headers: Drop LIBXMLPP_API from 'friend' members (#47)

fanc999-1 · web-flow · commit b8d403ffb8b4 · 2022-10-21T15:35:03.000+08:00
They aren't really necessary and can raise warnings on Windows MinGW
builds unless their locations were exchanged with 'class' or 'struct',
but doing so is not liked by Visual Studio.
diff --git a/libxml++/document.h b/libxml++/document.h
@@ -72,7 +72,7 @@ class Document : public NonCopyable
     ~Init() noexcept;
   };
 
-  friend LIBXMLPP_API class SaxParser;
+  friend class SaxParser;
 
 public:
   /** Create a new document.
diff --git a/libxml++/parsers/saxparser.h b/libxml++/parsers/saxparser.h
@@ -250,7 +250,7 @@ class SaxParser : public Parser
   // and never seen in the API:
   std::unique_ptr<Document> entity_resolver_doc_;
 
-  friend LIBXMLPP_API struct SaxParserCallback;
+  friend struct SaxParserCallback;
 };
 
 } // namespace xmlpp
diff --git a/libxml++/parsers/textreader.h b/libxml++/parsers/textreader.h
@@ -292,7 +292,7 @@ class TextReader: public NonCopyable
 
   private:
     class PropertyReader;
-    friend LIBXMLPP_API class PropertyReader;
+    friend class PropertyReader;
 
     LIBXMLPP_API
     void setup_exceptions();
