The <tr1/*>
headers should have been deprecated or removed following their inclusion in the standard. So they're mostly there for older compilers such as VS2010 or VS2008. Including <functional>
alone should fix it.
A couple things to note though, although I do not know if it applies to VS2013 is that std::regex
's include is <regex>
yet still resides in the old std::tr1
namespace.