Multipmap of pointers, sort by key

[karen.b.lin]

I've created a multimap of pointers. The sort order by key seems
messed up.

ex:

std::multimap<B OMBImntRT*, BOMBPortfolio*u ndPortMap;

I did not try to create multimap of objects instead, b/c some classes
do not have copy constructors, and it'll be very messy to create one.

Is there anyway to have the pointer multimap sorted?

New at this ... appreciate your help~

[Obnoxious User]

ka*********@gma il.com skrev:

I've created a multimap of pointers. The sort order by key seems
messed up.

How so?

[karen.b.lin]

On Apr 10, 1:22 pm, Obnoxious User <O...@127.0.0.1 wrote:

karen.b....@gma il.com skrev:

I've created a multimap of pointers. The sort order by key seems
messed up.

How so?

the key is an instrument, operator < is on the name of the instrument.

Here's an example of the map:

Instrument Portfolio
AMD P1
MOTOROLA P1
PACIFIC ETHANOL P1
MERRILL LYNCH P2
MOTOROLA P2
Even tho and line 2 and line 5, both keys are motorola, when i print
them out, it's not sorted by the Instrument.
The order seems to be the insert order.

[Obnoxious User]

ka*********@gma il.com skrev:

On Apr 10, 1:22 pm, Obnoxious User <O...@127.0.0.1 wrote:

>karen.b....@gm ail.com skrev:

>>I've created a multimap of pointers. The sort order by key seems
messed up.

How so?

the key is an instrument, operator < is on the name of the instrument.

Here's an example of the map:

Instrument Portfolio
AMD P1
MOTOROLA P1
PACIFIC ETHANOL P1
MERRILL LYNCH P2
MOTOROLA P2
Even tho and line 2 and line 5, both keys are motorola, when i print
them out, it's not sorted by the Instrument.
The order seems to be the insert order.

With pointers as keys, it will by default sort using pointer addresses.
Add your own sorting functor to sort it the way you want.

struct my_sort {
bool operator()(BOMB ImntRT * a, BOMBImntRT * b) {
return a->some_value < b->some_value;
}
};

std::multimap<B OMBImntRT*, BOMBPortfolio*, my_sortundPortM ap;

[Obnoxious User]

Obnoxious User skrev:

ka*********@gma il.com skrev:

>On Apr 10, 1:22 pm, Obnoxious User <O...@127.0.0.1 wrote:

>>karen.b....@g mail.com skrev:

I've created a multimap of pointers. The sort order by key seems
messed up.
How so?

the key is an instrument, operator < is on the name of the instrument.

Here's an example of the map:

Instrument Portfolio
AMD P1
MOTOROLA P1
PACIFIC ETHANOL P1
MERRILL LYNCH P2
MOTOROLA P2
Even tho and line 2 and line 5, both keys are motorola, when i print
them out, it's not sorted by the Instrument.
The order seems to be the insert order.

With pointers as keys, it will by default sort using pointer addresses.
Add your own sorting functor to sort it the way you want.

struct my_sort {
bool operator()(BOMB ImntRT * a, BOMBImntRT * b) {
return a->some_value < b->some_value;

Or if you already have operator< defined

return *a < *b;

}
};

std::multimap<B OMBImntRT*, BOMBPortfolio*, my_sortundPortM ap;

--
OU

[Roland Pibinger]

On Tue, 10 Apr 2007 19:47:25 +0200, Obnoxious User wrote:

>With pointers as keys, it will by default sort using pointer addresses.

.... because STL was designed only for values. For pointers you need
workarounds.

>Add your own sorting functor to sort it the way you want.

struct my_sort {
bool operator()(BOMB ImntRT * a, BOMBImntRT * b) {

bool operator()(cons t BOMBImntRT * a, const BOMBImntRT * b) const {

return a->some_value < b->some_value;
}
};

std::multimap< BOMBImntRT*, BOMBPortfolio*, my_sortundPortM ap;

--
Roland Pibinger
"The best software is simple, elegant, and full of drama" - Grady Booch

[karen.b.lin]

On Apr 10, 2:50 pm, rpbg...@yahoo.c om (Roland Pibinger) wrote:

On Tue, 10 Apr 2007 19:47:25 +0200, Obnoxious User wrote:

With pointers as keys, it will by default sort using pointer addresses.

... because STL was designed only for values. For pointers you need
workarounds.

Add your own sorting functor to sort it the way you want.

struct my_sort {
bool operator()(BOMB ImntRT * a, BOMBImntRT * b) {

bool operator()(cons t BOMBImntRT * a, const BOMBImntRT * b) const {

return a->some_value < b->some_value;
}
};

std::multimap<B OMBImntRT*, BOMBPortfolio*, my_sortundPortM ap;

Thanks for the reply

A stupid question ... why are we overloading opeartor ()?

struct UnderlyingsPtrS orter
{
bool operator() (BOMBImntRT* a, BOMBImntRT* b){
return a->ImntName < b->ImntName;
}
};
std::multimap<B OMBImntRT*, BOMBPortfolio*, UnderlyingsPtrS orter>
undPortMap;
std::multimap<B OMBImntRT*, BOMBPosition*, UnderlyingsPtrS orter>
undPosMap;

std::multimap<B OMBImntRT*, BOMBPortfolio*,
UnderlyingsPtrS orter::iterator undPortIt;
std::multimap<B OMBImntRT*, BOMBPosition*,
UnderlyingsPtrS orter::iterator undPosIt;

I'm getting these compiling errors:

c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(518) : error C2662: '()' : cannot convert 'this'
pointer from 'const struct UnderlyingsPtrS orter' to 'struct
UnderlyingsPtrS orter &'
Conversion loses qualifiers
c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(514) : while compiling class-template member
function 'struct std::_Tree<clas s BOMBImntRT *,struct std::pair<class
BOMBImntRT * const,class BOMBPosition *>,struct
std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>

>::_Kfn,struc t UnderlyingsPtrS orter,class std::allocator< class

BOMBPosition *::_Node *__thiscall std::_Tree<clas s BOMBIm
ntRT *,struct std::pair<class BOMBImntRT * const,class BOMBPosition
*>,struct std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>

>::_Kfn,struc t UnderlyingsPtrS orter,class std:

:allocator<clas s BOMBPosition *::_Lbound(clas s BOMBImntRT *const
& ) const'
c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(518) : error C2064: term does not evaluate to a
function
c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(514) : while compiling class-template member
function 'struct std::_Tree<clas s BOMBImntRT *,struct std::pair<class
BOMBImntRT * const,class BOMBPosition *>,struct
std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>

>::_Kfn,struc t UnderlyingsPtrS orter,class std::allocator< class

BOMBPosition *::_Node *__thiscall std::_Tree<clas s BOMBIm
ntRT *,struct std::pair<class BOMBImntRT * const,class BOMBPosition
*>,struct std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>

>::_Kfn,struc t UnderlyingsPtrS orter,class std:

:allocator<clas s BOMBPosition *::_Lbound(clas s BOMBImntRT *const
& ) const'
Error executing cl.exe.

[karen.b.lin]

On Apr 11, 10:27 am, "karen.b....@gm ail.com" <karen.b....@gm ail.com>
wrote:

On Apr 10, 2:50 pm, rpbg...@yahoo.c om (Roland Pibinger) wrote:

On Tue, 10 Apr 2007 19:47:25 +0200, Obnoxious User wrote:

>With pointers as keys, it will by default sort using pointer addresses.

... because STL was designed only for values. For pointers you need
workarounds.

>Add your own sorting functor to sort it the way you want.

>struct my_sort {
bool operator()(BOMB ImntRT * a, BOMBImntRT * b) {

bool operator()(cons t BOMBImntRT * a, const BOMBImntRT * b) const {

return a->some_value < b->some_value;
}
>};

>std::multimap< BOMBImntRT*, BOMBPortfolio*, my_sortundPortM ap;

Thanks for the reply

A stupid question ... why are we overloading opeartor ()?

struct UnderlyingsPtrS orter
{
bool operator() (BOMBImntRT* a, BOMBImntRT* b){
return a->ImntName < b->ImntName;
}

};

std::multimap<B OMBImntRT*, BOMBPortfolio*, UnderlyingsPtrS orter>
undPortMap;
std::multimap<B OMBImntRT*, BOMBPosition*, UnderlyingsPtrS orter>
undPosMap;

std::multimap<B OMBImntRT*, BOMBPortfolio*,
UnderlyingsPtrS orter::iterator undPortIt;
std::multimap<B OMBImntRT*, BOMBPosition*,
UnderlyingsPtrS orter::iterator undPosIt;

I'm getting these compiling errors:

c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(518) : error C2662: '()' : cannot convert 'this'
pointer from 'const struct UnderlyingsPtrS orter' to 'struct
UnderlyingsPtrS orter &'
Conversion loses qualifiers
c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(514) : while compiling class-template member
function 'struct std::_Tree<clas s BOMBImntRT *,struct std::pair<class
BOMBImntRT * const,class BOMBPosition *>,struct
std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>>::_Kfn,struc t UnderlyingsPtrS orter,class std::allocator< class

BOMBPosition *::_Node *__thiscall std::_Tree<clas s BOMBIm
ntRT *,struct std::pair<class BOMBImntRT * const,class BOMBPosition
*>,struct std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>>::_Kfn,struc t UnderlyingsPtrS orter,class std:

:allocator<clas s BOMBPosition *::_Lbound(clas s BOMBImntRT *const
& ) const'
c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(518) : error C2064: term does not evaluate to a
function
c:\program files\microsoft visual studio enterprise edition
\vc98\include\x tree(514) : while compiling class-template member
function 'struct std::_Tree<clas s BOMBImntRT *,struct std::pair<class
BOMBImntRT * const,class BOMBPosition *>,struct
std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>>::_Kfn,struc t UnderlyingsPtrS orter,class std::allocator< class

BOMBPosition *::_Node *__thiscall std::_Tree<clas s BOMBIm
ntRT *,struct std::pair<class BOMBImntRT * const,class BOMBPosition
*>,struct std::multimap<c lass BOMBImntRT *,class BOMBPosition *,struct
UnderlyingsPtrS orter,class std::allocator< class BOMBPosition *>>::_Kfn,struc t UnderlyingsPtrS orter,class std:

:allocator<clas s BOMBPosition *::_Lbound(clas s BOMBImntRT *const
& ) const'
Error executing cl.exe.- Hide quoted text -

- Show quoted text -

Never mind ... It worked after I add the const
struct UnderlyingsPtrS orter
{
bool operator() (const BOMBImntRT* a, const BOMBImntRT* b) const{
return a->ImntName < b->ImntName;
}
};

But still don't get why overloading () ?

[Marco Wahl]

With pointers as keys, it will by default sort using pointer addresses.
... because STL was designed only for values. For pointers you need
workarounds.
Add your own sorting functor to sort it the way you want.

struct my_sort {
bool operator()(BOMB ImntRT * a, BOMBImntRT * b) {

bool operator()(cons t BOMBImntRT * a, const BOMBImntRT * b) const {

return a->some_value < b->some_value;
}
};

std::multimap<B OMBImntRT*, BOMBPortfolio*, my_sortundPortM ap;

Thanks for the reply

A stupid question ... why are we overloading opeartor ()?

[...]

But still don't get why overloading () ?

The comparision obviously needs two parameters for work. And this is
realized by a something that looks like a function that accepts two
parameters. E.g.

void my_sort(BOMBImn tRT* a, BOMBImntRT* b);

or

struct my_sort
{
void operator(BOMBIm ntRT*, BOMBImntRT*);
}

hth

[Marco Wahl]

On Apr 11, 6:34 pm, "Marco Wahl" <marco.w...@gma il.comwrote:

>With pointers as keys, it will by default sort using pointer addresses.
... because STL was designed only for values. For pointers you need
workarounds.
>Add your own sorting functor to sort it the way you want.

>struct my_sort {
bool operator()(BOMB ImntRT * a, BOMBImntRT * b) {

bool operator()(cons t BOMBImntRT * a, const BOMBImntRT * b) const {

return a->some_value < b->some_value;
}
>};

>std::multimap< BOMBImntRT*, BOMBPortfolio*, my_sortundPortM ap;

Thanks for the reply

A stupid question ... why are we overloading opeartor ()?

[...]
But still don't get why overloading () ?

The comparision obviously needs two parameters for work. And this is
realized by a something that looks like a function that accepts two
parameters. E.g.

void my_sort(BOMBImn tRT* a, BOMBImntRT* b);

or

struct my_sort
{
void operator(BOMBIm ntRT*, BOMBImntRT*);

void operator()(BOMB ImntRT*, BOMBImntRT*);

>
}

Quick fix, sorry.