Update README.md

Author: VioletGiraffe

parameter_pack/README.md

@@ -9,7 +9,7 @@
 * `template <size_t index, typename... Args> constexpr auto value_by_index(Args&&... args) noexcept` returns the *value* at position `index` from `args`.
 
 * `template <typename Functor, class... Args> void apply(Functor&& f, Args&&... args)` iterates the pack `args` and calls functor `f` with each *value* in the pack.
-<br>Example: `apply([](auto&& item){std::cout << value << std::endl;}, 0, -1.0f, "text");`
+<br>Example: `apply([](auto&& value){std::cout << value << std::endl;}, 0, -1.0f, "text");`
 
 * `template <typename... Args, typename Functor> void for_type(Functor&& f)` calls functor `f` for each *type* in the argument pack. The type is passed using `type_wrapper` helper template defined in `utils/template_magic.hpp`. 
 <br>Example: `for_type<int, float, std::string> ([](auto&& t){ using Type = typename decltype(t)::type; });`