14 Dec
2013
14 Dec
'13
9:06 p.m.
The compelling reason is that if it remains in the global namespace no other use of '_n' can be conveniently hoisted into the current scope at the same time via a 'using namespace xxx'. Whereas if it is in its own namespace, as in retrospect it should have been, then the flexibility of hoisting the use of '_n' from whatever library, can be preserved.
+1 As a frequent Boost.Phoenix user (and one who dislikes their 'argN' alternative), I run into this often. Regards, Nate