diff --git a/libcxx/src/filesystem/error.h b/libcxx/src/filesystem/error.h
--- a/libcxx/src/filesystem/error.h
+++ b/libcxx/src/filesystem/error.h
@@ -28,20 +28,13 @@
 # include <windows.h> // ERROR_* macros
 #endif
 
-// TODO: Check whether these functions actually need internal linkage, or if they can be made normal header functions
-_LIBCPP_DIAGNOSTIC_PUSH
-_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-template")
-
 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
 
 namespace detail {
-namespace {
 
 #if defined(_LIBCPP_WIN32API)
 
-errc __win_err_to_errc(int err) {
+inline errc __win_err_to_errc(int err) {
   constexpr struct {
     DWORD win;
     errc errc;
@@ -105,13 +98,13 @@
 
 #endif // _LIBCPP_WIN32API
 
-error_code capture_errno() {
+inline error_code capture_errno() {
   _LIBCPP_ASSERT(errno != 0, "Expected errno to be non-zero");
   return error_code(errno, generic_category());
 }
 
 #if defined(_LIBCPP_WIN32API)
-error_code make_windows_error(int err) {
+inline error_code make_windows_error(int err) {
   return make_error_code(__win_err_to_errc(err));
 }
 #endif
@@ -119,27 +112,27 @@
 template <class T>
 T error_value();
 template <>
-_LIBCPP_CONSTEXPR_SINCE_CXX14 void error_value<void>() {}
+inline _LIBCPP_CONSTEXPR_SINCE_CXX14 void error_value<void>() {}
 template <>
-bool error_value<bool>() {
+inline bool error_value<bool>() {
   return false;
 }
 #if __SIZEOF_SIZE_T__ != __SIZEOF_LONG_LONG__
 template <>
-size_t error_value<size_t>() {
+inline size_t error_value<size_t>() {
   return size_t(-1);
 }
 #endif
 template <>
-uintmax_t error_value<uintmax_t>() {
+inline uintmax_t error_value<uintmax_t>() {
   return uintmax_t(-1);
 }
 template <>
-_LIBCPP_CONSTEXPR_SINCE_CXX14 file_time_type error_value<file_time_type>() {
+inline _LIBCPP_CONSTEXPR_SINCE_CXX14 file_time_type error_value<file_time_type>() {
   return file_time_type::min();
 }
 template <>
-path error_value<path>() {
+inline path error_value<path>() {
   return {};
 }
 
@@ -238,7 +231,6 @@
   ErrorHandler& operator=(ErrorHandler const&) = delete;
 };
 
-} // end anonymous namespace
 } // end namespace detail
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
diff --git a/libcxx/src/filesystem/file_descriptor.h b/libcxx/src/filesystem/file_descriptor.h
--- a/libcxx/src/filesystem/file_descriptor.h
+++ b/libcxx/src/filesystem/file_descriptor.h
@@ -31,22 +31,15 @@
 # include <unistd.h>
 #endif // defined(_LIBCPP_WIN32API)
 
-// TODO: Check whether these functions actually need internal linkage, or if they can be made normal header functions
-_LIBCPP_DIAGNOSTIC_PUSH
-_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-template")
-
 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
 
 namespace detail {
-namespace {
 
 #if !defined(_LIBCPP_WIN32API)
 
 #if defined(DT_BLK)
 template <class DirEntT, class = decltype(DirEntT::d_type)>
-static file_type get_file_type(DirEntT* ent, int) {
+file_type get_file_type(DirEntT* ent, int) {
   switch (ent->d_type) {
   case DT_BLK:
     return file_type::block;
@@ -73,11 +66,11 @@
 #endif // defined(DT_BLK)
 
 template <class DirEntT>
-static file_type get_file_type(DirEntT*, long) {
+file_type get_file_type(DirEntT*, long) {
   return file_type::none;
 }
 
-static pair<string_view, file_type> posix_readdir(DIR* dir_stream,
+inline pair<string_view, file_type> posix_readdir(DIR* dir_stream,
                                                   error_code& ec) {
   struct dirent* dir_entry_ptr = nullptr;
   errno = 0; // zero errno in order to detect errors
@@ -93,7 +86,7 @@
 
 #else // _LIBCPP_WIN32API
 
-static file_type get_file_type(const WIN32_FIND_DATAW& data) {
+inline file_type get_file_type(const WIN32_FIND_DATAW& data) {
   if (data.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT &&
       data.dwReserved0 == IO_REPARSE_TAG_SYMLINK)
     return file_type::symlink;
@@ -101,10 +94,10 @@
     return file_type::directory;
   return file_type::regular;
 }
-static uintmax_t get_file_size(const WIN32_FIND_DATAW& data) {
+inline uintmax_t get_file_size(const WIN32_FIND_DATAW& data) {
   return (static_cast<uint64_t>(data.nFileSizeHigh) << 32) + data.nFileSizeLow;
 }
-static file_time_type get_write_time(const WIN32_FIND_DATAW& data) {
+inline file_time_type get_write_time(const WIN32_FIND_DATAW& data) {
   ULARGE_INTEGER tmp;
   const FILETIME& time = data.ftLastWriteTime;
   tmp.u.LowPart = time.dwLowDateTime;
@@ -175,12 +168,12 @@
   explicit FileDescriptor(const path* p, int descriptor = -1) : name(*p), fd(descriptor) {}
 };
 
-perms posix_get_perms(const StatT& st) noexcept {
+inline perms posix_get_perms(const StatT& st) noexcept {
   return static_cast<perms>(st.st_mode) & perms::mask;
 }
 
-file_status create_file_status(error_code& m_ec, path const& p,
-                               const StatT& path_stat, error_code* ec) {
+inline file_status create_file_status(error_code& m_ec, path const& p,
+                                      const StatT& path_stat, error_code* ec) {
   if (ec)
     *ec = m_ec;
   if (m_ec && (m_ec.value() == ENOENT || m_ec.value() == ENOTDIR)) {
@@ -215,32 +208,32 @@
   return fs_tmp;
 }
 
-file_status posix_stat(path const& p, StatT& path_stat, error_code* ec) {
+inline file_status posix_stat(path const& p, StatT& path_stat, error_code* ec) {
   error_code m_ec;
   if (detail::stat(p.c_str(), &path_stat) == -1)
     m_ec = detail::capture_errno();
   return create_file_status(m_ec, p, path_stat, ec);
 }
 
-file_status posix_stat(path const& p, error_code* ec) {
+inline file_status posix_stat(path const& p, error_code* ec) {
   StatT path_stat;
   return posix_stat(p, path_stat, ec);
 }
 
-file_status posix_lstat(path const& p, StatT& path_stat, error_code* ec) {
+inline file_status posix_lstat(path const& p, StatT& path_stat, error_code* ec) {
   error_code m_ec;
   if (detail::lstat(p.c_str(), &path_stat) == -1)
     m_ec = detail::capture_errno();
   return create_file_status(m_ec, p, path_stat, ec);
 }
 
-file_status posix_lstat(path const& p, error_code* ec) {
+inline file_status posix_lstat(path const& p, error_code* ec) {
   StatT path_stat;
   return posix_lstat(p, path_stat, ec);
 }
 
 // http://pubs.opengroup.org/onlinepubs/9699919799/functions/ftruncate.html
-bool posix_ftruncate(const FileDescriptor& fd, off_t to_size, error_code& ec) {
+inline bool posix_ftruncate(const FileDescriptor& fd, off_t to_size, error_code& ec) {
   if (detail::ftruncate(fd.fd, to_size) == -1) {
     ec = capture_errno();
     return true;
@@ -249,7 +242,7 @@
   return false;
 }
 
-bool posix_fchmod(const FileDescriptor& fd, const StatT& st, error_code& ec) {
+inline bool posix_fchmod(const FileDescriptor& fd, const StatT& st, error_code& ec) {
   if (detail::fchmod(fd.fd, st.st_mode) == -1) {
     ec = capture_errno();
     return true;
@@ -258,11 +251,11 @@
   return false;
 }
 
-bool stat_equivalent(const StatT& st1, const StatT& st2) {
+inline bool stat_equivalent(const StatT& st1, const StatT& st2) {
   return (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
 }
 
-file_status FileDescriptor::refresh_status(error_code& ec) {
+inline file_status FileDescriptor::refresh_status(error_code& ec) {
   // FD must be open and good.
   m_status = file_status{};
   m_stat = {};
@@ -273,11 +266,8 @@
   return m_status;
 }
 
-} // namespace
 } // end namespace detail
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
-_LIBCPP_DIAGNOSTIC_POP
-
 #endif // FILESYSTEM_FILE_DESCRIPTOR_H
diff --git a/libcxx/src/filesystem/format_string.h b/libcxx/src/filesystem/format_string.h
--- a/libcxx/src/filesystem/format_string.h
+++ b/libcxx/src/filesystem/format_string.h
@@ -25,19 +25,11 @@
 #  define PATH_CSTR_FMT "\"%s\""
 #endif
 
-// TODO: Check whether these functions actually need internal linkage, or if they can be made normal header functions
-_LIBCPP_DIAGNOSTIC_PUSH
-_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-template")
-
 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
 
 namespace detail {
-namespace {
 
-_LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 0)
-string vformat_string(const char* msg, va_list ap) {
+inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 0) string vformat_string(const char* msg, va_list ap) {
   array<char, 256> buf;
 
   va_list apcopy;
@@ -60,8 +52,7 @@
   return result;
 }
 
-_LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 2)
-string format_string(const char* msg, ...) {
+inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 2) string format_string(const char* msg, ...) {
   string ret;
   va_list ap;
   va_start(ap, msg);
@@ -79,11 +70,8 @@
   return ret;
 }
 
-} // end anonymous namespace
 } // end namespace detail
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
-_LIBCPP_DIAGNOSTIC_POP
-
 #endif // FILESYSTEM_FORMAT_STRING_H
diff --git a/libcxx/src/filesystem/operations.cpp b/libcxx/src/filesystem/operations.cpp
--- a/libcxx/src/filesystem/operations.cpp
+++ b/libcxx/src/filesystem/operations.cpp
@@ -350,7 +350,7 @@
       return err.report(m_ec);
   }
 
-  if (!copy_file_impl(from_fd, to_fd, m_ec)) {
+  if (!detail::copy_file_impl(from_fd, to_fd, m_ec)) {
     // FIXME: Remove the dest file if we failed, and it didn't exist previously.
     return err.report(m_ec);
   }
diff --git a/libcxx/src/filesystem/path_parser.h b/libcxx/src/filesystem/path_parser.h
--- a/libcxx/src/filesystem/path_parser.h
+++ b/libcxx/src/filesystem/path_parser.h
@@ -17,17 +17,9 @@
 
 #include "format_string.h"
 
-// TODO: Check whether these functions actually need internal linkage, or if they can be made normal header functions
-_LIBCPP_DIAGNOSTIC_PUSH
-_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-template")
-
 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
 
-namespace {
-
-bool isSeparator(path::value_type C) {
+inline bool isSeparator(path::value_type C) {
   if (C == '/')
     return true;
 #if defined(_LIBCPP_WIN32API)
@@ -37,7 +29,7 @@
   return false;
 }
 
-bool isDriveLetter(path::value_type C) {
+inline bool isDriveLetter(path::value_type C) {
   return (C >= 'a' && C <= 'z') || (C >= 'A' && C <= 'Z');
 }
 
@@ -356,7 +348,7 @@
   }
 };
 
-string_view_pair separate_filename(string_view_t const& s) {
+inline string_view_pair separate_filename(string_view_t const& s) {
   if (s == PATHSTR(".") || s == PATHSTR("..") || s.empty())
     return string_view_pair{s, PATHSTR("")};
   auto pos = s.find_last_of('.');
@@ -365,15 +357,12 @@
   return string_view_pair{s.substr(0, pos), s.substr(pos)};
 }
 
-string_view_t createView(PosPtr S, PosPtr E) noexcept {
+inline string_view_t createView(PosPtr S, PosPtr E) noexcept {
   return {S, static_cast<size_t>(E - S) + 1};
 }
 
 } // namespace parser
-} // namespace
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
-_LIBCPP_DIAGNOSTIC_POP
-
 #endif // PATH_PARSER_H
diff --git a/libcxx/src/filesystem/posix_compat.h b/libcxx/src/filesystem/posix_compat.h
--- a/libcxx/src/filesystem/posix_compat.h
+++ b/libcxx/src/filesystem/posix_compat.h
@@ -75,16 +75,9 @@
 };
 #endif
 
-// TODO: Check whether these functions actually need internal linkage, or if they can be made normal header functions
-_LIBCPP_DIAGNOSTIC_PUSH
-_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-template")
-
 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
 
 namespace detail {
-namespace {
 
 #if defined(_LIBCPP_WIN32API)
 // Various C runtime versions (UCRT, or the legacy msvcrt.dll used by
@@ -168,21 +161,21 @@
 // (1601) to the Unix epoch (1970).
 #define FILE_TIME_OFFSET_SECS (uint64_t(369 * 365 + 89) * (24 * 60 * 60))
 
-TimeSpec filetime_to_timespec(LARGE_INTEGER li) {
+inline TimeSpec filetime_to_timespec(LARGE_INTEGER li) {
   TimeSpec ret;
   ret.tv_sec = li.QuadPart / 10000000 - FILE_TIME_OFFSET_SECS;
   ret.tv_nsec = (li.QuadPart % 10000000) * 100;
   return ret;
 }
 
-TimeSpec filetime_to_timespec(FILETIME ft) {
+inline TimeSpec filetime_to_timespec(FILETIME ft) {
   LARGE_INTEGER li;
   li.LowPart = ft.dwLowDateTime;
   li.HighPart = ft.dwHighDateTime;
   return filetime_to_timespec(li);
 }
 
-FILETIME timespec_to_filetime(TimeSpec ts) {
+inline FILETIME timespec_to_filetime(TimeSpec ts) {
   LARGE_INTEGER li;
   li.QuadPart =
       ts.tv_nsec / 100 + (ts.tv_sec + FILE_TIME_OFFSET_SECS) * 10000000;
@@ -192,7 +185,7 @@
   return ft;
 }
 
-int set_errno(int e = GetLastError()) {
+inline int set_errno(int e = GetLastError()) {
   errno = static_cast<int>(__win_err_to_errc(e));
   return -1;
 }
@@ -215,7 +208,7 @@
   HANDLE h;
 };
 
-int stat_handle(HANDLE h, StatT *buf) {
+inline int stat_handle(HANDLE h, StatT *buf) {
   FILE_BASIC_INFO basic;
   if (!GetFileInformationByHandleEx(h, FileBasicInfo, &basic, sizeof(basic)))
     return set_errno();
@@ -253,7 +246,7 @@
   return 0;
 }
 
-int stat_file(const wchar_t *path, StatT *buf, DWORD flags) {
+inline int stat_file(const wchar_t *path, StatT *buf, DWORD flags) {
   WinHandle h(path, FILE_READ_ATTRIBUTES, flags);
   if (!h)
     return set_errno();
@@ -261,24 +254,24 @@
   return ret;
 }
 
-int stat(const wchar_t *path, StatT *buf) { return stat_file(path, buf, 0); }
+inline int stat(const wchar_t *path, StatT *buf) { return stat_file(path, buf, 0); }
 
-int lstat(const wchar_t *path, StatT *buf) {
+inline int lstat(const wchar_t *path, StatT *buf) {
   return stat_file(path, buf, FILE_FLAG_OPEN_REPARSE_POINT);
 }
 
-int fstat(int fd, StatT *buf) {
+inline int fstat(int fd, StatT *buf) {
   HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
   return stat_handle(h, buf);
 }
 
-int mkdir(const wchar_t *path, int permissions) {
+inline int mkdir(const wchar_t *path, int permissions) {
   (void)permissions;
   return _wmkdir(path);
 }
 
-int symlink_file_dir(const wchar_t *oldname, const wchar_t *newname,
-                     bool is_dir) {
+inline int symlink_file_dir(const wchar_t *oldname, const wchar_t *newname,
+                            bool is_dir) {
   path dest(oldname);
   dest.make_preferred();
   oldname = dest.c_str();
@@ -294,21 +287,21 @@
   return set_errno();
 }
 
-int symlink_file(const wchar_t *oldname, const wchar_t *newname) {
+inline int symlink_file(const wchar_t *oldname, const wchar_t *newname) {
   return symlink_file_dir(oldname, newname, false);
 }
 
-int symlink_dir(const wchar_t *oldname, const wchar_t *newname) {
+inline int symlink_dir(const wchar_t *oldname, const wchar_t *newname) {
   return symlink_file_dir(oldname, newname, true);
 }
 
-int link(const wchar_t *oldname, const wchar_t *newname) {
+inline int link(const wchar_t *oldname, const wchar_t *newname) {
   if (CreateHardLinkW(newname, oldname, nullptr))
     return 0;
   return set_errno();
 }
 
-int remove(const wchar_t *path) {
+inline int remove(const wchar_t *path) {
   detail::WinHandle h(path, DELETE, FILE_FLAG_OPEN_REPARSE_POINT);
   if (!h)
     return set_errno();
@@ -319,7 +312,7 @@
   return 0;
 }
 
-int truncate_handle(HANDLE h, off_t length) {
+inline int truncate_handle(HANDLE h, off_t length) {
   LARGE_INTEGER size_param;
   size_param.QuadPart = length;
   if (!SetFilePointerEx(h, size_param, 0, FILE_BEGIN))
@@ -329,19 +322,19 @@
   return 0;
 }
 
-int ftruncate(int fd, off_t length) {
+inline int ftruncate(int fd, off_t length) {
   HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
   return truncate_handle(h, length);
 }
 
-int truncate(const wchar_t *path, off_t length) {
+inline int truncate(const wchar_t *path, off_t length) {
   detail::WinHandle h(path, GENERIC_WRITE, 0);
   if (!h)
     return set_errno();
   return truncate_handle(h, length);
 }
 
-int rename(const wchar_t *from, const wchar_t *to) {
+inline int rename(const wchar_t *from, const wchar_t *to) {
   if (!(MoveFileExW(from, to,
                     MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING |
                         MOVEFILE_WRITE_THROUGH)))
@@ -352,8 +345,8 @@
 template <class... Args> int open(const wchar_t *filename, Args... args) {
   return _wopen(filename, args...);
 }
-int close(int fd) { return _close(fd); }
-int chdir(const wchar_t *path) { return _wchdir(path); }
+inline int close(int fd) { return _close(fd); }
+inline int chdir(const wchar_t *path) { return _wchdir(path); }
 
 struct StatVFS {
   uint64_t f_frsize;
@@ -362,7 +355,7 @@
   uint64_t f_bavail;
 };
 
-int statvfs(const wchar_t *p, StatVFS *buf) {
+inline int statvfs(const wchar_t *p, StatVFS *buf) {
   path dir = p;
   while (true) {
     error_code local_ec;
@@ -388,9 +381,9 @@
   return 0;
 }
 
-wchar_t *getcwd(wchar_t *buff, size_t size) { return _wgetcwd(buff, size); }
+inline wchar_t *getcwd(wchar_t *buff, size_t size) { return _wgetcwd(buff, size); }
 
-wchar_t *realpath(const wchar_t *path, wchar_t *resolved_name) {
+inline wchar_t *realpath(const wchar_t *path, wchar_t *resolved_name) {
   // Only expected to be used with us allocating the buffer.
   _LIBCPP_ASSERT(resolved_name == nullptr,
                  "Windows realpath() assumes a null resolved_name");
@@ -431,7 +424,7 @@
 #define AT_SYMLINK_NOFOLLOW 1
 using ModeT = int;
 
-int fchmod_handle(HANDLE h, int perms) {
+inline int fchmod_handle(HANDLE h, int perms) {
   FILE_BASIC_INFO basic;
   if (!GetFileInformationByHandleEx(h, FileBasicInfo, &basic, sizeof(basic)))
     return set_errno();
@@ -445,7 +438,7 @@
   return 0;
 }
 
-int fchmodat(int /*fd*/, const wchar_t *path, int perms, int flag) {
+inline int fchmodat(int /*fd*/, const wchar_t *path, int perms, int flag) {
   DWORD attributes = GetFileAttributesW(path);
   if (attributes == INVALID_FILE_ATTRIBUTES)
     return set_errno();
@@ -472,7 +465,7 @@
   return 0;
 }
 
-int fchmod(int fd, int perms) {
+inline int fchmod(int fd, int perms) {
   HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
   return fchmod_handle(h, perms);
 }
@@ -480,7 +473,7 @@
 #define MAX_SYMLINK_SIZE MAXIMUM_REPARSE_DATA_BUFFER_SIZE
 using SSizeT = ::int64_t;
 
-SSizeT readlink(const wchar_t *path, wchar_t *ret_buf, size_t bufsize) {
+inline SSizeT readlink(const wchar_t *path, wchar_t *ret_buf, size_t bufsize) {
   uint8_t buf[MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
   detail::WinHandle h(path, FILE_READ_ATTRIBUTES, FILE_FLAG_OPEN_REPARSE_POINT);
   if (!h)
@@ -524,10 +517,10 @@
 }
 
 #else
-int symlink_file(const char *oldname, const char *newname) {
+inline int symlink_file(const char *oldname, const char *newname) {
   return ::symlink(oldname, newname);
 }
-int symlink_dir(const char *oldname, const char *newname) {
+inline int symlink_dir(const char *oldname, const char *newname) {
   return ::symlink(oldname, newname);
 }
 using ::chdir;
@@ -559,11 +552,8 @@
 
 #endif
 
-} // namespace
 } // end namespace detail
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
-_LIBCPP_DIAGNOSTIC_POP
-
 #endif // POSIX_COMPAT_H
diff --git a/libcxx/src/filesystem/time_utils.h b/libcxx/src/filesystem/time_utils.h
--- a/libcxx/src/filesystem/time_utils.h
+++ b/libcxx/src/filesystem/time_utils.h
@@ -36,16 +36,9 @@
 # define _LIBCPP_USE_UTIMENSAT
 #endif
 
-// TODO: Check whether these functions actually need internal linkage, or if they can be made normal header functions
-_LIBCPP_DIAGNOSTIC_PUSH
-_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-function")
-_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-template")
-
 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
 
 namespace detail {
-namespace {
 
 using chrono::duration;
 using chrono::duration_cast;
@@ -284,8 +277,8 @@
 }
 
 #if defined(_LIBCPP_USE_UTIMENSAT)
-bool posix_utimensat(const path& p, std::array<TimeSpec, 2> const& TS,
-                     error_code& ec) {
+inline bool posix_utimensat(const path& p, std::array<TimeSpec, 2> const& TS,
+                            error_code& ec) {
   if (::utimensat(AT_FDCWD, p.c_str(), TS.data(), 0) == -1) {
     ec = capture_errno();
     return true;
@@ -294,8 +287,8 @@
 }
 #endif
 
-bool set_file_times(const path& p, std::array<TimeSpec, 2> const& TS,
-                    error_code& ec) {
+inline bool set_file_times(const path& p, std::array<TimeSpec, 2> const& TS,
+                           error_code& ec) {
 #if !defined(_LIBCPP_USE_UTIMENSAT)
   return posix_utimes(p, TS, ec);
 #else
@@ -305,8 +298,8 @@
 
 #endif // !_LIBCPP_WIN32API
 
-file_time_type __extract_last_write_time(const path& p, const StatT& st,
-                                         error_code* ec) {
+inline file_time_type __extract_last_write_time(const path& p, const StatT& st,
+                                                error_code* ec) {
   using detail::fs_time;
   ErrorHandler<file_time_type> err("last_write_time", ec, &p);
 
@@ -317,11 +310,8 @@
   return fs_time::convert_from_timespec(ts);
 }
 
-} // namespace
 } // end namespace detail
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
-_LIBCPP_DIAGNOSTIC_POP
-
 #endif // FILESYSTEM_TIME_UTILS_H