[gcc r11-7221] libstdc++: Fix filesystem::rename on Windows [PR 98985]

Jonathan Wakely redi@gcc.gnu.org
Fri Feb 12 15:49:55 GMT 2021 

https://gcc.gnu.org/g:1dfd95f0a0ca1d9e6cbc00e6cbfd1fa20a98f312

commit r11-7221-g1dfd95f0a0ca1d9e6cbc00e6cbfd1fa20a98f312
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Feb 12 15:13:02 2021 +0000

    libstdc++: Fix filesystem::rename on Windows [PR 98985]
    
    The _wrename function won't overwrite an existing file, so use
    MoveFileEx instead. That allows renaming directories over files, which
    POSIX doesn't allow, so check for that case explicitly and report an
    error.
    
    Also document the deviation from the expected behaviour, and add a test
    for filesystem::rename which was previously missing.
    
    The Filesystem TS experimental::filesystem::rename doesn't have that
    extra code to handle directories correctly, so the relevant parts of the
    new test are not run on Windows.
    
    libstdc++-v3/ChangeLog:
    
            * doc/xml/manual/status_cxx2014.xml: Document implementation
            specific properties of std::experimental::filesystem::rename.
            * doc/xml/manual/status_cxx2017.xml: Document implementation
            specific properties of std::filesystem::rename.
            * doc/html/*: Regenerate.
            * src/c++17/fs_ops.cc (fs::rename): Implement correct behaviour
            for directories on Windows.
            * src/filesystem/ops-common.h (__gnu_posix::rename): Use
            MoveFileExW on Windows.
            * testsuite/27_io/filesystem/operations/rename.cc: New test.
            * testsuite/experimental/filesystem/operations/rename.cc: New test.

Diff:
---
 libstdc++-v3/doc/html/index.html                   |   2 +-
 libstdc++-v3/doc/html/manual/index.html            |   2 +-
 libstdc++-v3/doc/html/manual/intro.html            |   2 +-
 libstdc++-v3/doc/html/manual/status.html           |  35 +++-
 libstdc++-v3/doc/xml/manual/status_cxx2014.xml     |  26 ++-
 libstdc++-v3/doc/xml/manual/status_cxx2017.xml     |  15 +-
 libstdc++-v3/src/c++17/fs_ops.cc                   |  30 ++++
 libstdc++-v3/src/filesystem/ops-common.h           |  11 +-
 .../27_io/filesystem/operations/rename.cc          | 181 +++++++++++++++++++++
 .../experimental/filesystem/operations/rename.cc   | 180 ++++++++++++++++++++
 10 files changed, 474 insertions(+), 10 deletions(-)

diff --git a/libstdc++-v3/doc/html/index.html b/libstdc++-v3/doc/html/index.html
index 587d4ee819a..772009a816b 100644
--- a/libstdc++-v3/doc/html/index.html
+++ b/libstdc++-v3/doc/html/index.html
@@ -23,7 +23,7 @@
     </p></div></div></div><hr /></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="book"><a href="manual/index.html">The GNU C++ Library Manual</a></span></dt><dd><dl><dt><span class="part"><a href="manual/intro.html">I. 
   Introduction
   
-</a></span></dt><dd><dl><dt><span class="chapter"><a href="manual/status.html">1. Status</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="manual/status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.2014">C++ 2014</a></span></dt><dt><span class="section"><a href="manual/status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="manual/status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="manual/status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="manual/license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="manual/license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="manual/license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="manual/bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="manual/bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="manual/bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="manual/setup.html">2. Setup</a></span></dt><dd><dl><dt><span class="section"><a href="manual/setup.html#manual.intro.setup.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="manual/configure.html">Configure</a></span></dt><dt><span class="section"><a href="manual/make.html">Make</a></span></dt></dl></dd><dt><span class="chapter"><a href="manual/using.html">3. Using</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using.html#manual.intro.using.flags">Command Options</a></span></dt><dt><span class="section"><a href="manual/using_headers.html">Headers</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.all">Header Files</a></span></dt><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.mixing">Mixing Headers</a></span></dt><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.cheaders">The C Headers and <code class="code">namespace std</code></a></span></dt><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.pre">Precompiled Headers</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_macros.html">Macros</a></span></dt><dt><span class="section"><a href="manual/using_dual_abi.html">Dual ABI</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_dual_abi.html#manual.intro.using.abi.trouble">Troubleshooting</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_namespaces.html">Namespaces</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_namespaces.html#manual.intro.using.namespaces.all">Available Namespaces</a></span></dt><dt><span class="section"><a href="manual/using_namespaces.html#manual.intro.using.namespaces.std">namespace std</a></span></dt><dt><span class="section"><a href="manual/using_namespaces.html#manual.intro.using.namespaces.comp">Using Namespace Composition</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_dynamic_or_shared.html">Linking</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_dynamic_or_shared.html#manual.intro.using.linkage.freestanding">Almost Nothing</a></span></dt><dt><span class="section"><a href="manual/using_dynamic_or_shared.html#manual.intro.using.linkage.dynamic">Finding Dynamic or Shared Libraries</a></span></dt><dt><span class="section"><a href="manual/using_dynamic_or_shared.html#manual.intro.using.linkage.experimental">Experimental Library Extensions</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_concurrency.html">Concurrency</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.thread_safety">Thread Safety</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.atomics">Atomics</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.io">IO</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.structure">Structure</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.defaults">Defaults</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.future">Future</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.alt">Alternatives</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.containers">Containers</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_exceptions.html">Exceptions</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.safety">Exception Safety</a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.propagating">Exception Neutrality</a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.no">Doing without</a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.compat">Compatibility</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_exceptions.html#using.exception.compat.c">With <code class="literal">C</code></a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#using.exception.compat.posix">With <code class="literal">POSIX</code> thread cancellation</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="manual/debug.html">Debugging Support</a></span></dt><dd><dl><dt><span class="section"><a href="manual/debug.html#debug.compiler">Using <span class="command"><strong>g++</strong></span></a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.req">Debug Versions of Library Binary Files</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.memory">Memory Leak Hunting</a></span></dt><dd><dl><dt><span class="section"><a href="manual/debug.html#debug.memory.mtalloc">Non-memory leaks in Pool and MT allocators</a></span></dt></dl></dd><dt><span class="section"><a href="manual/debug.html#debug.races">Data Race Hunting</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.gdb">Using <span class="command"><strong>gdb</strong></span></a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.exceptions">Tracking uncaught exceptions</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.debug_mode">Debug Mode</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.compile_time_checks">Compile Time Checking</a></span></dt></dl></dd></dl></dd></dl></dd><dt><span class="part"><a href="manual/std_contents.html">II. 
+</a></span></dt><dd><dl><dt><span class="chapter"><a href="manual/status.html">1. Status</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="manual/status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.2014">C++ 2014</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2014.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2014.filesystemts">Filesystem TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="manual/status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="manual/status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="manual/status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="manual/status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="manual/license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="manual/license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="manual/license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="manual/bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="manual/bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="manual/bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="manual/setup.html">2. Setup</a></span></dt><dd><dl><dt><span class="section"><a href="manual/setup.html#manual.intro.setup.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="manual/configure.html">Configure</a></span></dt><dt><span class="section"><a href="manual/make.html">Make</a></span></dt></dl></dd><dt><span class="chapter"><a href="manual/using.html">3. Using</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using.html#manual.intro.using.flags">Command Options</a></span></dt><dt><span class="section"><a href="manual/using_headers.html">Headers</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.all">Header Files</a></span></dt><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.mixing">Mixing Headers</a></span></dt><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.cheaders">The C Headers and <code class="code">namespace std</code></a></span></dt><dt><span class="section"><a href="manual/using_headers.html#manual.intro.using.headers.pre">Precompiled Headers</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_macros.html">Macros</a></span></dt><dt><span class="section"><a href="manual/using_dual_abi.html">Dual ABI</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_dual_abi.html#manual.intro.using.abi.trouble">Troubleshooting</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_namespaces.html">Namespaces</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_namespaces.html#manual.intro.using.namespaces.all">Available Namespaces</a></span></dt><dt><span class="section"><a href="manual/using_namespaces.html#manual.intro.using.namespaces.std">namespace std</a></span></dt><dt><span class="section"><a href="manual/using_namespaces.html#manual.intro.using.namespaces.comp">Using Namespace Composition</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_dynamic_or_shared.html">Linking</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_dynamic_or_shared.html#manual.intro.using.linkage.freestanding">Almost Nothing</a></span></dt><dt><span class="section"><a href="manual/using_dynamic_or_shared.html#manual.intro.using.linkage.dynamic">Finding Dynamic or Shared Libraries</a></span></dt><dt><span class="section"><a href="manual/using_dynamic_or_shared.html#manual.intro.using.linkage.experimental">Experimental Library Extensions</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_concurrency.html">Concurrency</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.thread_safety">Thread Safety</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.atomics">Atomics</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.io">IO</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.structure">Structure</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.defaults">Defaults</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.future">Future</a></span></dt><dt><span class="section"><a href="manual/using_concurrency.html#concurrency.io.alt">Alternatives</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_concurrency.html#manual.intro.using.concurrency.containers">Containers</a></span></dt></dl></dd><dt><span class="section"><a href="manual/using_exceptions.html">Exceptions</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.safety">Exception Safety</a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.propagating">Exception Neutrality</a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.no">Doing without</a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#intro.using.exception.compat">Compatibility</a></span></dt><dd><dl><dt><span class="section"><a href="manual/using_exceptions.html#using.exception.compat.c">With <code class="literal">C</code></a></span></dt><dt><span class="section"><a href="manual/using_exceptions.html#using.exception.compat.posix">With <code class="literal">POSIX</code> thread cancellation</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="manual/debug.html">Debugging Support</a></span></dt><dd><dl><dt><span class="section"><a href="manual/debug.html#debug.compiler">Using <span class="command"><strong>g++</strong></span></a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.req">Debug Versions of Library Binary Files</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.memory">Memory Leak Hunting</a></span></dt><dd><dl><dt><span class="section"><a href="manual/debug.html#debug.memory.mtalloc">Non-memory leaks in Pool and MT allocators</a></span></dt></dl></dd><dt><span class="section"><a href="manual/debug.html#debug.races">Data Race Hunting</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.gdb">Using <span class="command"><strong>gdb</strong></span></a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.exceptions">Tracking uncaught exceptions</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.debug_mode">Debug Mode</a></span></dt><dt><span class="section"><a href="manual/debug.html#debug.compile_time_checks">Compile Time Checking</a></span></dt></dl></dd></dl></dd></dl></dd><dt><span class="part"><a href="manual/std_contents.html">II. 
     Standard Contents
   </a></span></dt><dd><dl><dt><span class="chapter"><a href="manual/support.html">4. 
   Support
diff --git a/libstdc++-v3/doc/html/manual/index.html b/libstdc++-v3/doc/html/manual/index.html
index d66de295f11..24a4ba97baf 100644
--- a/libstdc++-v3/doc/html/manual/index.html
+++ b/libstdc++-v3/doc/html/manual/index.html
@@ -4,7 +4,7 @@
     </p></div></div><hr /></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="part"><a href="intro.html">I. 
   Introduction
   
-</a></span></dt><dd><dl><dt><span class="chapter"><a href="status.html">1. Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2014">C++ 2014</a></span></dt><dt><span class="section"><a href="status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="setup.html">2. Setup</a></span></dt><dd><dl><dt><span class="section"><a href="setup.html#manual.intro.setup.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="configure.html">Configure</a></span></dt><dt><span class="section"><a href="make.html">Make</a></span></dt></dl></dd><dt><span class="chapter"><a href="using.html">3. Using</a></span></dt><dd><dl><dt><span class="section"><a href="using.html#manual.intro.using.flags">Command Options</a></span></dt><dt><span class="section"><a href="using_headers.html">Headers</a></span></dt><dd><dl><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.all">Header Files</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.mixing">Mixing Headers</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.cheaders">The C Headers and <code class="code">namespace std</code></a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.pre">Precompiled Headers</a></span></dt></dl></dd><dt><span class="section"><a href="using_macros.html">Macros</a></span></dt><dt><span class="section"><a href="using_dual_abi.html">Dual ABI</a></span></dt><dd><dl><dt><span class="section"><a href="using_dual_abi.html#manual.intro.using.abi.trouble">Troubleshooting</a></span></dt></dl></dd><dt><span class="section"><a href="using_namespaces.html">Namespaces</a></span></dt><dd><dl><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.all">Available Namespaces</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.std">namespace std</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.comp">Using Namespace Composition</a></span></dt></dl></dd><dt><span class="section"><a href="using_dynamic_or_shared.html">Linking</a></span></dt><dd><dl><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.freestanding">Almost Nothing</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.dynamic">Finding Dynamic or Shared Libraries</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.experimental">Experimental Library Extensions</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html">Concurrency</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.thread_safety">Thread Safety</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.atomics">Atomics</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.io">IO</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#concurrency.io.structure">Structure</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.defaults">Defaults</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.future">Future</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.alt">Alternatives</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.containers">Containers</a></span></dt></dl></dd><dt><span class="section"><a href="using_exceptions.html">Exceptions</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.safety">Exception Safety</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.propagating">Exception Neutrality</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.no">Doing without</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.compat">Compatibility</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.c">With <code class="literal">C</code></a></span></dt><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.posix">With <code class="literal">POSIX</code> thread cancellation</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="debug.html">Debugging Support</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.compiler">Using <span class="command"><strong>g++</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.req">Debug Versions of Library Binary Files</a></span></dt><dt><span class="section"><a href="debug.html#debug.memory">Memory Leak Hunting</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.memory.mtalloc">Non-memory leaks in Pool and MT allocators</a></span></dt></dl></dd><dt><span class="section"><a href="debug.html#debug.races">Data Race Hunting</a></span></dt><dt><span class="section"><a href="debug.html#debug.gdb">Using <span class="command"><strong>gdb</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.exceptions">Tracking uncaught exceptions</a></span></dt><dt><span class="section"><a href="debug.html#debug.debug_mode">Debug Mode</a></span></dt><dt><span class="section"><a href="debug.html#debug.compile_time_checks">Compile Time Checking</a></span></dt></dl></dd></dl></dd></dl></dd><dt><span class="part"><a href="std_contents.html">II. 
+</a></span></dt><dd><dl><dt><span class="chapter"><a href="status.html">1. Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2014">C++ 2014</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.filesystemts">Filesystem TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="setup.html">2. Setup</a></span></dt><dd><dl><dt><span class="section"><a href="setup.html#manual.intro.setup.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="configure.html">Configure</a></span></dt><dt><span class="section"><a href="make.html">Make</a></span></dt></dl></dd><dt><span class="chapter"><a href="using.html">3. Using</a></span></dt><dd><dl><dt><span class="section"><a href="using.html#manual.intro.using.flags">Command Options</a></span></dt><dt><span class="section"><a href="using_headers.html">Headers</a></span></dt><dd><dl><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.all">Header Files</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.mixing">Mixing Headers</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.cheaders">The C Headers and <code class="code">namespace std</code></a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.pre">Precompiled Headers</a></span></dt></dl></dd><dt><span class="section"><a href="using_macros.html">Macros</a></span></dt><dt><span class="section"><a href="using_dual_abi.html">Dual ABI</a></span></dt><dd><dl><dt><span class="section"><a href="using_dual_abi.html#manual.intro.using.abi.trouble">Troubleshooting</a></span></dt></dl></dd><dt><span class="section"><a href="using_namespaces.html">Namespaces</a></span></dt><dd><dl><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.all">Available Namespaces</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.std">namespace std</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.comp">Using Namespace Composition</a></span></dt></dl></dd><dt><span class="section"><a href="using_dynamic_or_shared.html">Linking</a></span></dt><dd><dl><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.freestanding">Almost Nothing</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.dynamic">Finding Dynamic or Shared Libraries</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.experimental">Experimental Library Extensions</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html">Concurrency</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.thread_safety">Thread Safety</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.atomics">Atomics</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.io">IO</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#concurrency.io.structure">Structure</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.defaults">Defaults</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.future">Future</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.alt">Alternatives</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.containers">Containers</a></span></dt></dl></dd><dt><span class="section"><a href="using_exceptions.html">Exceptions</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.safety">Exception Safety</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.propagating">Exception Neutrality</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.no">Doing without</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.compat">Compatibility</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.c">With <code class="literal">C</code></a></span></dt><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.posix">With <code class="literal">POSIX</code> thread cancellation</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="debug.html">Debugging Support</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.compiler">Using <span class="command"><strong>g++</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.req">Debug Versions of Library Binary Files</a></span></dt><dt><span class="section"><a href="debug.html#debug.memory">Memory Leak Hunting</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.memory.mtalloc">Non-memory leaks in Pool and MT allocators</a></span></dt></dl></dd><dt><span class="section"><a href="debug.html#debug.races">Data Race Hunting</a></span></dt><dt><span class="section"><a href="debug.html#debug.gdb">Using <span class="command"><strong>gdb</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.exceptions">Tracking uncaught exceptions</a></span></dt><dt><span class="section"><a href="debug.html#debug.debug_mode">Debug Mode</a></span></dt><dt><span class="section"><a href="debug.html#debug.compile_time_checks">Compile Time Checking</a></span></dt></dl></dd></dl></dd></dl></dd><dt><span class="part"><a href="std_contents.html">II. 
     Standard Contents
   </a></span></dt><dd><dl><dt><span class="chapter"><a href="support.html">4. 
   Support
diff --git a/libstdc++-v3/doc/html/manual/intro.html b/libstdc++-v3/doc/html/manual/intro.html
index 0a99c8fc71a..3604e0a1d45 100644
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@@ -5,4 +5,4 @@
 </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="index.html">Prev</a> </td><th width="60%" align="center">The GNU C++ Library Manual</th><td width="20%" align="right"> <a accesskey="n" href="status.html">Next</a></td></tr></table><hr /></div><div class="part"><div class="titlepage"><div><div><h1 class="title"><a id="manual.intro"></a>Part I. 
   Introduction
   <a id="id-1.3.3.1.1.1" class="indexterm"></a>
-</h1></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="chapter"><a href="status.html">1. Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2014">C++ 2014</a></span></dt><dt><span class="section"><a href="status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="setup.html">2. Setup</a></span></dt><dd><dl><dt><span class="section"><a href="setup.html#manual.intro.setup.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="configure.html">Configure</a></span></dt><dt><span class="section"><a href="make.html">Make</a></span></dt></dl></dd><dt><span class="chapter"><a href="using.html">3. Using</a></span></dt><dd><dl><dt><span class="section"><a href="using.html#manual.intro.using.flags">Command Options</a></span></dt><dt><span class="section"><a href="using_headers.html">Headers</a></span></dt><dd><dl><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.all">Header Files</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.mixing">Mixing Headers</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.cheaders">The C Headers and <code class="code">namespace std</code></a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.pre">Precompiled Headers</a></span></dt></dl></dd><dt><span class="section"><a href="using_macros.html">Macros</a></span></dt><dt><span class="section"><a href="using_dual_abi.html">Dual ABI</a></span></dt><dd><dl><dt><span class="section"><a href="using_dual_abi.html#manual.intro.using.abi.trouble">Troubleshooting</a></span></dt></dl></dd><dt><span class="section"><a href="using_namespaces.html">Namespaces</a></span></dt><dd><dl><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.all">Available Namespaces</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.std">namespace std</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.comp">Using Namespace Composition</a></span></dt></dl></dd><dt><span class="section"><a href="using_dynamic_or_shared.html">Linking</a></span></dt><dd><dl><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.freestanding">Almost Nothing</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.dynamic">Finding Dynamic or Shared Libraries</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.experimental">Experimental Library Extensions</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html">Concurrency</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.thread_safety">Thread Safety</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.atomics">Atomics</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.io">IO</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#concurrency.io.structure">Structure</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.defaults">Defaults</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.future">Future</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.alt">Alternatives</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.containers">Containers</a></span></dt></dl></dd><dt><span class="section"><a href="using_exceptions.html">Exceptions</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.safety">Exception Safety</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.propagating">Exception Neutrality</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.no">Doing without</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.compat">Compatibility</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.c">With <code class="literal">C</code></a></span></dt><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.posix">With <code class="literal">POSIX</code> thread cancellation</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="debug.html">Debugging Support</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.compiler">Using <span class="command"><strong>g++</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.req">Debug Versions of Library Binary Files</a></span></dt><dt><span class="section"><a href="debug.html#debug.memory">Memory Leak Hunting</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.memory.mtalloc">Non-memory leaks in Pool and MT allocators</a></span></dt></dl></dd><dt><span class="section"><a href="debug.html#debug.races">Data Race Hunting</a></span></dt><dt><span class="section"><a href="debug.html#debug.gdb">Using <span class="command"><strong>gdb</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.exceptions">Tracking uncaught exceptions</a></span></dt><dt><span class="section"><a href="debug.html#debug.debug_mode">Debug Mode</a></span></dt><dt><span class="section"><a href="debug.html#debug.compile_time_checks">Compile Time Checking</a></span></dt></dl></dd></dl></dd></dl></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="index.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="status.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">The GNU C++ Library Manual </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 1. Status</td></tr></table></div></body></html>
\ No newline at end of file
+</h1></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="chapter"><a href="status.html">1. Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2014">C++ 2014</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.filesystemts">Filesystem TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="setup.html">2. Setup</a></span></dt><dd><dl><dt><span class="section"><a href="setup.html#manual.intro.setup.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="configure.html">Configure</a></span></dt><dt><span class="section"><a href="make.html">Make</a></span></dt></dl></dd><dt><span class="chapter"><a href="using.html">3. Using</a></span></dt><dd><dl><dt><span class="section"><a href="using.html#manual.intro.using.flags">Command Options</a></span></dt><dt><span class="section"><a href="using_headers.html">Headers</a></span></dt><dd><dl><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.all">Header Files</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.mixing">Mixing Headers</a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.cheaders">The C Headers and <code class="code">namespace std</code></a></span></dt><dt><span class="section"><a href="using_headers.html#manual.intro.using.headers.pre">Precompiled Headers</a></span></dt></dl></dd><dt><span class="section"><a href="using_macros.html">Macros</a></span></dt><dt><span class="section"><a href="using_dual_abi.html">Dual ABI</a></span></dt><dd><dl><dt><span class="section"><a href="using_dual_abi.html#manual.intro.using.abi.trouble">Troubleshooting</a></span></dt></dl></dd><dt><span class="section"><a href="using_namespaces.html">Namespaces</a></span></dt><dd><dl><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.all">Available Namespaces</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.std">namespace std</a></span></dt><dt><span class="section"><a href="using_namespaces.html#manual.intro.using.namespaces.comp">Using Namespace Composition</a></span></dt></dl></dd><dt><span class="section"><a href="using_dynamic_or_shared.html">Linking</a></span></dt><dd><dl><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.freestanding">Almost Nothing</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.dynamic">Finding Dynamic or Shared Libraries</a></span></dt><dt><span class="section"><a href="using_dynamic_or_shared.html#manual.intro.using.linkage.experimental">Experimental Library Extensions</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html">Concurrency</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.prereq">Prerequisites</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.thread_safety">Thread Safety</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.atomics">Atomics</a></span></dt><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.io">IO</a></span></dt><dd><dl><dt><span class="section"><a href="using_concurrency.html#concurrency.io.structure">Structure</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.defaults">Defaults</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.future">Future</a></span></dt><dt><span class="section"><a href="using_concurrency.html#concurrency.io.alt">Alternatives</a></span></dt></dl></dd><dt><span class="section"><a href="using_concurrency.html#manual.intro.using.concurrency.containers">Containers</a></span></dt></dl></dd><dt><span class="section"><a href="using_exceptions.html">Exceptions</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.safety">Exception Safety</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.propagating">Exception Neutrality</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.no">Doing without</a></span></dt><dt><span class="section"><a href="using_exceptions.html#intro.using.exception.compat">Compatibility</a></span></dt><dd><dl><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.c">With <code class="literal">C</code></a></span></dt><dt><span class="section"><a href="using_exceptions.html#using.exception.compat.posix">With <code class="literal">POSIX</code> thread cancellation</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="debug.html">Debugging Support</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.compiler">Using <span class="command"><strong>g++</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.req">Debug Versions of Library Binary Files</a></span></dt><dt><span class="section"><a href="debug.html#debug.memory">Memory Leak Hunting</a></span></dt><dd><dl><dt><span class="section"><a href="debug.html#debug.memory.mtalloc">Non-memory leaks in Pool and MT allocators</a></span></dt></dl></dd><dt><span class="section"><a href="debug.html#debug.races">Data Race Hunting</a></span></dt><dt><span class="section"><a href="debug.html#debug.gdb">Using <span class="command"><strong>gdb</strong></span></a></span></dt><dt><span class="section"><a href="debug.html#debug.exceptions">Tracking uncaught exceptions</a></span></dt><dt><span class="section"><a href="debug.html#debug.debug_mode">Debug Mode</a></span></dt><dt><span class="section"><a href="debug.html#debug.compile_time_checks">Compile Time Checking</a></span></dt></dl></dd></dl></dd></dl></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="index.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="status.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">The GNU C++ Library Manual </td><td width="20%" align="center"><a accesskey="h" href="../index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 1. Status</td></tr></table></div></body></html>
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diff --git a/libstdc++-v3/doc/html/manual/status.html b/libstdc++-v3/doc/html/manual/status.html
index daa74a85c6f..46c6ee73998 100644
--- a/libstdc++-v3/doc/html/manual/status.html
+++ b/libstdc++-v3/doc/html/manual/status.html
@@ -2,7 +2,7 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 1. Status</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="intro.html" title="Part I.  Introduction" /><link rel="prev" href="intro.html" title="Part I.  Introduction" /><link rel="next" href="license.html" title="License" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 1. Status</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="intro.html">Prev</a> </td><th width="60%" align="center">Part I. 
   Introduction
   
-</th><td width="20%" align="right"> <a accesskey="n" href="license.html">Next</a></td></tr></table><hr /></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="manual.intro.status"></a>Chapter 1. Status</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="section"><a href="status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2014">C++ 2014</a></span></dt><dt><span class="section"><a href="status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.intro.status.iso"></a>Implementation Status</h2></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.1998"></a>C++ 1998/2003</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.1998.status"></a>Implementation Status</h4></div></div></div><p>
+</th><td width="20%" align="right"> <a accesskey="n" href="license.html">Next</a></td></tr></table><hr /></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="manual.intro.status"></a>Chapter 1. Status</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="section"><a href="status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2014">C++ 2014</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.filesystemts">Filesystem TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.intro.status.iso"></a>Implementation Status</h2></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.1998"></a>C++ 1998/2003</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.1998.status"></a>Implementation Status</h4></div></div></div><p>
 This status table is based on the table of contents of ISO/IEC 14882:2003.
 </p><p>
 This section describes the C++ support in mainline GCC, not in any
@@ -536,7 +536,24 @@ not in any particular release.
 	Link with
 	<a class="link" href="using_dynamic_or_shared.html#manual.intro.using.linkage.experimental" title="Experimental Library Extensions">
 	<code class="option">-lstdc++fs</code></a>
-      </td></tr></tbody></table></div></div><br class="table-break" /></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.2017"></a>C++ 2017</h3></div></div></div><p>
+      </td></tr></tbody></table></div></div><br class="table-break" /><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.2014.specific"></a>Implementation Specific Behavior</h4></div></div></div><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="iso.2014.filesystemts"></a>Filesystem TS</h5></div></div></div><p>
+      <span class="emphasis"><em>2.1 POSIX conformance [fs.conform.9945]</em></span>
+      The behavior of the filesystem library implementation will depend on
+      the target operating system. Some features will not be supported
+      on some targets. Symbolic links and file permissions
+      are not supported on Windows.
+    </p><p>
+      <span class="emphasis"><em>15.30 Rename [fs.op.rename]</em></span>
+      On Windows, <code class="code">experimental::filesystem::rename</code>
+      is implemented by calling <code class="code">MoveFileExW</code> and so
+      does not meet the requirements of POSIX <code class="code">rename</code>
+      when one or both of the paths resolves to an existing directory.
+      Specifically, it is possible to rename a directory so it replaces
+      a non-directory (POSIX requires an error in that case),
+      and it is not possible to rename a directory to replace another
+      directory (POSIX requires that to work if the directory being
+      replaced is empty).
+    </p></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.2017"></a>C++ 2017</h3></div></div></div><p>
 In this implementation the <code class="literal">-std=gnu++17</code> or
 <code class="literal">-std=c++17</code> flag must be used to enable language
 and library
@@ -1076,7 +1093,8 @@ since C++14 and the implementation is complete.
       <span class="emphasis"><em>30.10.2.1 [fs.conform.9945]</em></span>
       The behavior of the filesystem library implementation will depend on
       the target operating system. Some features will not be supported
-      on some targets.
+      on some targets. Symbolic links and file permissions
+      are not supported on Windows.
    </p><p>
       <span class="emphasis"><em>30.10.5 [fs.filesystem.syn]</em></span>
       The clock used for file times is an unspecified type
@@ -1099,7 +1117,16 @@ since C++14 and the implementation is complete.
    </p><p>
       <span class="emphasis"><em>30.10.15.4 [fs.op.file_size]</em></span>
       If <code class="code">!is_regular_file(p)</code>, an error is reported.
-   </p><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="iso.2017.par2ts"></a>Parallelism 2 TS</h5></div></div></div><p>
+   </p><p>
+      <span class="emphasis"><em>30.10.15.32 [fs.op.rename]</em></span>
+      On Windows, <code class="code">filesystem::rename</code>
+      is implemented by calling <code class="code">MoveFileExW</code> and so
+      does not meet the requirements of POSIX <code class="code">rename</code>
+      when one or both of the paths resolves to an existing directory.
+      Specifically, it is not possible to rename a directory to replace another
+      directory (POSIX requires that to work if the directory being
+      replaced is empty).
+    </p><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="iso.2017.par2ts"></a>Parallelism 2 TS</h5></div></div></div><p>
         <span class="emphasis"><em>9.3 [parallel.simd.abi]</em></span>
         <code class="code">max_fixed_size<T></code> is 32, except when targetting
         AVX512BW and <code class="code">sizeof(T)</code> is 1.
diff --git a/libstdc++-v3/doc/xml/manual/status_cxx2014.xml b/libstdc++-v3/doc/xml/manual/status_cxx2014.xml
index 2cf5f629efb..5dc287707d8 100644
--- a/libstdc++-v3/doc/xml/manual/status_cxx2014.xml
+++ b/libstdc++-v3/doc/xml/manual/status_cxx2014.xml
@@ -1717,9 +1717,33 @@ not in any particular release.
       </entry>
     </row>
 
-
   </tbody>
 </tgroup>
 </table>
 
+<section xml:id="iso.2014.specific" xreflabel="Implementation Specific"><info><title>Implementation Specific Behavior</title></info>
+
+  <section xml:id="iso.2014.filesystemts" xreflabel="Implementation Specific Behavior of the Filesystem TS"><info><title>Filesystem TS</title></info>
+    <para>
+      <emphasis>2.1 POSIX conformance [fs.conform.9945]</emphasis>
+      The behavior of the filesystem library implementation will depend on
+      the target operating system. Some features will not be supported
+      on some targets. Symbolic links and file permissions
+      are not supported on Windows.
+    </para>
+    <para>
+      <emphasis>15.30 Rename [fs.op.rename]</emphasis>
+      On Windows, <code>experimental::filesystem::rename</code>
+      is implemented by calling <code>MoveFileExW</code> and so
+      does not meet the requirements of POSIX <code>rename</code>
+      when one or both of the paths resolves to an existing directory.
+      Specifically, it is possible to rename a directory so it replaces
+      a non-directory (POSIX requires an error in that case),
+      and it is not possible to rename a directory to replace another
+      directory (POSIX requires that to work if the directory being
+      replaced is empty).
+    </para>
+  </section>
+</section>
+
 </section>
diff --git a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
index b1c12bd3799..7f64c47bdfe 100644
--- a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
+++ b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
@@ -2992,7 +2992,8 @@ since C++14 and the implementation is complete.
       <emphasis>30.10.2.1 [fs.conform.9945]</emphasis>
       The behavior of the filesystem library implementation will depend on
       the target operating system. Some features will not be supported
-      on some targets.
+      on some targets. Symbolic links and file permissions
+      are not supported on Windows.
    </para>
 
    <para>
@@ -3025,6 +3026,18 @@ since C++14 and the implementation is complete.
       If <code>!is_regular_file(p)</code>, an error is reported.
    </para>
 
+    <para>
+      <emphasis>30.10.15.32 [fs.op.rename]</emphasis>
+      On Windows, <code>filesystem::rename</code>
+      is implemented by calling <code>MoveFileExW</code> and so
+      does not meet the requirements of POSIX <code>rename</code>
+      when one or both of the paths resolves to an existing directory.
+      Specifically, it is not possible to rename a directory to replace another
+      directory (POSIX requires that to work if the directory being
+      replaced is empty).
+    </para>
+
+
    <section xml:id="iso.2017.par2ts" xreflabel="Implementation Specific Behavior of the Parallelism 2 TS"><info><title>Parallelism 2 TS</title></info>
 
      <para>
diff --git a/libstdc++-v3/src/c++17/fs_ops.cc b/libstdc++-v3/src/c++17/fs_ops.cc
index 3817655471c..3e1671e611e 100644
--- a/libstdc++-v3/src/c++17/fs_ops.cc
+++ b/libstdc++-v3/src/c++17/fs_ops.cc
@@ -1394,6 +1394,36 @@ fs::rename(const path& from, const path& to)
 void
 fs::rename(const path& from, const path& to, error_code& ec) noexcept
 {
+#if _GLIBCXX_FILESYSTEM_IS_WINDOWS
+  const auto to_status = fs::status(to, ec);
+  if (to_status.type() == file_type::not_found)
+    ec.clear();
+  else if (ec)
+    return;
+
+  if (fs::exists(to_status))
+  {
+    const auto from_status = fs::status(from, ec);
+    if (ec)
+      return;
+
+    if (fs::is_directory(to_status))
+    {
+      if (!fs::is_directory(from_status))
+      {
+	// Cannot rename a non-directory over an existing directory.
+	ec = std::make_error_code(std::errc::is_a_directory);
+	return;
+      }
+    }
+    else if (fs::is_directory(from_status))
+    {
+      // Cannot rename a directory over an existing non-directory.
+      ec = std::make_error_code(std::errc::not_a_directory);
+      return;
+    }
+  }
+#endif
   if (posix::rename(from.c_str(), to.c_str()))
     ec.assign(errno, std::generic_category());
   else
diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h
index 118256a0d22..529d4e09016 100644
--- a/libstdc++-v3/src/filesystem/ops-common.h
+++ b/libstdc++-v3/src/filesystem/ops-common.h
@@ -104,7 +104,16 @@ namespace __gnu_posix
 #endif
 
   inline int rename(const wchar_t* oldname, const wchar_t* newname)
-  { return _wrename(oldname, newname); }
+  {
+    if (MoveFileExW(oldname, newname,
+		    MOVEFILE_REPLACE_EXISTING | MOVEFILE_COPY_ALLOWED))
+      return 0;
+    if (GetLastError() == ERROR_ACCESS_DENIED)
+      errno = EACCES;
+    else
+      errno = EIO;
+    return -1;
+  }
 
   inline int truncate(const wchar_t* path, _off64_t length)
   {
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/operations/rename.cc b/libstdc++-v3/testsuite/27_io/filesystem/operations/rename.cc
new file mode 100644
index 00000000000..c873811ad93
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/filesystem/operations/rename.cc
@@ -0,0 +1,181 @@
+// Copyright (C) 2021 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++17" }
+// { dg-do run { target c++17 } }
+// { dg-require-filesystem-ts "" }
+
+#include <filesystem>
+#include <testsuite_hooks.h>
+#include <testsuite_fs.h>
+
+namespace fs = std::filesystem;
+
+void
+test01()
+{
+  std::error_code ec;
+  const std::error_code bad_ec = make_error_code(std::errc::invalid_argument);
+
+  auto p1 = __gnu_test::nonexistent_path();
+  auto p2 = __gnu_test::nonexistent_path();
+
+  fs::rename(p1, p2, ec);
+  VERIFY( ec );
+
+  ec.clear();
+  fs::rename(p1, "", ec);
+  VERIFY( ec );
+
+  ec.clear();
+  fs::rename("", p1, ec);
+  VERIFY( ec );
+
+  ec = bad_ec;
+  std::ofstream{p1}; // create file
+  fs::rename(p1, p1, ec); // no-op
+  VERIFY( !ec );
+  VERIFY( is_regular_file(p1) );
+
+  ec.clear();
+  rename(p2, p1, ec);
+  VERIFY( ec );
+  VERIFY( ec.value() == ENOENT );
+  VERIFY( is_regular_file(p1) );
+
+  ec = bad_ec;
+  fs::rename(p1, p2, ec);
+  VERIFY( !ec );
+  VERIFY( !exists(p1) );
+  VERIFY( is_regular_file(p2) );
+
+  ec = bad_ec;
+  std::ofstream{p1}; // create file
+  fs::rename(p1, p2, ec);
+  VERIFY( !ec );
+  VERIFY( !exists(p1) );
+  VERIFY( is_regular_file(p2) );
+
+  fs::remove(p2, ec);
+}
+
+void
+test_symlinks()
+{
+#if defined(__MINGW32__) || defined(__MINGW64__)
+  // No symlink support
+#else
+  std::error_code ec;
+  const std::error_code bad_ec = make_error_code(std::errc::invalid_argument);
+
+  const auto dir = __gnu_test::nonexistent_path();
+  fs::create_directory(dir);
+
+  create_symlink(dir/"nonesuch", dir/"link");  // dangling symlink
+  ec = bad_ec;
+  fs::rename(dir/"link", dir/"newlink", ec);
+  VERIFY( !ec );
+  VERIFY( !exists(symlink_status(dir/"link")) );
+  VERIFY( is_symlink(dir/"newlink") );
+
+  __gnu_test::scoped_file f(dir/"file");
+  create_symlink(dir/"file", dir/"link");
+  ec = bad_ec;
+  fs::rename(dir/"link", dir/"newerlink", ec);
+  VERIFY( !ec );
+  VERIFY( !exists(symlink_status(dir/"link")) );
+  VERIFY( is_symlink(dir/"newerlink") );
+  VERIFY( is_regular_file(dir/"file") );
+
+  fs::remove_all(dir, ec);
+  f.path.clear();
+#endif
+}
+
+void
+test_directories()
+{
+  std::error_code ec;
+  const std::error_code bad_ec = make_error_code(std::errc::invalid_argument);
+
+  const auto dir = __gnu_test::nonexistent_path();
+  fs::create_directory(dir);
+  __gnu_test::scoped_file f(dir/"file");
+  fs::create_directory(dir/"subdir");
+
+  // Rename directory.
+  ec = bad_ec;
+  fs::rename(dir/"subdir", dir/"subdir2", ec);
+  VERIFY( !ec );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( !exists(dir/"subdir") );
+
+  // Cannot rename a directory to a sub-directory of itself.
+  fs::rename(dir/"subdir2", dir/"subdir2/subsubdir", ec);
+  VERIFY( ec );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( !exists(dir/"subdir2"/"subsubdir") );
+
+  // Cannot rename a file to the name of an existing directory.
+  ec.clear();
+  fs::rename(dir/"file", dir/"subdir2", ec);
+  VERIFY( ec );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( is_regular_file(dir/"file") );
+
+  // Cannot rename a directory to the name of an existing non-directory
+  ec.clear();
+  fs::rename(dir/"subdir2", dir/"file", ec);
+  VERIFY( ec );
+  VERIFY( is_regular_file(dir/"file") );
+  VERIFY( is_directory(dir/"subdir2") );
+
+  // Cannot rename directory to the name of a non-empty directory.
+  ec.clear();
+  __gnu_test::scoped_file f2(dir/"subdir2/file");
+  fs::create_directory(dir/"subdir");
+  fs::rename(dir/"subdir", dir/"subdir2", ec);
+  VERIFY( ec );
+  VERIFY( is_directory(dir/"subdir") );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( is_regular_file(dir/"subdir2/file") );
+
+#if defined(__MINGW32__) || defined(__MINGW64__)
+  // Cannot rename a directory to an existing directory
+#else
+  // Can rename a non-empty directory to the name of an empty directory.
+  ec = bad_ec;
+  fs::rename(dir/"subdir2", dir/"subdir", ec);
+  VERIFY( !ec );
+  VERIFY( is_directory(dir/"subdir") );
+  VERIFY( !exists(dir/"subdir2") );
+  VERIFY( is_regular_file(dir/"subdir/file") );
+#endif
+
+  f2.path.clear();
+  f.path.clear();
+
+  fs::remove_all(dir, ec);
+}
+
+int
+main()
+{
+  test01();
+  test_symlinks();
+  test_directories();
+}
diff --git a/libstdc++-v3/testsuite/experimental/filesystem/operations/rename.cc b/libstdc++-v3/testsuite/experimental/filesystem/operations/rename.cc
new file mode 100644
index 00000000000..56039e7f37d
--- /dev/null
+++ b/libstdc++-v3/testsuite/experimental/filesystem/operations/rename.cc
@@ -0,0 +1,180 @@
+// Copyright (C) 2021 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-DUSE_FILESYSTEM_TS -lstdc++fs" }
+// { dg-do run { target c++11 } }
+// { dg-require-filesystem-ts "" }
+
+#include <experimental/filesystem>
+#include <testsuite_hooks.h>
+#include <testsuite_fs.h>
+
+namespace fs = std::experimental::filesystem;
+
+void
+test01()
+{
+  std::error_code ec;
+  const std::error_code bad_ec = make_error_code(std::errc::invalid_argument);
+
+  auto p1 = __gnu_test::nonexistent_path();
+  auto p2 = __gnu_test::nonexistent_path();
+
+  fs::rename(p1, p2, ec);
+  VERIFY( ec );
+
+  ec.clear();
+  fs::rename(p1, "", ec);
+  VERIFY( ec );
+
+  ec.clear();
+  fs::rename("", p1, ec);
+  VERIFY( ec );
+
+  ec = bad_ec;
+  std::ofstream{p1}; // create file
+  fs::rename(p1, p1, ec); // no-op
+  VERIFY( !ec );
+  VERIFY( is_regular_file(p1) );
+
+  ec.clear();
+  rename(p2, p1, ec);
+  VERIFY( ec );
+  VERIFY( is_regular_file(p1) );
+
+  ec = bad_ec;
+  fs::rename(p1, p2, ec);
+  VERIFY( !ec );
+  VERIFY( !exists(p1) );
+  VERIFY( is_regular_file(p2) );
+
+  ec = bad_ec;
+  std::ofstream{p1}; // create file
+  fs::rename(p1, p2, ec);
+  VERIFY( !ec );
+  VERIFY( !exists(p1) );
+  VERIFY( is_regular_file(p2) );
+
+  fs::remove(p2, ec);
+}
+
+void
+test_symlinks()
+{
+#if defined(__MINGW32__) || defined(__MINGW64__)
+  // No symlink support
+#else
+  std::error_code ec;
+  const std::error_code bad_ec = make_error_code(std::errc::invalid_argument);
+
+  const auto dir = __gnu_test::nonexistent_path();
+  fs::create_directory(dir);
+
+  create_symlink(dir/"nonesuch", dir/"link");  // dangling symlink
+  ec = bad_ec;
+  fs::rename(dir/"link", dir/"newlink", ec);
+  VERIFY( !ec );
+  VERIFY( !exists(symlink_status(dir/"link")) );
+  VERIFY( is_symlink(dir/"newlink") );
+
+  __gnu_test::scoped_file f(dir/"file");
+  create_symlink(dir/"file", dir/"link");
+  ec = bad_ec;
+  fs::rename(dir/"link", dir/"newerlink", ec);
+  VERIFY( !ec );
+  VERIFY( !exists(symlink_status(dir/"link")) );
+  VERIFY( is_symlink(dir/"newerlink") );
+  VERIFY( is_regular_file(dir/"file") );
+
+  fs::remove_all(dir, ec);
+  f.path.clear();
+#endif
+}
+
+void
+test_directories()
+{
+  std::error_code ec;
+  const std::error_code bad_ec = make_error_code(std::errc::invalid_argument);
+
+  const auto dir = __gnu_test::nonexistent_path();
+  fs::create_directory(dir);
+  __gnu_test::scoped_file f(dir/"file");
+  fs::create_directory(dir/"subdir");
+
+  // Rename directory.
+  ec = bad_ec;
+  fs::rename(dir/"subdir", dir/"subdir2", ec);
+  VERIFY( !ec );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( !exists(dir/"subdir") );
+
+  // Cannot rename a directory to a sub-directory of itself.
+  fs::rename(dir/"subdir2", dir/"subdir2/subsubdir", ec);
+  VERIFY( ec );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( !exists(dir/"subdir2"/"subsubdir") );
+
+  // Cannot rename a file to the name of an existing directory.
+  ec.clear();
+  fs::rename(dir/"file", dir/"subdir2", ec);
+  VERIFY( ec );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( is_regular_file(dir/"file") );
+
+#if defined(__MINGW32__) || defined(__MINGW64__)
+  // XXX broken on Windows, see PR 98985
+#else
+  // Cannot rename a directory to the name of an existing non-directory
+  ec.clear();
+  fs::rename(dir/"subdir2", dir/"file", ec);
+  VERIFY( ec );
+  VERIFY( is_regular_file(dir/"file") );
+  VERIFY( is_directory(dir/"subdir2") );
+
+  // Cannot rename directory to the name of a non-empty directory.
+  ec.clear();
+  __gnu_test::scoped_file f2(dir/"subdir2/file");
+  fs::create_directory(dir/"subdir");
+  fs::rename(dir/"subdir", dir/"subdir2", ec);
+  VERIFY( ec );
+  VERIFY( is_directory(dir/"subdir") );
+  VERIFY( is_directory(dir/"subdir2") );
+  VERIFY( is_regular_file(dir/"subdir2/file") );
+
+  // Can rename a non-empty directory to the name of an empty directory.
+  ec = bad_ec;
+  fs::rename(dir/"subdir2", dir/"subdir", ec);
+  VERIFY( !ec );
+  VERIFY( is_directory(dir/"subdir") );
+  VERIFY( !exists(dir/"subdir2") );
+  VERIFY( is_regular_file(dir/"subdir/file") );
+  f2.path.clear();
+
+  f.path.clear();
+#endif
+
+  fs::remove_all(dir, ec);
+}
+
+int
+main()
+{
+  test01();
+  test_symlinks();
+  test_directories();
+}

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