Issue 6973 - static assert(isOutputRange!(OutputRange!int, int)) is false

[9rnsr]

http://d.puremagic.com/issues/show_bug.cgi?id=6973

Allow union and interface types as a parameter of hasMember template.

[shoo]

I examined various methods, but think that this method is the passable.
However, this method is different from __traits(hasMember, T, name) in behavior in the details. Do you have any opinion?

[9rnsr]

E.g. __traits(hasMember, T, name) returns true if T == int[] and name == "put" (with std.array module), but it seems not to be expected behavior.
So hasMember template should restrict its parameter IMO, it is a design.