Change path::extension() to return std::string, not C string

The old behaviour (sometimes useful) is provided by extension_cstring().

2 files changed, 22 insertions, 5 deletions

diff --git a/butl/path b/butl/path
index 726bbe6..064c8aa 100644
--- a/butl/path
+++ b/butl/path
@@ -702,13 +702,19 @@ namespace butl
     basic_path
     base () const;
 
-    // Return the extension or NULL if not present. If not NULL, then
-    // the result points to the character past the dot but it is legal
-    // to decrement it once to obtain the value with the dot.
+    // Return the extension or NULL if not present. If not empty, then the
+    // result starts with the character past the dot.
     //
-    const C*
+    string_type
     extension () const;
 
+    // Return the in-place pointer to extension or NULL if not present. If not
+    // NULL, then the result points to the character past the dot but it is
+    // legal to decrement it once to obtain the value with the dot.
+    //
+    const C*
+    extension_cstring () const;
+
     // Return a path relative to the specified path that is equivalent
     // to *this. Throws invalid_path if a relative path cannot be derived
     // (e.g., paths are on different drives on Windows).
diff --git a/butl/path.ixx b/butl/path.ixx
index b1212f4..9705b66 100644
--- a/butl/path.ixx
+++ b/butl/path.ixx
@@ -304,11 +304,22 @@ namespace butl
   }
 
   template <typename C, typename K>
-  inline const C* basic_path<C, K>::
+  inline typename basic_path<C, K>::string_type basic_path<C, K>::
   extension () const
   {
     const string_type& s (this->path_);
     size_type p (traits::find_extension (s));
+    return p != string_type::npos
+      ? string_type (s.c_str () + p + 1)
+      : string_type ();
+  }
+
+  template <typename C, typename K>
+  inline const C* basic_path<C, K>::
+  extension_cstring () const
+  {
+    const string_type& s (this->path_);
+    size_type p (traits::find_extension (s));
     return p != string_type::npos ? s.c_str () + p + 1 : nullptr;
   }