We currently have \indexlibrary (just add an index entry; full LaTeX syntax support) and \indexlibrarymember{a}{b} which adds entries for a!b and b!a. The latter automatically wraps the arguments in \idxcode. The former doesn't, such that nearly all uses of (plain) \indexlibrary (except those creating entries for constructors and destructors) have a nested \idxcode. That's both error-prone and too verbose.
Suggestion: Add macro \indexlibraryitem{a} which automatically adds the \idxcode. Add macro \indexlibraryspmember{a}{b} ("special member function") which does not wrap "a" into \idxcode, but otherwise behaves like \indexlibrarymember. End result: grep -w indexlibrary should only show hits in macros.tex going forward.