[boost] Constructor with parameters -- Lambda

From: albert meyburgh (ameyburgh_at_[hidden])
Date: 2008-06-16 12:55:03

Thanks for the input on trying to use boost::lambda::bind instead of
boost::bind, unfortunately there is no bind in the lambda namespace.

I'm using Boost 1.35, and in my version "namespace lambda" only exists in
boost\lambda\construct.hpp and only contains a single templated struct
constructor, there is no bind available :(

Any ideas?

I'm trying all sort of funny syntax variations to no avail...

Message: 4
Date: Fri, 13 Jun 2008 15:37:58 -0700
From: "albert meyburgh" <ameyburgh_at_[hidden]>
Subject: [boost] Constructor with parameters -- Lambda
To: boost_at_[hidden]
Message-ID:
       <35f053b10806131537o4b85769fg84a88bc0c70dddc4_at_[hidden]>
Content-Type: text/plain; charset=ISO-8859-1

Hi,

I'm trying to use the lambda constructor provided in boost and it's not
compiling.

class someclass
{
someclass(sometype, int x)
}

std::vector v<sometype>
std::vector v2<someclass>
std::transform( v.begin(),
                   v.end(),
                   std::back_inserter( v2 ),
                   boost::bind( boost::lambda::constructor<someclass>(),
_1, 5) ); // where 5 is a constant int parameter for x to the constructor

Resulting in

Error    1    error C2039: 'result_type' : is not a member of
'boost::lambda::constructor<T>'   boost_1_35_0\boost\bind.hpp    67
Error    2    error C2146: syntax error : missing ';' before identifier
'type'    boost_1_35_0\boost\bind.hpp    67
Error    3    error C4430: missing type specifier - int assumed. Note: C++
does not support default-int    boost_1_35_0\boost\bind.hpp    67
Error    4    error C2208: 'boost::_bi::type' : no members defined using
this type   boost_1_35_0\boost\bind.hpp    67
Error    5    fatal error C1903: unable to recover from previous error(s);
stopping compilation    boost_1_35_0\boost\bind.hpp    67

What is wrong with my syntax?

------------------------------

Message: 5
Date: Fri, 13 Jun 2008 15:57:59 -0700
From: Steven Watanabe <watanabesj_at_[hidden]>
Subject: Re: [boost] Constructor with parameters -- Lambda
To: boost_at_[hidden]
Message-ID: <4852FB77.4000902_at_[hidden]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

AMDG

albert meyburgh wrote:
>                     boost::bind( boost::lambda::constructor<someclass>(),
> _1, 5) ); // where 5 is a constant int parameter for x to the constructor
>

Use boost::lambda::bind.

In Christ,
Steven Watanabe

------------------------------

Message: 6
Date: Fri, 13 Jun 2008 15:59:14 -0700
From: Eric Niebler <eric_at_[hidden]>
Subject: Re: [boost] Constructor with parameters -- Lambda
To: boost_at_[hidden]
Message-ID: <4852FBC2.8040606_at_[hidden]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

albert meyburgh wrote:
> Hi,
>
> I'm trying to use the lambda constructor provided in boost and it's not
> compiling.
>
> class someclass
> {
> someclass(sometype, int x)
> }
>
> std::vector v<sometype>
> std::vector v2<someclass>
> std::transform( v.begin(),
>                     v.end(),
>                     std::back_inserter( v2 ),
>                     boost::bind( boost::lambda::constructor<someclass>(),

Try boost::lambda::bind() instead of boost::bind().

--
Eric Niebler
BoostPro Computing
http://www.boostpro.com