[Boost-bugs] [Boost C++ Libraries] #6590: BOOST_AUTO fails on C++11 lambdas

Subject: [Boost-bugs] [Boost C++ Libraries] #6590: BOOST_AUTO fails on C++11 lambdas
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-02-21 22:46:09

#6590: BOOST_AUTO fails on C++11 lambdas
----------------------------------------------+-----------------------------
 Reporter:  Anders Kaseorg <andersk@…>        |       Owner:  burbelgruff
     Type:  Feature Requests                  |      Status:  new        
Milestone:  To Be Determined                  |   Component:  typeof     
  Version:  Boost 1.48.0                      |    Severity:  Problem    
 Keywords:                                    |  
----------------------------------------------+-----------------------------
 `BOOST_AUTO` fails on C++11 lambdas as follows (tested with g++
 4.6.2-14ubuntu2):
 {{{
 #!C++
 #include <boost/typeof/typeof.hpp>
 BOOST_AUTO(f, [](){});
 }}}
 {{{
 $ g++ -c -std=c++0x test.cc
 test.cc:2:1: error: lambda-expression in unevaluated context
 test.cc:2:1: error: conversion from ‘<lambda()>’ to non-scalar type
 ‘<lambda()>’ requested
 }}}

 Although it’s apparently not possible to use `typeof` or `decltype` on a
 lambda expression, this could be fixed by defining `BOOST_AUTO` with C++11
 `auto` on compilers that support it:
 {{{
 #!C++
 #define BOOST_AUTO(Var, Expr) auto Var = Expr
 BOOST_AUTO(f, [](){});
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6590>
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