Implement automatic subproject discovery

Currently we only capture their directories without the project
names. We will need project names when we hook import search into
this.

1 files changed, 8 insertions, 0 deletions

diff --git a/build/variable b/build/variable
index 064a10a..9c6d3bc 100644
--- a/build/variable
+++ b/build/variable
@@ -189,10 +189,18 @@ namespace build
   as<const list_value&> () const {return as<list_value&> ();}
 
   template <>
+  std::string& value_proxy::
+  as<std::string&> () const;
+
+  template <>
   const std::string& value_proxy::
   as<const std::string&> () const;
 
   template <>
+  dir_path& value_proxy::
+  as<dir_path&> () const;
+
+  template <>
   const dir_path& value_proxy::
   as<const dir_path&> () const;
 }