/// it returns an llvm::Error, i.e. there is a conflict between R and the
/// existing replacements (i.e. they are order-dependent) or R's file path is
/// different from the filepath of existing replacements. Callers must
- /// explicitly check the Error returned. This prevents users from adding
- /// order-dependent replacements. To control the order in which
+ /// explicitly check the Error returned, and the returned error can be
+ /// converted to a string message with `llvm::toString()`. This prevents users
+ /// from adding order-dependent replacements. To control the order in which
/// order-dependent replacements are applied, use merge({R}) with R referring
/// to the changed code after applying all existing replacements.
/// Two replacements A and B are considered order-independent if applying them