Initial support for amalgamation/subprojects

For now both need to be manually specified in src bootstrap. At
this stage main() loads any outer root scopes while include loads
any inner.

1 files changed, 17 insertions, 0 deletions

diff --git a/build/variable b/build/variable
index 500cc00..aca0bed 100644
--- a/build/variable
+++ b/build/variable
@@ -240,6 +240,23 @@ namespace build
       return value_proxy (&base::operator[] (v), &scope_);
     }
 
+    value_proxy
+    operator[] (const std::string& v) const
+    {
+      return operator[] (variable_pool.find (v));
+    }
+
+    value_proxy
+    operator[] (const variable& v) const
+    {
+      auto i (find (v));
+      return i != end ()
+        // @@ To do this properly we seem to need ro_value_proxy.
+        //
+        ? value_proxy (&const_cast<value_ptr&> (i->second), &scope_)
+        : value_proxy (nullptr, nullptr);
+    }
+
     std::pair<iterator, iterator>
     find_namespace (const std::string& ns)
     {