Implement path_cast(), path::simple()

2 files changed, 52 insertions, 0 deletions

diff --git a/butl/path b/butl/path
index af01d05..5462cc9 100644
--- a/butl/path
+++ b/butl/path
@@ -145,6 +145,12 @@ namespace butl
   template <typename C, typename K>
   class basic_path;
 
+  // Cast from one path kind to another without any checking or
+  // processing.
+  //
+  template <class P, class C, class K> P path_cast (const basic_path<C, K>&);
+  template <class P, class C, class K> P path_cast (basic_path<C, K>&&);
+
   template <typename C>
   class path_data;
 
@@ -278,6 +284,13 @@ namespace butl
       return this->path_.empty ();
     }
 
+    // Return true if this path doesn't have any directories. Note
+    // that "/foo" is not a simple path (it is "foo" in root directory)
+    // while "/" is (it is the root directory).
+    //
+    bool
+    simple () const;
+
     bool
     absolute () const;
 
@@ -497,6 +510,18 @@ namespace butl
     posix_string () const;
 
   private:
+    template <class P, class C1, class K1>
+    friend P butl::path_cast (const basic_path<C1, K1>&);
+
+    template <class P, class C1, class K1>
+    friend P butl::path_cast (basic_path<C1, K1>&&);
+
+    basic_path (string_type s, bool i): base_type (std::move (s))
+    {
+      if (i)
+        init ();
+    }
+
     void
     init ();
   };
diff --git a/butl/path.ixx b/butl/path.ixx
index 0cbbeaf..3e8a9cc 100644
--- a/butl/path.ixx
+++ b/butl/path.ixx
@@ -25,6 +25,33 @@ namespace butl
   }
 #endif
 
+  // @@ Should only enable_if P is basic_path<C, K1>.
+  //
+  template <class P, class C, class K>
+  inline P
+  path_cast (const basic_path<C, K>& p)
+  {
+    return P (p.path_, false);
+  }
+
+  template <class P, class C, class K>
+  inline P
+  path_cast (basic_path<C, K>&& p)
+  {
+    return P (std::move (p.path_), false);
+  }
+
+  template <typename C, typename K>
+  inline bool basic_path<C, K>::
+  simple () const
+  {
+    return
+#ifndef _WIN32
+      root () ||
+#endif
+      traits::find_separator (this->path_) == string_type::npos;
+  }
+
   template <typename C, typename K>
   inline bool basic_path<C, K>::
   absolute () const