id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
7748,Allow explicit result_type specification for transformed,nathan.crookston+boost@…,Neil Groves,"Code like the following doesn't work trunk (and released) transformed:


{{{
std::vector<int> myList(...);
float sum = boost::accumulate(myList | transformed([](int a) { return a * 5; }), 0.f);
}}}


The following patch & test modifications allow the following syntax:

{{{
float sum = boost::accumulate(myList | transformed<float>([](int a) { return a * 5.f; }), 0.f);
}}}


This wouldn't be a problem if result_of used or fell back to decltype, but it seems that won't be available for a while.  The proposed syntax could also be helpful when using transformed with functors whose implementations are both unmodifiable and don't follow result_of.

Patch has been tested with VC10 and compiled with g++ 4.5 (with and without -std=c++0x) and clang++ (without c++0x).
",Feature Requests,closed,To Be Determined,range,Boost Development Trunk,Problem,invalid,,