Re: [Boost-users] Using lambda expressions in stl algorithms

Subject: Re: [Boost-users] Using lambda expressions in stl algorithms
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2010-12-14 10:21:10

AMDG

On 12/14/2010 6:49 AM, przemyslaw.sliwa_at_[hidden] wrote:
> Could someone tell me why this code does not compile? Can it be modified
> in order to compile?
>
>          struct CcyCplEventKey
>          {
>                  CurrencyCouple  CcyCpl;
>                  EventType               Event;
>          }
>
>          typedef std::map<CurrencyEventKey, CurrencyEventPtr>  mapType;
>
>          mapType ccyOut;
>
>          std::for_each(ccyOut.begin(), ccyOut.end(),
> (&*boost::lambda::_1)->*&CcyCplEventKey::Event);

boost::lambda::_1 gets replaced with an object of type
std::pair<const CurrencyEventKey, CurrencyEventPtr>.

a) std::pair can't be dereferenced.
b) Even if it could be, you can't call a member function of CcyCplEventKey
     with a std::pair.
c) Accessing a data member has no side-effects.  The
     for_each doesn't do anything, so I don't know what
     you're trying to accomplish.

In Christ,
Steven Watanabe