Add ability to depend on (declared) ad hoc group member

1 files changed, 12 insertions, 8 deletions

diff --git a/build2/target.hxx b/build2/target.hxx
index e167211..4c0efbe 100644
--- a/build2/target.hxx
+++ b/build2/target.hxx
@@ -1539,14 +1539,18 @@ namespace build2
     // any time but any subsequent updates must set the same path. Or, in
     // other words, once the path is set, it never changes.
     //
-    // A set empty path may signify special unknown/undetermined/unreal
-    // location (for example, a binless library or an installed import library
-    // -- we know the DLL is there, just not exactly where). In this case you
-    // would also normally set its mtime. We used to return a pointer to
-    // properly distinguish between not set and empty but that proved too
-    // tedious. Note that this means there could be a race between path and
-    // mtime (unless you lock the target in some other way; see file_rule) so
-    // for this case it makes sense to set the timestamp first.
+    // An empty path may signify special unknown/undetermined/unreal location
+    // (for example, a binless library or an installed import library -- we
+    // know the DLL is there, just not exactly where). In this case you would
+    // also normally set its mtime.
+    //
+    // We used to return a pointer to properly distinguish between not set and
+    // empty but that proved too tedious to work with. So now we return empty
+    // path both when not set (which will be empty_path so you can distinguish
+    // the two case if you really want to) and when set to empty. Note that
+    // this means there could be a race between path and mtime (unless you
+    // lock the target in some other way; see file_rule) so in this case it
+    // makes sense to set the timestamp first.
     //
     const path_type&
     path () const;