Definintion of proto::context::null_context<>, an evaluation context for proto::eval() that simply evaluates each child expression, doesn't combine the results at all, and returns void. void void Expr & Context & For N in [0,Expr arity), evaluate: proto::eval(proto::child_c<N>(expr), context) An evaluation context for proto::eval() that simply evaluates each child expression, doesn't combine the results at all, and returns void. proto::context::null_eval< Expr, ThisContext >