Some problems with std::vector and nested templates

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<boost::tuple<uint32_t, boost::shared_ptr<T >
m_vector;

template <class Tboost::shared_ptr<Tlist::<T>getitem(uint32_t id)
{
boost::mutex::scoped_lock lock(m_lock);

std::vector< boost::tuple<uint32_t, boost::shared_ptr<Tfind_if(m_vector.begin(), m_vector.end(), compare_list<T>(id),
m_vector.begin());

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

return boost::shared_ptr(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.

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

jubelbrus wrote:
I'm assuming uint32_t might be typedefed somewhere.
What's T? This is not a template?
huh?
template <class T>
boost::shared_ptr<T>
list<T>::getitem(uint32_t id)
?
What's list?
typename std::vector<boost::tuple<uint32_t, boost::shared_ptr<TYou need typename here, because vector< ... is dependent on T.
*pos is a tuple, not a shared_ptr
--
rbh

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_ptr<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<boost::tuple<uint32_t, boost::shared_ptr<T >
m_vector;

uint32_t m_nextid;

uint32_t insert(boost::shared_ptr<T>);
}

template <class T>
uint32_t list<T>::insert(boost::shared_ptr<T>)
{
typename boost::tuples::tuple<uint32_t, boost::shared_ptr<T
add_item(m_nextid, item);
typename std::vector<boost::tuple<uint32_t, boost::shared_ptr<Tboost::mutex::scoped_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(boost::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<boost::tuples::tuple<uint32_t, boost::shared_ptr<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_ptr<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_typeboost::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>::iterator std::vector<_Tp,
_Alloc>::insert(__gnu_cxx::__normal_iterator<typen ame _Alloc::pointer,
std::vector<_Tp, _Alloc, const _Tp&) [with _Tp =
boost::tuples::tuple<uint32_t, boost::shared_ptr<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_ptr<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:657: note:
void std::vector<_Tp,
_Alloc>::insert(__gnu_cxx::__normal_iterator<typen ame _Alloc::pointer,
std::vector<_Tp, _Alloc, size_t, const _Tp&) [with _Tp =
boost::tuples::tuple<uint32_t, boost::shared_ptr<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_ptr<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??

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

jubelbrus wrote:Perhaps you mean

m_vector.push_back( add_item );

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

john

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

On 17 Jun, 17:49, John Harrison <john_androni...@hotmail.comwrote:oh... :)

thanks

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

jubelbrus wrote:
There should be no typename here.
nor here.

typename are needed in:
T::something
or
someclass<T>::something
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>::something * 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>();
}
// beginning
//end

Shorter:
std::vector<...>::insert(tuple<...>)
//beginning
//end
shorter:
std::vector<...>::insert(std::vector<...>::iterato r, const tuple<...>&)
//beginning
//end

shorter:
std::vector<...>::insert(std::vector<...>::iterato r, size_t, const
tuple<...>&)

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

--
rbh

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

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

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

>Perhaps you meanThose 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

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

On Sun, 17 Jun 2007 16:00:40 GMT, John Harrison wrote:Obviously, there is 'something really significant wrong' with Boost.


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

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

In article <4675619b.2363638@news.utanet.at>, rpbg123@yahoo.com says...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.

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

Roland Pibinger wrote: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<uint32_t, boost::shared_ptr<T item_type;

he might have got a considerably shorter error message.

john

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

On Sun, 17 Jun 2007 11:07:57 -0600, Jerry Coffin wrote:Hardly. No one abuses templates the way Boost does.
The treatment of symptoms is not a cure.
You mean Stroustrup's where-clause? OMG, please no!


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

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

Roland Pibinger wrote:What? Why not?

Do you like non-understandable error messages?

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

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

In article <4675a1c3.1072221@news.utanet.at>, rpbg123@yahoo.com says...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...
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.
I mean Concepts. For the formal paper see:

http://www.open-std.org/jtc1/sc22/wg...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.