using templates and map

[Stoian]

hey how is it goin,
i've got this problem - declared a template but it doesn't work
properly, here is the code:

53 std::map<Config , Config> seen;
54 Config new();
55 seen.insert(new , new);

i need to do it that way but the code brakes when i write the command
"seen.insert(ne w, new);"

i can assure you that everything else is working, just this - > i've
declared the template properly, cause i've used it in other parts of
the code, and i've also included the <map> library. by the way this is
the error, that i get - i also can't understand the error:

bash-2.05$ make
g++ -ggdb -c clock.cpp
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:
In member function `void std::_Rb_tree<_ Key, _Val, _KeyOfValue,
_Compare, _Alloc>::insert _unique(_II, _II) [with _InputIterator =
ClockConfig (*)(), _Key = ClockConfig, _Val = std::pair<const
ClockConfig, ClockConfig>, _KeyOfValue =
std::_Select1st <std::pair<cons t ClockConfig, ClockConfig> >, _Compare
= std::less<Clock Config>, _Alloc = std::allocator< std::pair<const
ClockConfig, ClockConfig> >]':
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_map.h:397:
instantiated from `void std::map<_Key, _Tp, _Compare,
_Alloc>::insert (_InputIterator , _InputIterator) [with _InputIterator =
ClockConfig (*)(), _Key = ClockConfig, _Tp = ClockConfig, _Compare =
std::less<Clock Config>, _Alloc = std::allocator< std::pair<const
ClockConfig, ClockConfig> >]'
Solver.cpp:55: instantiated from `void Solver<Config>: :solve() [with
Config = ClockConfig]'
clock.cpp:60: instantiated from here
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:993:
error: ISO C++ forbids incrementing a pointer of type `ClockConfig
(*)()'
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:994:
error: no matching function for call to `std::_Rb_tree< ClockConfig,
std::pair<const ClockConfig, ClockConfig>,
std::_Select1st <std::pair<cons t ClockConfig, ClockConfig> >,
std::less<Clock Config>, std::allocator< std::pair<const ClockConfig,
ClockConfig> > >::insert_uniqu e(ClockConfig (&)())'
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:862:
note: candidates are: std::pair<typen ame std::_Rb_tree<_ Key, _Val,
_KeyOfValue, _Compare, _Alloc>::iterat or, bool> std::_Rb_tree<_ Key,
_Val, _KeyOfValue, _Compare, _Alloc>::insert _unique(const _Val&) [with
_Key = ClockConfig, _Val = std::pair<const ClockConfig, ClockConfig>,
_KeyOfValue = std::_Select1st <std::pair<cons t ClockConfig,
ClockConfig> >, _Compare = std::less<Clock Config>, _Alloc =
std::allocator< std::pair<const ClockConfig, ClockConfig> >]
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:888:
note: typename std::_Rb_tree<_ Key, _Val, _KeyOfValue,
_Compare, _Alloc>::iterat or std::_Rb_tree<_ Key, _Val, _KeyOfValue,
_Compare, _Alloc>::insert _unique(std::_R b_tree_iterator <_Val>, const
_Val&) [with _Key = ClockConfig, _Val = std::pair<const ClockConfig,
ClockConfig>, _KeyOfValue = std::_Select1st <std::pair<cons t
ClockConfig, ClockConfig> >, _Compare = std::less<Clock Config>, _Alloc
= std::allocator< std::pair<const ClockConfig, ClockConfig> >]
*** Error code 1
make: Fatal error: Command failed for target `clock.o'
any help will be really appreciated!!!!
thanks a lot!!!

[Gianni Mariani]

Stoian wrote:

hey how is it goin,
i've got this problem - declared a template but it doesn't work
properly, here is the code:

53 std::map<Config , Config> seen;
54 Config new();
This defines a function called new() that returns a Config (prolly not
what you want).
55 seen.insert(new , new);
Inserting a function ?

i need to do it that way but the code brakes when i write the command
"seen.insert(ne w, new);"

i can assure you that everything else is working, just this - > i've
declared the template properly, cause i've used it in other parts of
the code, and i've also included the <map> library. by the way this is
the error, that i get - i also can't understand the error:

error snipped ... basically is says.

You're trying to call ...
....::insert_un ique(ClockConfi g (&)())

But a :
....::insert_un ique(const _Val&)

is the only candidate.

[Anatoly Shirokov]

> 53 std::map<Config , Config> seen;

54 Config foo;
55 seen.insert(std ::make_pair(foo , foo));

new - key word
Config foo() - declaration of function

[John Harrison]

"Stoian" <sp*****@yahoo. com> wrote in message
news:4a******** *************** ***@posting.goo gle.com...

hey how is it goin,
i've got this problem - declared a template but it doesn't work
properly, here is the code:

53 std::map<Config , Config> seen;
54 Config new();
55 seen.insert(new , new);

1) new is not a legal name for a variable.
2) don't put backets after the variable name, that makes it a function.
3) you have to make a pair to insert into a map

std::map<Config , Config> seen;
Config noo;
seen.insert(std ::make_pair(noo , noo));

That should compile.

john

[Stoian]

thanks a lot, i actually didn't notice when i writing these 3 lines
here, so i just put "new" and didn't realise (i didn't actually paste
the code). Ok i tried the make pair, and i still have errors, I'm not
that good with using templates, but i think that the problem is with
defining a comparator, probably the default one doesn't work with
templates, i don't know.
Here is what i did, and the error again:

50 Config temp;
51 std::map<Config , Config> seen;
52 seen.insert(std ::make_pair(tem p, temp));
bash-2.05$ make
g++ -ggdb -c change.cpp
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/
bits/stl_function.h: In member function `bool
std::less<_Tp>: :operator()(con st _
Tp&, const _Tp&) const [with _Tp = ChangeConfig]':
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/
bits/stl_tree.h:869: instantiated from `std::pair<type name
std::_Rb_tree<_ Key,
_Val, _KeyOfValue, _Compare, _Alloc>::iterat or, bool>
std::_Rb_tree<_ Key, _Val,
_KeyOfValue, _Compare, _Alloc>::insert _unique(const _Val&) [with _Key
= ChangeC
onfig, _Val = std::pair<const ChangeConfig, ChangeConfig>, _KeyOfValue
= std::_S
elect1st<std::p air<const ChangeConfig, ChangeConfig> >, _Compare =
std::less<Cha
ngeConfig>, _Alloc = std::allocator< std::pair<const ChangeConfig,
ChangeConfig>

]' /usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/
bits/stl_map.h:360: instantiated from `std::pair<type name
std::_Rb_tree<_ Key,
std::pair<const _Key, _Tp>, std::_Select1st <std::pair<cons t _Key, _Tp>, _Compa

re, _Alloc>::iterat or, bool> std::map<_Key, _Tp, _Compare,
_Alloc>::insert (const
std::pair<const _Key, _Tp>&) [with _Key = ChangeConfig, _Tp =
ChangeConfig, _Co
mpare = std::less<Chang eConfig>, _Alloc =
std::allocator< std::pair<const ChangeC
onfig, ChangeConfig> >]'
Solver.cpp:52: instantiated from `void Solver<Config>: :solve() [with
Config =
ChangeConfig]'
change.cpp:64: instantiated from here
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/
bits/stl_function.h: 227: error: no match for 'operator<' in '__x <
__y'
*** Error code 1
make: Fatal error: Command failed for target `change.o'
bash-2.05$
thanks again for your help

[Victor Bazarov]

"Stoian" <sp*****@yahoo. com> wrote...

thanks a lot, i actually didn't notice when i writing these 3 lines
here, so i just put "new" and didn't realise (i didn't actually paste
the code). Ok i tried the make pair, and i still have errors, I'm not
that good with using templates, but i think that the problem is with
defining a comparator, probably the default one doesn't work with
templates, i don't know.
Here is what i did, and the error again:

50 Config temp;
51 std::map<Config , Config> seen;
52 seen.insert(std ::make_pair(tem p, temp));

[...]
bits/stl_function.h: 227: error: no match for 'operator<' in '__x <
__y'
*** Error code 1

Does your 'Config' class have operator< defined for it or in it? If not,
you cannot use it as the key in a map unless you define your own special
comparison functor. If you know how to compare two 'Config' objects,
then defining operator< is probably easier than anything else.

Victor

[Zeng Dinghao]

You should define 'new' like this:

Config new;

rather than

Config new();

where the latter means 'define a funtion named new with void parameter list
and return Config'.

"Stoian" <sp*****@yahoo. com>
??????:4a****** *************** *****@posting.g oogle.com...

hey how is it goin,
i've got this problem - declared a template but it doesn't work
properly, here is the code:

53 std::map<Config , Config> seen;
54 Config new();
55 seen.insert(new , new);

i need to do it that way but the code brakes when i write the command
"seen.insert(ne w, new);"

i can assure you that everything else is working, just this - > i've
declared the template properly, cause i've used it in other parts of
the code, and i've also included the <map> library. by the way this is
the error, that i get - i also can't understand the error:

bash-2.05$ make
g++ -ggdb -c clock.cpp
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:
In member function `void std::_Rb_tree<_ Key, _Val, _KeyOfValue,
_Compare, _Alloc>::insert _unique(_II, _II) [with _InputIterator =
ClockConfig (*)(), _Key = ClockConfig, _Val = std::pair<const
ClockConfig, ClockConfig>, _KeyOfValue =
std::_Select1st <std::pair<cons t ClockConfig, ClockConfig> >, _Compare
= std::less<Clock Config>, _Alloc = std::allocator< std::pair<const
ClockConfig, ClockConfig> >]':
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_map.h:397:
instantiated from `void std::map<_Key, _Tp, _Compare,
_Alloc>::insert (_InputIterator , _InputIterator) [with _InputIterator =
ClockConfig (*)(), _Key = ClockConfig, _Tp = ClockConfig, _Compare =
std::less<Clock Config>, _Alloc = std::allocator< std::pair<const
ClockConfig, ClockConfig> >]'
Solver.cpp:55: instantiated from `void Solver<Config>: :solve() [with
Config = ClockConfig]'
clock.cpp:60: instantiated from here
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:993:
error: ISO C++ forbids incrementing a pointer of type `ClockConfig
(*)()'
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:994:
error: no matching function for call to `std::_Rb_tree< ClockConfig,
std::pair<const ClockConfig, ClockConfig>,
std::_Select1st <std::pair<cons t ClockConfig, ClockConfig> >,
std::less<Clock Config>, std::allocator< std::pair<const ClockConfig,
ClockConfig> > >::insert_uniqu e(ClockConfig (&)())'
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:862:
note: candidates are: std::pair<typen ame std::_Rb_tree<_ Key, _Val,
_KeyOfValue, _Compare, _Alloc>::iterat or, bool> std::_Rb_tree<_ Key,
_Val, _KeyOfValue, _Compare, _Alloc>::insert _unique(const _Val&) [with
_Key = ClockConfig, _Val = std::pair<const ClockConfig, ClockConfig>,
_KeyOfValue = std::_Select1st <std::pair<cons t ClockConfig,
ClockConfig> >, _Compare = std::less<Clock Config>, _Alloc =
std::allocator< std::pair<const ClockConfig, ClockConfig> >]
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/bits/stl_tree.h:888:
note: typename std::_Rb_tree<_ Key, _Val, _KeyOfValue,
_Compare, _Alloc>::iterat or std::_Rb_tree<_ Key, _Val, _KeyOfValue,
_Compare, _Alloc>::insert _unique(std::_R b_tree_iterator <_Val>, const
_Val&) [with _Key = ClockConfig, _Val = std::pair<const ClockConfig,
ClockConfig>, _KeyOfValue = std::_Select1st <std::pair<cons t
ClockConfig, ClockConfig> >, _Compare = std::less<Clock Config>, _Alloc
= std::allocator< std::pair<const ClockConfig, ClockConfig> >]
*** Error code 1
make: Fatal error: Command failed for target `clock.o'
any help will be really appreciated!!!!
thanks a lot!!!

[Rolf Magnus]

Stoian wrote:

thanks a lot, i actually didn't notice when i writing these 3 lines
here, so i just put "new" and didn't realise (i didn't actually paste
the code). Ok i tried the make pair, and i still have errors, I'm not
that good with using templates, but i think that the problem is with
defining a comparator, probably the default one doesn't work with
templates, i don't know.
The default one uses operator<, so your key type needs an operator<.
Here is what i did, and the error again:

50 Config temp;
51 std::map<Config , Config> seen;
52 seen.insert(std ::make_pair(tem p, temp));
bash-2.05$ make
g++ -ggdb -c change.cpp
....
/usr/local/gnu/lib/gcc/sparc-sun-solaris2.9/3.4.1/../../../../include/c++/3.4.1/
bits/stl_function.h: 227: error: no match for 'operator<' in '__x <
__y'
*** Error code 1

The compiler is telling you that your key type (i.e. Config) doesn't have an
operator<. So you either need to use your own custom comparison
function/object or you need to overload operator< that compares two
instances of your Config class.