Re: [PATCH] Remove redundant std::move in std::for_each

[Daniel Krügler]

2016-07-15 21:53 GMT+02:00 Jonathan Wakely :
> Returning a parameter will try to move anyway, so using std::move here
> is redundant (and clang even warns about it being redundant).
>
> * include/bits/stl_algo.h (for_each): Remove redundant _GLIBCXX_MOVE
> and adjust comment.

Actually I think this should also be reported as an LWG issue.

- Daniel

[PATCH] Remove redundant std::move in std::for_each

[Jonathan Wakely]

Returning a parameter will try to move anyway, so using std::move here
is redundant (and clang even warns about it being redundant).

* include/bits/stl_algo.h (for_each): Remove redundant _GLIBCXX_MOVE
and adjust comment.

Tested x86_64-linux, committed to trunk.

commit 54ee8abfe62dc97f725843f58fe896eebcc52db0
Author: redi 
Date:   Fri Jul 15 19:51:33 2016 +

Remove redundant std::move in std::for_each

* include/bits/stl_algo.h (for_each): Remove redundant _GLIBCXX_MOVE
and adjust comment.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@238399 
138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/libstdc++-v3/include/bits/stl_algo.h 
b/libstdc++-v3/include/bits/stl_algo.h
index a0820d4..ea0b56c 100644
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -3791,7 +3791,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
*  @param  __first  An input iterator.
*  @param  __last   An input iterator.
*  @param  __f  A unary function object.
-   *  @return   @p __f (std::move(@p __f) in C++0x).
+   *  @return   @p __f
*
*  Applies the function object @p __f to each element in the range
*  @p [first,last).  @p __f must not modify the order of the sequence.
@@ -3806,7 +3806,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
   __glibcxx_requires_valid_range(__first, __last);
   for (; __first != __last; ++__first)
__f(*__first);
-  return _GLIBCXX_MOVE(__f);
+  return __f; // N.B. [alg.foreach] says std::move(f) but it's redundant.
 }
 
   /**