Simplify swizzling implementation into one swizzle class

glm/core/type_vec2.hpp

@@ -115,17 +115,7 @@ namespace detail
 		tvec2(tref2<T> const & r);
 
         template <int E0, int E1>
-        GLM_FUNC_DECL tvec2(glm::detail::swizzle2<T,tvec2<T>,E0,E1>& that)
-        {
-            *this = that();
-        }
-        template <int E0, int E1>
-        GLM_FUNC_DECL tvec2(glm::detail::swizzle3_2<T,tvec2<T>,E0,E1>& that)
-        {
-            *this = that();
-        }
-        template <int E0, int E1>
-        GLM_FUNC_DECL tvec2(glm::detail::swizzle4_2<T,tvec2<T>,E0,E1>& that)
+        GLM_FUNC_DECL tvec2(const glm::detail::swizzle<2,T,tvec2<T>,E0,E1,-1,-2>& that)
         {
             *this = that();
         }

glm/core/type_vec3.hpp

@@ -117,17 +117,7 @@ namespace detail
 		GLM_FUNC_DECL tvec3(tref3<T> const & r);
 
         template <int E0, int E1, int E2>
-        GLM_FUNC_DECL tvec3(glm::detail::swizzle2_3<T,tvec3<T>,E0,E1,E2>& that)
-        {
-            *this = that();
-        }
-        template <int E0, int E1, int E2>
-        GLM_FUNC_DECL tvec3(glm::detail::swizzle3<T,tvec3<T>,E0,E1,E2>& that)
-        {
-            *this = that();
-        }
-        template <int E0, int E1, int E2>
-        GLM_FUNC_DECL tvec3(glm::detail::swizzle4_3<T,tvec3<T>,E0,E1,E2>& that)
+        GLM_FUNC_DECL tvec3(const glm::detail::swizzle<3,T,tvec3<T>,E0,E1,E2,-1>& that)
         {
             *this = that();
         }

glm/core/type_vec4.hpp

@@ -119,17 +119,7 @@ namespace detail
 		GLM_FUNC_DECL tvec4(tref4<T> const & r);
 
         template <int E0, int E1, int E2, int E3>
-        GLM_FUNC_DECL tvec4(glm::detail::swizzle2_4<T,tvec4<T>,E0,E1,E2,E3>& that)
-        {
-            *this = that();
-        }
-        template <int E0, int E1, int E2, int E3>
-        GLM_FUNC_DECL tvec4(glm::detail::swizzle3_4<T,tvec4<T>,E0,E1,E2,E3>& that)
-        {
-            *this = that();
-        }
-        template <int E0, int E1, int E2, int E3>
-        GLM_FUNC_DECL tvec4(glm::detail::swizzle4<T,tvec4<T>,E0,E1,E2,E3>& that)
+        GLM_FUNC_DECL tvec4(const glm::detail::swizzle<4,T,tvec4<T>,E0,E1,E2,E3>& that)
         {
             *this = that();
         }