fix missing forward for function object parameter (#2092)

Eisenwave · web-flow · commit 85e2fa321f45 · 2024-01-18T10:30:32.000-08:00
diff --git a/CppCoreGuidelines.md b/CppCoreGuidelines.md
@@ -3142,9 +3142,9 @@ In that case, and only that case, make the parameter `TP&&` where `TP` is a temp
 Usually you forward the entire parameter (or parameter pack, using `...`) exactly once on every static control flow path:
 
     template<class F, class... Args>
-    inline auto invoke(F f, Args&&... args)
+    inline decltype(auto) invoke(F&& f, Args&&... args)
     {
-        return f(forward<Args>(args)...);
+        return forward<F>(f)(forward<Args>(args)...);
     }
 
 ##### Example

Original file line number	Diff line number	Diff line change
@@ -3142,9 +3142,9 @@ In that case, and only that case, make the parameter `TP&&` where `TP` is a temp
`3142`	`3142`	Usually you forward the entire parameter (or parameter pack, using `...`) exactly once on every static control flow path:
`3143`	`3143`
`3144`	`3144`	`template<class F, class... Args>`
`3145`		`- inline auto invoke(F f, Args&&... args)`
	`3145`	`+ inline decltype(auto) invoke(F&& f, Args&&... args)`
`3146`	`3146`	`{`
`3147`		`- return f(forward<Args>(args)...);`
	`3147`	`+ return forward<F>(f)(forward<Args>(args)...);`
`3148`	`3148`	`}`
`3149`	`3149`
`3150`	`3150`	`##### Example`