Rework config::{omitted,required,optional}() into unified config_lookup()

1 files changed, 62 insertions, 0 deletions

diff --git a/libbuild2/config/utility.ixx b/libbuild2/config/utility.ixx
new file mode 100644
index 0000000..79d5470
--- /dev/null
+++ b/libbuild2/config/utility.ixx
@@ -0,0 +1,62 @@
+// file      : libbuild2/config/utility.ixx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+namespace build2
+{
+  namespace config
+  {
+    LIBBUILD2_SYMEXPORT pair<lookup, bool>
+    lookup_config_impl (scope&, const variable&);
+
+    template <typename T>
+    pair<lookup, bool>
+    lookup_config_impl (scope&, const variable&, T&&, uint64_t, bool);
+
+    inline lookup
+    lookup_config (scope& rs, const variable& var)
+    {
+      return lookup_config_impl (rs, var).first;
+    }
+
+    inline lookup
+    lookup_config (bool& new_value, scope& rs, const variable& var)
+    {
+      auto r (lookup_config_impl (rs, var));
+      new_value = new_value || r.second;
+      return r.first;
+    }
+
+    template <typename T>
+    inline lookup
+    lookup_config (scope& rs,
+                   const variable& var,
+                   T&& def_val,
+                   uint64_t sflags,
+                   bool def_ovr)
+    {
+      return lookup_config_impl (rs,
+                                 var,
+                                 std::forward<T> (def_val), // VC14
+                                 sflags,
+                                 def_ovr).first;
+    }
+
+    template <typename T>
+    inline lookup
+    lookup_config (bool& new_value,
+                   scope& rs,
+                   const variable& var,
+                   T&& def_val,
+                   uint64_t sflags,
+                   bool def_ovr)
+    {
+      auto r (lookup_config_impl (rs,
+                                  var,
+                                  std::forward<T> (def_val), // VC14
+                                  sflags,
+                                  def_ovr));
+      new_value = new_value || r.second;
+      return r.first;
+    }
+  }
+}