Re: [Boost-users] [Proto] Storing an Expression Template as a Data Member

Subject: Re: [Boost-users] [Proto] Storing an Expression Template as a Data Member
From: Roman Perepelitsa (roman.perepelitsa_at_[hidden])
Date: 2011-01-06 11:56:57

2011/1/6 Roman Perepelitsa <roman.perepelitsa_at_[hidden]>

> 2011/1/6 Hossein Haeri <powerprogman_at_[hidden]>
>
>> Dear Eric,
>>
>> I will certainly have another read over make_expr. But, I have a feeling
>> that I might not have explained what I need very well. So, with some
>> connection to the function streaming thing we were in contact on previous
>> threads, here is an example:
>>
>> MyClass mc(_1 >> &f >> &g >> &h);
>> mc.set_input(-61.1);
>> cout << mc.value();//returns h(g(f(-61.1)))
>>
>> Now, are you telling me that I can store that "_1 >> &f >> &g >> &h" bit
>> in a data member of mc using make_expr? If so, what will the type of that
>> data member be? Or, are you suggesting a totally different design?
>
>
> This is not possible in C++.
>

I take it back :-) It *is* possible if the expression involves only
functions and no function objects.

Roman Perepelitsa.