Update return types for Plugin's Name and Filename (#1055)

Signed-off-by: Nate Koenig <[email protected]>

Co-authored-by: Nate Koenig <[email protected]>

include/sdf/Plugin.hh

@@ -80,7 +80,7 @@ namespace sdf
  /// The name of the plugin should be unique within the scope of its
  /// parent.
  /// \return Name of the plugin.
- public: std::string Name() const;
+ public: const std::string &Name() const;
 
  /// \brief Set the name of the plugin.
  /// The name of the plugin should be unique within the scope of its
@@ -90,7 +90,7 @@ namespace sdf
 
  /// \brief Get the filename of the shared library.
  /// \return Filename of the shared library associated with the plugin.
- public: std::string Filename() const;
+ public: const std::string &Filename() const;
 
  /// \brief Remove the contents of the plugin, this is everything that
  /// is a child element of the `<plugin>`.

src/Plugin.cc

@@ -125,7 +125,7 @@ Errors Plugin::Load(ElementPtr _sdf)
 }
 
 /////////////////////////////////////////////////
-std::string Plugin::Name() const
+const std::string &Plugin::Name() const
 {
  return this->dataPtr->name;
 }
@@ -137,7 +137,7 @@ void Plugin::SetName(const std::string &_name)
 }
 
 /////////////////////////////////////////////////
-std::string Plugin::Filename() const
+const std::string &Plugin::Filename() const
 {
  return this->dataPtr->filename;
 }