Re: [Boost-users] [mpl][type_traits] Transforming to common type

AMDG On 02/22/2014 05:25 AM, Bjorn Reese wrote:

<snip> /usr/local/include/boost/type_traits/common_type.hpp:111:42: error: incompatible operand types ('mpl_::arg<1>' and 'int') typedef decltype(declval<bool>() ? declval<T>() : declval<U>()) type; ^ ~~~~~~~~~~~~ ~~~~~~~~~~~~

It appears that the placeholder is not expanded to its actual type.

Don't use ::type in MPL Lambda expressions. It forces immediate evaluation, which is not what you want.

<snip> boost::common_type<boost::mpl::_1, int>::type <snip>

In Christ, Steven Watanabe