCloseEnd; //end of close tag
> LS lsAttributes;
> } SElement;
>
> typedef std::vector<SElement> VSE;
> typedef std::vector<SElement>::iterator VSEI;
>
>
> bool attribNameIsInSpecElement(std::string tagName, std::string sattrib,
VSEI* piSpecEl, LSAI* piSpecAttrib, bool isXHTML, bool isXML) {
> //*piSpecEl is the iterator for the spec element
> //**piSpecEl is the element
> //*piSpecAttrib is the iterator for the spec attribute
> //**piSpecAttrib is the attribute
> for (piSpecEl = &(vseSpecElements.begin());
> *piSpecEl != vseSpecElements.end();
> *piSpecEl++) {
> if (compare(tagName,**piSpecEl.tagName,isXHTML,isXML)) {
> for (piSpecAttrib = &(**piSpecEl.lsAttributes.begin());
> *piSpecAttrib != **piSpecEl.lsAttributes.end();
> *piSpecAttrib++) {
> if (compare(**piSpecAttrib.name,sattrib,isXHTML,isXML)) {
> //at this point, iAttrib and iSpecEl both point to
valid attribute and element.
> return true;
> }
> }
> }
> }
> //at this point, iSpecEl points to vseSpecElement.end() and iAttrib
points to lsAttributes.end()
> return false;
> }
>
> I could not use *piSpecEl->tagName because this caused an error.
> I can't use **piSpecEl.tagName because this causes an *error* in gcc and
it says "perhaps you wanted to use -> ?"
This is due to operator precedence. Use parenthesis if you really want to
use double dereferencing.
Ruben
>
> 64\errgw64bmatch2:bmatch2.cpp:405:34: error: request for member 'tagName'
in 'piSpecEl', which is of pointer type 'VSEI* {aka __gnu_cxx::__normal_iter
> ator<SElement*, std::vector<SElement> >*}' (maybe you meant to use '->' ?)
> 64\errgw64bmatch2:bmatch2.cpp:406:37: error: request for member
'lsAttributes' in 'piSpecEl', which is of pointer type 'VSEI* {aka
__gnu_cxx::__normal
> _iterator<SElement*, std::vector<SElement> >*}' (maybe you meant to use
'->' ?)
> 64\errgw64bmatch2:bmatch2.cpp:407:36: error: request for member
'lsAttributes' in 'piSpecEl', which is of pointer type 'VSEI* {aka
__gnu_cxx::__normal
> _iterator<SElement*, std::vector<SElement> >*}' (maybe you meant to use
'->' ?)
> 64\errgw64bmatch2:bmatch2.cpp:409:32: error: request for member 'name' in
'piSpecAttrib', which is of pointer type 'LSAI* {aka std::_List_iterator<SAt
> tribute>*}' (maybe you meant to use '->' ?)
>
>
>
>
>> ________________________________
>> From: Ruben Van Boxem <[email protected]>
>> To: [email protected]
>> Sent: Monday, November 5, 2012 11:52 PM
>> Subject: Re: [Mingw-w64-public] bug in gcc? has nothing defined for
iterator references
>>
>> Op 6 nov. 2012 06:40 schreef "Jim Michaels" <[email protected]> het
volgende:
>> >
>> > 32\errgw32bmatch2:bmatch2.cpp:404:49: error: no match for 'operator='
in 'iSpecAttrib = (& iSpecEl)->__gnu_cxx::__normal_iterator<_Iterator,
_Container>::operator-><SElement*, std::vector<SElement>
>()->SElement::lsAttributes.std::list<_Tp,
_Alloc>::begin<std::basic_string<char>,
std::allocator<std::basic_string<char> > >()'
>> >
>> > 32\errgw32bmatch2:bmatch2.cpp:404:93: error: no match for 'operator!='
in 'iSpecAttrib != (& iSpecEl)->__gnu_cxx::__normal_iterator<_Iterator,
_Container>::operator-><SElement*, std::vector<SElement>
>()->SElement::lsAttributes.std::list<_Tp,
_Alloc>::end<std::basic_string<char>,
std::allocator<std::basic_string<char> > >()'
>> >
>> > typedef struct {
>> > std::string
>> > name,
>> > val;
>> > bool isBoolean;
>> > VUI hitLineNumbers;
>> > } SAttribute;
>> > typedef std::list<SAttribute> LSA;
>> > typedef std::list<SAttribute>::iterator LSAI;
>> >
>> > bool attribNameIsInSpecElement(std::string tagName, std::string
attrib, VSEI& iSpecEl, LSAI& iSpecAttrib, bool isXHTML, bool isXML) {
>> Why are you passing the iterator references into the function when you
set them below anyway? Remove these function parameters, and make the
variables local to their for loop.
>> > for (iSpecEl=vseSpecElements.begin(); iSpecEl !=
vseSpecElements.end(); iSpecEl++) {
>> > if (compare(tagName,iSpecEl->tagName,isXHTML,isXML)) {
>> > for (iSpecAttrib=iSpecEl->lsAttributes.begin();
iSpecAttrib != iSpecEl->lsAttributes.end(); iSpecAttrib++) {
>> >
>> >
>> > where it's having trouble is with assigning and equating to LSAI
variables. specifically last and first line of function nothing is defined
as operators for any iterator that's a reference.
>> >
>> > maybe there's something I am missing here. I wanted to modify the
original iSpecAttrib.
>> > I don't know enough about iterators to figure out how to pass a value
back in an argument to the original variable in c++ now except to use
pointers...
>> > I really wanted to use references, they are SO much more convenient.
>> It is idiomatic c++ to pass iterators by value, not by reference.
>> Ruben
>> >
>> > -------------
>> > Jim Michaels
>> > [email protected]
>> > [email protected]
>> > http://RenewalComputerServices.com
>> > http://JesusnJim.com (my personal site, has software)
>> > ---
>> > IEC Units: Computer RAM & SSD measurements, microsoft disk size
measurements (note: they will say GB or MB or KB or TB when it is IEC
Units!):
>> > [KiB] [MiB] [GiB] [TiB]
>> > [2^10B=1,024^1B=1KiB]
>> > [2^20B=1,024^2B=1,048,576B=1MiB]
>> > [2^30B=1,024^3B=1,073,741,824B=1GiB]
>> > [2^40B=1,024^4B=1,099,511,627,776B=1TiB]
>> > [2^50B=1,024^5B=1,125,899,906,842,624B=1PiB]
>> > SI Units: Hard disk industry disk size measurements:
>> > [KB] [MB] [GB] [TB]
>> > [10^3B=1,000B=1KB]
>> > [10^6B=1,000,000B=1MB]
>> > [10^9B=1,000,000,000B=1GB]
>> > [10^12B=1,000,000,000,000B=1TB]
>> > [10^15B=1,000,000,000,000,000B=1PB]
>> >
>> >
>> >
------------------------------------------------------------------------------
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>> > _______________________________________________
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>> > [email protected]
>> > https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
>> >
>>
>>
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>
>
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