MSVC build: Fix 'C4127: conditional expression is constant' warning

Stuart Dootson · murraycu · commit b74406a54b84 · 2019-10-25T12:57:31.000+02:00
diff --git a/sigc++/tuple-utils/tuple_for_each.h b/sigc++/tuple-utils/tuple_for_each.h
@@ -99,13 +99,11 @@ tuple_for_each(T&& t, T_extras&&... extras)
   // We use std::decay_t<> because tuple_size is not defined for references.
   constexpr auto size = std::tuple_size<std::decay_t<T>>::value;
 
-  if (size == 0)
+  if constexpr (size != 0)
   {
-    return;
+    detail::tuple_for_each_impl<T_visitor, size, T_extras...>::tuple_for_each(
+      std::forward<T>(t), std::forward<T_extras>(extras)...);
   }
-
-  detail::tuple_for_each_impl<T_visitor, size, T_extras...>::tuple_for_each(
-    std::forward<T>(t), std::forward<T_extras>(extras)...);
 }
 
 } // namespace internal

Original file line number	Diff line number	Diff line change
`@@ -99,13 +99,11 @@ tuple_for_each(T&& t, T_extras&&... extras)`
`99`	`99`	`// We use std::decay_t<> because tuple_size is not defined for references.`
`100`	`100`	`constexpr auto size = std::tuple_size<std::decay_t<T>>::value;`
`101`	`101`
`102`		`- if (size == 0)`
	`102`	`+ if constexpr (size != 0)`
`103`	`103`	`{`
`104`		`- return;`
	`104`	`+ detail::tuple_for_each_impl<T_visitor, size, T_extras...>::tuple_for_each(`
	`105`	`+ std::forward<T>(t), std::forward<T_extras>(extras)...);`
`105`	`106`	`}`
`106`		`-`
`107`		`- detail::tuple_for_each_impl<T_visitor, size, T_extras...>::tuple_for_each(`
`108`		`- std::forward<T>(t), std::forward<T_extras>(extras)...);`
`109`	`107`	`}`
`110`	`108`
`111`	`109`	`} // namespace internal`