Function signature as string

[John Chapman via Digitalmars-d-learn]

Is there any way to get a string representing a function's exact 
signature as declared in the source? I can generate it myself 
using reflection but it might not be 100% verbatim so wanted to 
know if there's anything built in?

  foreach (m; __traits(allMembers, T)) {
    alias member = __traits(getMember, T, m);
    string signature = // Call some function to get "member"'s 
signature as a string
  }