Question on boost lambda

[anton.bredikhin@gmail.com]

Hello everybody.

I want to write an unnamed predicate for std::find_if in-place.
If the vector is filled by raw struct, then I can find the target
element like that:


struct C
{
int i;
float f;
}

int main()
{
std::vector<Cv;
// somehow init v

std::find_if(v. begin(), v.end(), &_1->*&C::i == 3);
}


But I cannot make that to work if vector contains boost::shared_p tr to
the C struct.
std::vector<boo st::shared_ptr< C v;
// somehow init v

std::find_if(v. begin(), v.end(), ???);

Can anyone tell me how can I achieve that?

Thanks
std::find_if(v. begin(), v.end(), /*v->i==3*/ ??)

If the vector is filled by structs without shared_ptr, then I can find
an element like that:

std::find_if(v. begin(), v.end(), &_1->*&C::i == 3);

But I cannot make that code to work with pointers.

Thanks

[Kai-Uwe Bux]

Re: Question on boost lambda

anton.bredikhin @gmail.com wrote:

Hello everybody.
>
I want to write an unnamed predicate for std::find_if in-place.
If the vector is filled by raw struct, then I can find the target
element like that:
>
>
struct C
{
int i;
float f;
}
>
int main()
{
std::vector<Cv;
// somehow init v
>
std::find_if(v. begin(), v.end(), &_1->*&C::i == 3);
}
>
>
But I cannot make that to work if vector contains boost::shared_p tr to
the C struct.
std::vector<boo st::shared_ptr< C v;
// somehow init v
>
std::find_if(v. begin(), v.end(), ???);

[snip]

Try: &*_1->*&C::i == 3


Best

Kai-Uwe Bux

[anton.bredikhin@gmail.com]

Re: Question on boost lambda

Try:  &*_1->*&C::i == 3

>
Best
>
Kai-Uwe Bux

It works!
Thanks a lot!