From 6535bf6175af32e2514faf75d2742424751a783b Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Wed, 15 Apr 2015 14:10:50 +0200
Subject: New variables architecture

Now operator[] is only used for lookup.
---
 build/target.cxx | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

(limited to 'build/target.cxx')

diff --git a/build/target.cxx b/build/target.cxx
index fbba1ed..5be0a8d 100644
--- a/build/target.cxx
+++ b/build/target.cxx
@@ -52,15 +52,32 @@ namespace build
   }
 
   value_proxy target::
-  operator[] (const variable& var)
+  operator[] (const variable& var) const
   {
-    auto i (variables.find (var));
+    auto i (vars.find (var));
 
-    return i != variables.end ()
-      ? value_proxy (&i->second, nullptr)
+    return i != vars.end ()
+      // @@ Same issue as in variable_map: need ro_value_proxy.
+      ? value_proxy (&const_cast<value_ptr&> (i->second), &vars)
       : base_scope ()[var];
   }
 
+  value_proxy target::
+  append (const variable& var)
+  {
+    value_proxy val (operator[] (var));
+
+    if (val && val.belongs (*this)) // Existing variable in this target.
+      return val;
+
+    value_proxy r (assign (var));
+
+    if (val)
+      r = val; // Copy value from the outer scope.
+
+    return r;
+  }
+
   ostream&
   operator<< (ostream& os, const target& t)
   {
-- 
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