[Boost-users] RV: assign shared_ptr to 0 in initialization list

13 Sep 2006

      Hi,

I've been following this thread  and been unable to do the same with:

boost::shared_ptr< map > ()

So I can't do:

constructor ( boost::shared_ptr< map > varName =
boost::shared_ptr< map > () )

The error I get is (why/how do I specify the missing params for map?):

       [cc] /home/bereng/blaseek/src/lib/cppToolkit/DBHelper.h:61: error:
expected a,a or a...a before a>a token
       [cc] /home/bereng/blaseek/src/lib/cppToolkit/DBHelper.h:61: error:
wrong number of template arguments (1, should be 4)
       [cc]
/usr/lib/gcc/i386-redhat-linux/4.1.1/../../../../include/c++/4.1.1/bits/stl_
map.h:92: error: provided for atemplate class std::mapa
       [cc] /home/bereng/blaseek/src/lib/cppToolkit/DBHelper.h:61: error:
template argument 1 is invalid
       [cc] /home/bereng/blaseek/src/lib/cppToolkit/DBHelper.h:61: error:
default argument missing for parameter 2 of
aboost::shared_ptrcppToolkit::ResultSet
cppToolkit::DBHelper::findObject(boost::shared_ptr,
std::basic_string,
std::less >, std::allocator,
std::basic_string > > >
...
, std::string)a
Thanks a lot in advance.

-----Mensaje original-----
De: boost-users-bounces@lists.boost.org
[mailto:boost-users-bounces@lists.boost.org]En nombre de Scott Amort
Enviado el: lunes, 14 de agosto de 2006 1:09
Para: boost-users@lists.boost.org
Asunto: Re: [Boost-users] assign shared_ptr to 0 in initialization list

Hi Scott,

Thanks for the quick reply!

On Sun, 2006-08-13 at 18:11 -0400, me22 wrote:
...
Instead of
...
if (writer_.get() == 0) { /* create default error writer */ }
Why not just use
if ( !writer_ ) { /* create default error writer */ }
instead?  This would work with ordinary pointers too.
Thanks, that is clearer!
...
...
What is the equivalent to:
Parser testParser(0);
Parser testParser( ErrorWriterPtr() ); // would work
I'd be tempted instead to replace the constructor definition with
Parser(ErrorWriterPtr writer = ErrorWritePtr())
  : writer_(writer)
  {
  }
however, to be able to just say
Parser testParser;
if you don't want to specify the writer.
Perfect!  Thanks again.

Best,
Scott

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[Boost-users] RV: assign shared_ptr to 0 in initialization list

Berenguer Blasi