1 files changed, 97 insertions, 0 deletions
diff --git a/build2/target-type b/build2/target-type
new file mode 100644
index 0000000..52a45f4
--- /dev/null
+++ b/build2/target-type
@@ -0,0 +1,97 @@
+// file      : build2/target-type -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BUILD2_TARGET_TYPE
+#define BUILD2_TARGET_TYPE
+
+#include <map>
+#include <string>
+#include <ostream>
+
+#include <build2/types>
+
+namespace build2
+{
+  class scope;
+  class target;
+  class target_key;
+  class prerequisite_key;
+
+  // Target type.
+  //
+  // Note that we assume there is always a single instance of this class
+  // for any target type. As a result, we can use address comparison to
+  // determine if two target types are the same.
+  //
+  //
+  struct target_type
+  {
+    const char* name;
+    const target_type* base;
+    target* (*factory) (const target_type&, dir_path, string, const string*);
+    const string& (*extension) (const target_key&, scope&);
+    target* (*search) (const prerequisite_key&);
+    bool see_through; // A group with the default "see through" semantics.
+
+    bool
+    is_a (const target_type&) const; // Defined in target.cxx
+
+    template <typename T>
+    bool
+    is_a () const {return is_a (T::static_type);}
+  };
+
+  inline bool
+  operator< (const target_type& x, const target_type& y) {return &x < &y;}
+
+  inline bool
+  operator== (const target_type& x, const target_type& y) {return &x == &y;}
+
+  inline bool
+  operator!= (const target_type& x, const target_type& y) {return &x != &y;}
+
+  inline std::ostream&
+  operator<< (std::ostream& os, const target_type& tt) {return os << tt.name;}
+
+  // Target type map.
+  //
+  struct target_type_ref
+  {
+    // Like reference_wrapper except it sometimes deletes the target type.
+    //
+    explicit
+    target_type_ref (const target_type& r): p_ (&r), d_ (false) {}
+
+    explicit
+    target_type_ref (unique_ptr<target_type>&& p)
+        : p_ (p.release ()), d_ (true) {}
+
+    target_type_ref (target_type_ref&& r)
+        : p_ (r.p_), d_ (r.d_) {r.p_ = nullptr;}
+
+    ~target_type_ref () {if (p_ != nullptr && d_) delete p_;}
+
+    explicit operator const target_type& () const {return *p_;}
+    const target_type& get () const {return *p_;}
+
+  private:
+    const target_type* p_;
+    bool d_;
+  };
+
+  using target_type_map_base = std::map<string, target_type_ref>;
+
+  class target_type_map: public target_type_map_base
+  {
+  public:
+    void
+    insert (const target_type& tt) {emplace (tt.name, target_type_ref (tt));}
+
+    template <typename T>
+    void
+    insert () {insert (T::static_type);}
+  };
+}
+
+#endif // BUILD2_TARGET_TYPE