1 files changed, 45 insertions, 0 deletions
diff --git a/build2/config/utility.txx b/build2/config/utility.txx
new file mode 100644
index 0000000..c88a34f
--- /dev/null
+++ b/build2/config/utility.txx
@@ -0,0 +1,45 @@
+// file      : build2/config/utility.txx -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <build2/scope>
+
+namespace build2
+{
+  namespace config
+  {
+    template <typename T>
+    std::pair<std::reference_wrapper<const value>, bool>
+    required (scope& root, const variable& var, const T& def_value, bool ovr)
+    {
+      using result = std::pair<std::reference_wrapper<const value>, bool>;
+
+      if (auto l = root[var])
+      {
+        if (l.belongs (*global_scope))
+          return result (root.assign (var) = *l, true);
+
+        if (!ovr || l.belongs (root))
+          return result (*l, false);
+      }
+
+      return result (root.assign (var) = def_value, true);
+    }
+
+    template <typename T>
+    bool
+    find_option (const char* option, T& s, const char* var)
+    {
+      if (auto l = s[var])
+      {
+        for (const std::string& s: as<strings> (*l))
+        {
+          if (s == option)
+            return true;
+        }
+      }
+
+      return false;
+    }
+  }
+}