I have been wondering about the following concerning the spaces $\mathcal D$ of test functions (say on $\mathbf R$).
It is my understanding that the topology on this space is inductive limit topology. Are there other useful functions spaces like this (i.e. not contrived) whose topology is an inductive limit?
I also know that $\mathcal D$ is not metrizable. Is it first countable? Are they completely regular? Is there a reference with an outline of all the topological properties of these spaces?
Is there a way to define a uniformity on $\mathcal D$ to make them into a uniform space such that the topology it induces coincides with its inductive limit topology?