Re: [Boost-users] [lambda] helping lambda to deduce return type and then avoid 'ret<T>'

Subject: Re: [Boost-users] [lambda] helping lambda to deduce return type and then avoid 'ret<T>'
From: OvermindDL1 (overminddl1_at_[hidden])
Date: 2010-05-24 20:05:33

On Mon, May 24, 2010 at 2:51 PM, Matthias Schabel
<boost_at_[hidden]> wrote:
>> and indeed for even very simple arithmetic user-defined classes (for
>> example boost.units quantities) the lambda expression is poluted with
>> many many ret<T> statements,
>> for example
>>
>> _1*_1/(_1+x)/(_1-x)
>>
>> becomes
>>
>> ret<anothertype>(ret<usertype>(_1*_1)/
>> ret<othertype>(ret<usertype>(_1+x)/ret<usertype>(_1-x)));
>>
>> the question is, is there a way to help lambda library to help
>> deducing the return type to avoid the repeated use of ret<T>.
>
> You should take a look at <boost/units/lambda.hpp> - Torsten Maehne contributed it to deal with interplay between lambda and units... Something similar might be worthwhile with interval as well.

Or Boost.Phoenix, it handles such things better.