Merge pull request #179 from herwinw/refactorings_link

Add link to E.12 on refactorings page

Author: codereport

learning/REFACTORINGS.md

@@ -1,11 +1,12 @@
 ## Refactorings
 
 ### Core Guidelines Used
+* [Con.4: Use const to define objects with values that do not change after construction](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#con4-use-const-to-define-objects-with-values-that-do-not-change-after-construction)
 * [ES.21: Don’t introduce a variable (or constant) before you need to use it](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines.html#es21-dont-introduce-a-variable-or-constant-before-you-need-to-use-it)
 * [ES.22: Don’t declare a variable until you have a value to initialize it with](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es22-dont-declare-a-variable-until-you-have-a-value-to-initialize-it-with)
 * [ES.30: Don’t use macros for program text manipulation](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es30-dont-use-macros-for-program-text-manipulation)
 * [ES.49: If you must use a cast, use a named cast](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es49-if-you-must-use-a-cast-use-a-named-cast)
-* [Con.4: Use const to define objects with values that do not change after construction](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#con4-use-const-to-define-objects-with-values-that-do-not-change-after-construction)
+* [E.12: Use noexcept when exiting a function because of a throw is impossible or unacceptable](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#e12-use-noexcept-when-exiting-a-function-because-of-a-throw-is-impossible-or-unacceptable)
 
 | Rule  |   Core Guideline   | Count |
 | :---: | :----------------: | :---: |