Some problems with std::vector and nested templates

[jubelbrus]

Hi

I'm trying to do the following.

#include <vector>
#include <boost/thread/mutex.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/tuple/tuple.hpp>

class {
boost::mutex m_lock;
std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T >
m_vector;

template <class Tboost::shared_ ptr<Tlist::<T>g etitem(uint32_t id)
{
boost::mutex::s coped_lock lock(m_lock);

std::vector< boost::tuple<ui nt32_t, boost::shared_p tr<T

>::iterator pos =

find_if(m_vecto r.begin(), m_vector.end(), compare_list<T> (id),
m_vector.begin( ));

if (pos != m_vector.end())
return *pos;

return boost::shared_p tr(NULL);
};

but I get the following error
error: expected ';' before 'pos'

I don't understand why I'm getting this error because the definition
of std::vector works, it's just the iterator statement that doesn't.

[Robert Bauck Hamar]

Re: Some problems with std::vector and nested templates

jubelbrus wrote:

Hi
>
I'm trying to do the following.
>
#include <vector>
#include <boost/thread/mutex.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/tuple/tuple.hpp>
>
class {
boost::mutex m_lock;
std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T >
m_vector;

I'm assuming uint32_t might be typedefed somewhere.
What's T? This is not a template?

template <class Tboost::shared_ ptr<Tlist::<T>g etitem(uint32_t id)

huh?
template <class T>
boost::shared_p tr<T>
list<T>::getite m(uint32_t id)
?
What's list?

{
boost::mutex::s coped_lock lock(m_lock);
>
std::vector< boost::tuple<ui nt32_t, boost::shared_p tr<T

>>::iterator pos =

find_if(m_vecto r.begin(), m_vector.end(), compare_list<T> (id),
m_vector.begin( ));

typename std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T

>::iterator pos = find_if(...)

You need typename here, because vector< ... is dependent on T.

if (pos != m_vector.end())
return *pos;

*pos is a tuple, not a shared_ptr

return boost::shared_p tr(NULL);
};
>
but I get the following error
error: expected ';' before 'pos'
>
I don't understand why I'm getting this error because the definition
of std::vector works, it's just the iterator statement that doesn't.

--
rbh

[jubelbrus]

Re: Some problems with std::vector and nested templates

Sorry about the misspellings...

This is what I'm trying to do:
Write a template class that stores a list of boost::shared_p tr<Twith
a index and is thread safe, where T would be that template <class T>
stuff..

I got the getitem function compiling by using typename, tanks.. but
I've discovered some compile problems with my insert code.

#include <stdint.h>
#include <vector>
#include <boost/thread/mutex.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/tuple/tuple.hpp>

template <class T>
class list{
boost::mutex m_lock;
std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T >
m_vector;

uint32_t m_nextid;

uint32_t insert(boost::s hared_ptr<T>);
}

template <class T>
uint32_t list<T>::insert (boost::shared_ ptr<T>)
{
typename boost::tuples:: tuple<uint32_t, boost::shared_p tr<T
add_item(m_next id, item);
typename std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T

m_vector;

boost::mutex::s coped_lock lock(m_lock);

m_vector.insert ( add_item );
return m_nextid++;

};

I get the following error:
list.h: In member function 'uint32_t
stdtools::list< T>::insert(boos t::shared_ptr<T >) [with T = int]':
tester_a.cpp:10 : instantiated from here
list.h:90: error: no matching function for call to
'std::vector<bo ost::tuples::tu ple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>,
std::allocator< boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type

>::insert(boost ::tuples::tuple <uint32_t, boost::shared_p tr<int>,

boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>&)'
/usr/include/c++/4.0.0/bits/vector.tcc:93: note: candidates are:
typename std::vector<_Tp , _Alloc>::iterat or std::vector<_Tp ,
_Alloc>::insert (__gnu_cxx::__n ormal_iterator< typename _Alloc::pointer ,
std::vector<_Tp , _Alloc, const _Tp&) [with _Tp =
boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>, _Alloc =
std::allocator< boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type]
/usr/include/c++/4.0.0/bits/stl_vector.h:65 7: note:
void std::vector<_Tp ,
_Alloc>::insert (__gnu_cxx::__n ormal_iterator< typename _Alloc::pointer ,
std::vector<_Tp , _Alloc, size_t, const _Tp&) [with _Tp =
boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>, _Alloc =
std::allocator< boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type]

Anybody??

[John Harrison]

Re: Some problems with std::vector and nested templates

jubelbrus wrote:

Sorry about the misspellings...
>
This is what I'm trying to do:
Write a template class that stores a list of boost::shared_p tr<Twith
a index and is thread safe, where T would be that template <class T>
stuff..
>
I got the getitem function compiling by using typename, tanks.. but
I've discovered some compile problems with my insert code.
>
#include <stdint.h>
#include <vector>
#include <boost/thread/mutex.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/tuple/tuple.hpp>
>
template <class T>
class list{
boost::mutex m_lock;
std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T >
m_vector;
>
uint32_t m_nextid;
>
uint32_t insert(boost::s hared_ptr<T>);
}
>
template <class T>
uint32_t list<T>::insert (boost::shared_ ptr<T>)
{
typename boost::tuples:: tuple<uint32_t, boost::shared_p tr<T
add_item(m_next id, item);
typename std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T

>m_vector;

>
boost::mutex::s coped_lock lock(m_lock);
>
m_vector.insert ( add_item );

Perhaps you mean

m_vector.push_b ack( add_item );

There is no method of vector called insert that takes a single argument.

john

[jubelbrus]

Re: Some problems with std::vector and nested templates

On 17 Jun, 17:49, John Harrison <john_androni.. .@hotmail.comwr ote:

jubelbrus wrote:

Sorry about the misspellings...

>

This is what I'm trying to do:
Write a template class that stores a list of boost::shared_p tr<Twith
a index and is thread safe, where T would be that template <class T>
stuff..

>

I got the getitem function compiling by using typename, tanks.. but
I've discovered some compile problems with my insert code.

>

#include <stdint.h>
#include <vector>
#include <boost/thread/mutex.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/tuple/tuple.hpp>

>

template <class T>
class list{
boost::mutex m_lock;
std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T >
m_vector;

>

uint32_t m_nextid;

>

uint32_t insert(boost::s hared_ptr<T>);
}

>

template <class T>
uint32_t list<T>::insert (boost::shared_ ptr<T>)
{
typename boost::tuples:: tuple<uint32_t, boost::shared_p tr<T
add_item(m_next id, item);
typename std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T

m_vector;

>

boost::mutex::s coped_lock lock(m_lock);

>

m_vector.insert ( add_item );

>
Perhaps you mean
>
m_vector.push_b ack( add_item );
>
There is no method of vector called insert that takes a single argument.
>
john

oh... :)

thanks

[Robert Bauck Hamar]

Re: Some problems with std::vector and nested templates

jubelbrus wrote:

Sorry about the misspellings...
>
This is what I'm trying to do:
Write a template class that stores a list of boost::shared_p tr<Twith
a index and is thread safe, where T would be that template <class T>
stuff..
>
I got the getitem function compiling by using typename, tanks.. but
I've discovered some compile problems with my insert code.
>
#include <stdint.h>
#include <vector>
#include <boost/thread/mutex.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/tuple/tuple.hpp>
>
template <class T>
class list{
boost::mutex m_lock;
std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T >
m_vector;
>
uint32_t m_nextid;
>
uint32_t insert(boost::s hared_ptr<T>);
}
>
template <class T>
uint32_t list<T>::insert (boost::shared_ ptr<T>)
{
typename boost::tuples:: tuple<uint32_t, boost::shared_p tr<T
add_item(m_next id, item);

There should be no typename here.

typename std::vector<boo st::tuple<uint3 2_t, boost::shared_p tr<T

>m_vector;

nor here.

typename are needed in:
T::something
or
someclass<T>::s omething
To put it very short.

This is because the compiler cannot possibly know what something is. The
first is obvious. The second:

template <class T>
class someclass {
public:
typedef T something;
};

int p;

template <class T>
void foo() {
someclass<T>::s omething * p; /*Missing typename and definition of local p
or multiplication? Standard says multiplication */
}

template <>
class someclass<int{
public:
int something;
};

int someclass<int>: :something = 3;

int main() {
p = 42;
foo<int>();
}

boost::mutex::s coped_lock lock(m_lock);
>
m_vector.insert ( add_item );
return m_nextid++;
>
};
>
I get the following error:
list.h: In member function 'uint32_t
stdtools::list< T>::insert(boos t::shared_ptr<T >) [with T = int]':
tester_a.cpp:10 : instantiated from here
list.h:90: error: no matching function for call to

// beginning

'std::vector<bo ost::tuples::tu ple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>,
std::allocator< boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type

>>::insert(boos t::tuples::tupl e<uint32_t, boost::shared_p tr<int>,

boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>&)'

//end

Shorter:
std::vector<... >::insert(tuple <...>)

/usr/include/c++/4.0.0/bits/vector.tcc:93: note: candidates are:

//beginning

typename std::vector<_Tp , _Alloc>::iterat or std::vector<_Tp ,
_Alloc>::insert (__gnu_cxx::__n ormal_iterator< typename _Alloc::pointer ,
std::vector<_Tp , _Alloc, const _Tp&) [with _Tp =
boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>, _Alloc =
std::allocator< boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type]

//end
shorter:
std::vector<... >::insert(std:: vector<...>::it erator, const tuple<...>&)

/usr/include/c++/4.0.0/bits/stl_vector.h:65 7: note:
void std::vector<_Tp ,

//beginning

_Alloc>::insert (__gnu_cxx::__n ormal_iterator< typename _Alloc::pointer ,
std::vector<_Tp , _Alloc, size_t, const _Tp&) [with _Tp =
boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type>, _Alloc =
std::allocator< boost::tuples:: tuple<uint32_t, boost::shared_p tr<int>,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type,
boost::tuples:: null_type, boost::tuples:: null_type]

//end

shorter:
std::vector<... >::insert(std:: vector<...>::it erator, size_t, const
tuple<...>&)

Read the messages. They're long and hairy, but it's possible. Matching
parens is a good start.

--
rbh

[Roland Pibinger]

Re: Some problems with std::vector and nested templates

On Sun, 17 Jun 2007 15:22:52 -0000, jubelbrus wrote:

>I get the following error:
>list.h: In member function 'uint32_t
>stdtools::list <T>::insert(boo st::shared_ptr< T>) [with T = int]':
>tester_a.cpp:1 0: instantiated from here
>list.h:90: error: no matching function for call to
>'std::vector<b oost::tuples::t uple<uint32_t, boost::shared_p tr<int>,
>boost::tuples: :null_type, boost::tuples:: null_type,
>boost::tuples: :null_type, boost::tuples:: null_type,
>boost::tuples: :null_type, boost::tuples:: null_type,
>boost::tuples: :null_type, boost::tuples:: null_type>,

[snipped template jumble]

Why don't you ask Boost when you've got a Boost problem?

http://www.boost.org/more/mailing_lists.htm#users

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

[John Harrison]

Re: Some problems with std::vector and nested templates

>Perhaps you mean

>>
> m_vector.push_b ack( add_item );
>>
>There is no method of vector called insert that takes a single argument.
>>
>john

>
oh... :)
>
thanks
>

Those super long error messages make you think there must be something
really significant wrong with your code. But sometimes it's just the
obvious stuff.

john

[Roland Pibinger]

Re: Some problems with std::vector and nested templates

On Sun, 17 Jun 2007 16:00:40 GMT, John Harrison wrote:

>Those super long error messages make you think there must be something
>really significant wrong with your code. But sometimes it's just the
>obvious stuff.

Obviously, there is 'something really significant wrong' with Boost.


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

[Jerry Coffin]

Re: Some problems with std::vector and nested templates

In article <4675619b.23636 38@news.utanet. at>, rpbg123@yahoo.c om says...

On Sun, 17 Jun 2007 16:00:40 GMT, John Harrison wrote:

Those super long error messages make you think there must be something
really significant wrong with your code. But sometimes it's just the
obvious stuff.

>
Obviously, there is 'something really significant wrong' with Boost.

Hardly -- you can get the same sort of problems without using Boost. The
problem is sufficiently widespread that Leor Zolman has put quite a bit
of work into stlfilt, to try to make error messages more readable. As I
understand it, lousy error messages from templated code also provided
the motivation for the work that led to Concepts.

--
Later,
Jerry.

The universe is a figment of its own imagination.

[John Harrison]

Re: Some problems with std::vector and nested templates

Roland Pibinger wrote:

On Sun, 17 Jun 2007 16:00:40 GMT, John Harrison wrote:

>Those super long error messages make you think there must be something
>really significant wrong with your code. But sometimes it's just the
>obvious stuff.

>
Obviously, there is 'something really significant wrong' with Boost.
>
>

At least one compiler I know would quote typedefs that you use back to
you in error messages. So if the OP had written

typedef typename boost::tuple<ui nt32_t, boost::shared_p tr<T item_type;

he might have got a considerably shorter error message.

john

[Roland Pibinger]

Re: Some problems with std::vector and nested templates

On Sun, 17 Jun 2007 11:07:57 -0600, Jerry Coffin wrote:

>In article <4675619b.23636 38@news.utanet. at>, rpbg123@...com says...

>Obviously, there is 'something really significant wrong' with Boost.

>
>Hardly -- you can get the same sort of problems without using Boost.

Hardly. No one abuses templates the way Boost does.

>The
>problem is sufficiently widespread that Leor Zolman has put quite a bit
>of work into stlfilt, to try to make error messages more readable.

The treatment of symptoms is not a cure.

>As I
>understand it, lousy error messages from templated code also provided
>the motivation for the work that led to Concepts.

You mean Stroustrup's where-clause? OMG, please no!


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

[Thomas J. Gritzan]

Re: Some problems with std::vector and nested templates

Roland Pibinger wrote:

>As I
>understand it, lousy error messages from templated code also provided
>the motivation for the work that led to Concepts.

>
You mean Stroustrup's where-clause? OMG, please no!

What? Why not?

Do you like non-understandable error messages?

--
Thomas

http://www.netmeister.org/news/learn2quote.html

[Jerry Coffin]

Re: Some problems with std::vector and nested templates

In article <4675a1c3.10722 21@news.utanet. at>, rpbg123@yahoo.c om says...

On Sun, 17 Jun 2007 11:07:57 -0600, Jerry Coffin wrote:

In article <4675619b.23636 38@news.utanet. at>, rpbg123@...com says...

Obviously, there is 'something really significant wrong' with Boost.

Hardly -- you can get the same sort of problems without using Boost.

>
Hardly. No one abuses templates the way Boost does.

Actually, everybody else who wants to accomplish the same sorts of
things tends to write fairly similar code -- there are only so many ways
to skin a cat...

The
problem is sufficiently widespread that Leor Zolman has put quite a bit
of work into stlfilt, to try to make error messages more readable.

>
The treatment of symptoms is not a cure.

I didn't say it was a cure -- but note the "stl" in its name -- it's for
fixing messages that arise from the standard library, NOT Boost.

As I
understand it, lousy error messages from templated code also provided
the motivation for the work that led to Concepts.

>
You mean Stroustrup's where-clause? OMG, please no!

I mean Concepts. For the formal paper see:

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2193.pdf

If you care, you can find quite a bit more at:

http://conceptgcc.wordpress.com/

There will probably be at least a few more minor changes by the time the
standard is finalized, but most of it seems nearly certain to be in C++
0x.

--
Later,
Jerry.

The universe is a figment of its own imagination.