Remove unused get_option

Fixes #121. Removes the unused `ParseResult::get_option`.

CHANGELOG.md

@@ -13,6 +13,7 @@ options. The project adheres to semantic versioning.
 
 * Fix a warning about possible loss of data.
 * Fix version numbering in CMakeLists.txt
+* Remove unused declaration of the undefined `ParseResult::get_option`.
 
 ## 2.1.1
 

include/cxxopts.hpp

@@ -1143,9 +1143,6 @@ namespace cxxopts
 
     private:
 
-    OptionValue&
-    get_option(std::shared_ptr<OptionDetails>);
-
     void
     parse(int& argc, char**& argv);