[boost] [config] config_test fails on g++ 4.8/4.9

Subject: [boost] [config] config_test fails on g++ 4.8/4.9
From: Peter Dimov (lists_at_[hidden])
Date: 2014-06-07 20:04:02

... due to

In file included from ../libs/config/test/config_test.cpp:376:0:
../libs/config/test/boost_no_lambdas.ipp: In function ???int 
boost_no_cxx11_lambdas::test()???:
../libs/config/test/boost_no_lambdas.ipp:21:4: error: expected 
primary-expression before ???void???
   (void)[](){};
    ^
../libs/config/test/boost_no_lambdas.ipp:21:4: error: expected ???)??? 
before ???void???

I'm not sure why.