More conversion fixes for gcc
diff --git a/include/json/writer.h b/include/json/writer.h
index 180ab68..49b1512 100644
--- a/include/json/writer.h
+++ b/include/json/writer.h
@@ -302,7 +302,7 @@
   ChildValues childValues_;
   std::ostream* document_;
   std::string indentString_;
-  int rightMargin_;
+  unsigned int rightMargin_;
   std::string indentation_;
   bool addChildValues_ : 1;
   bool indented_ : 1;
diff --git a/src/lib_json/json_writer.cpp b/src/lib_json/json_writer.cpp
index f7ceedc..f1f4dcc 100644
--- a/src/lib_json/json_writer.cpp
+++ b/src/lib_json/json_writer.cpp
@@ -524,7 +524,7 @@
         isMultiLine = true;
       }
       writeValue(value[index]);
-      lineLength += childValues_[index].length();
+      lineLength += static_cast<ArrayIndex>(childValues_[index].length());
     }
     addChildValues_ = false;
     isMultiLine = isMultiLine || lineLength >= rightMargin_;
@@ -743,7 +743,7 @@
         isMultiLine = true;
       }
       writeValue(value[index]);
-      lineLength += childValues_[index].length();
+      lineLength += static_cast<ArrayIndex>(childValues_[index].length());
     }
     addChildValues_ = false;
     isMultiLine = isMultiLine || lineLength >= rightMargin_;
@@ -1026,7 +1026,7 @@
         isMultiLine = true;
       }
       writeValue(value[index]);
-      lineLength += childValues_[index].length();
+      lineLength += static_cast<ArrayIndex>(childValues_[index].length());
     }
     addChildValues_ = false;
     isMultiLine = isMultiLine || lineLength >= rightMargin_;