I'd like to be able to write things like

a = b + f(c)

where
a is a vector (or matrix)
b, c are vector (or matrix) expressions
f is a function to be applied to every element in c

What do I need to do in order to get my function application behave as an ublas (vector or matrix) expression?

The objective is to integrate it into the expression template of ublas in order to avoid temporaries.

TIA