diff --git a/posix.cc b/posix.cc
new file mode 100644
index 00000000..9d883603
--- /dev/null
+++ b/posix.cc
@@ -0,0 +1,194 @@
+/*
+ A C++ interface to POSIX functions.
+
+ Copyright (c) 2014, Victor Zverovich
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+    list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "posix.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifndef _WIN32
+# include <unistd.h>
+#else
+# include <io.h>
+
+# define O_CREAT _O_CREAT
+# define O_TRUNC _O_TRUNC
+# define S_IRUSR _S_IREAD
+# define S_IWUSR _S_IWRITE
+
+#endif  // _WIN32
+
+// Retries the expression while it evaluates to -1 and error equals to EINTR.
+#ifndef _WIN32
+# define FMT_RETRY(result, expression) \
+  do { \
+    result = (expression); \
+  } while (result == -1 && errno == EINTR)
+#else
+# define FMT_RETRY(result, expression) result = (expression)
+#endif
+
+namespace {
+#ifdef _WIN32
+// On Windows the count argument to read and write is unsigned, so convert
+// it from size_t preventing integer overflow.
+inline unsigned ConvertRWCount(std::size_t count) {
+  return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
+}
+#else
+inline std::size_t ConvertRWCount(std::size_t count) { return count; }
+#endif
+}
+
+BufferedFile::~BufferedFile() FMT_NOEXCEPT(true) {
+  if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
+    fmt::ReportSystemError(errno, "cannot close file");
+}
+
+void BufferedFile::close() {
+  if (!file_)
+    return;
+  int result = FMT_SYSTEM(fclose(file_));
+  file_ = 0;
+  if (result != 0)
+    fmt::ThrowSystemError(errno, "cannot close file");
+}
+
+int BufferedFile::fileno() const {
+  int fd = FMT_POSIX_CALL(fileno(file_));
+  if (fd == -1)
+    fmt::ThrowSystemError(errno, "cannot get file descriptor");
+  return fd;
+}
+
+File::File(const char *path, int oflag) {
+  int mode = S_IRUSR | S_IWUSR;
+#ifdef _WIN32
+  fd_ = -1;
+  FMT_POSIX_CALL(sopen_s(&fd_, path, oflag, _SH_DENYNO, mode));
+#else
+  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path, oflag, mode)));
+#endif
+  if (fd_ == -1)
+    fmt::ThrowSystemError(errno, "cannot open file {}") << path;
+}
+
+File::~File() FMT_NOEXCEPT(true) {
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
+    fmt::ReportSystemError(errno, "cannot close file");
+}
+
+void File::close() {
+  if (fd_ == -1)
+    return;
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  int result = FMT_POSIX_CALL(close(fd_));
+  fd_ = -1;
+  if (result != 0)
+    fmt::ThrowSystemError(errno, "cannot close file");
+}
+
+std::streamsize File::read(void *buffer, std::size_t count) {
+  std::streamsize result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, ConvertRWCount(count))));
+  if (result == -1)
+    fmt::ThrowSystemError(errno, "cannot read from file");
+  return result;
+}
+
+std::streamsize File::write(const void *buffer, std::size_t count) {
+  std::streamsize result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, ConvertRWCount(count))));
+  if (result == -1)
+    fmt::ThrowSystemError(errno, "cannot write to file");
+  return result;
+}
+
+File File::dup(int fd) {
+  // Don't retry as dup doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
+  int new_fd = FMT_POSIX_CALL(dup(fd));
+  if (new_fd == -1)
+    fmt::ThrowSystemError(errno, "cannot duplicate file descriptor {}") << fd;
+  return File(new_fd);
+}
+
+void File::dup2(int fd) {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1) {
+    fmt::ThrowSystemError(errno,
+      "cannot duplicate file descriptor {} to {}") << fd_ << fd;
+  }
+}
+
+void File::dup2(int fd, ErrorCode &ec) FMT_NOEXCEPT(true) {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1)
+    ec = ErrorCode(errno);
+}
+
+void File::pipe(File &read_end, File &write_end) {
+  // Close the descriptors first to make sure that assignments don't throw
+  // and there are no leaks.
+  read_end.close();
+  write_end.close();
+  int fds[2] = {};
+#ifdef _WIN32
+  // Make the default pipe capacity same as on Linux 2.6.11+.
+  enum { DEFAULT_CAPACITY = 65536 };
+  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
+#else
+  // Don't retry as the pipe function doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
+  int result = FMT_POSIX_CALL(pipe(fds));
+#endif
+  if (result != 0)
+    fmt::ThrowSystemError(errno, "cannot create pipe");
+  // The following assignments don't throw because read_fd and write_fd
+  // are closed.
+  read_end = File(fds[0]);
+  write_end = File(fds[1]);
+}
+
+BufferedFile File::fdopen(const char *mode) {
+  // Don't retry as fdopen doesn't return EINTR.
+  FILE *f = FMT_POSIX_CALL(fdopen(fd_, mode));
+  if (!f) {
+    fmt::ThrowSystemError(errno,
+      "cannot associate stream with file descriptor");
+  }
+  BufferedFile file(f);
+  fd_ = -1;
+  return file;
+}
diff --git a/posix.h b/posix.h
new file mode 100644
index 00000000..ef495bb0
--- /dev/null
+++ b/posix.h
@@ -0,0 +1,284 @@
+/*
+ A C++ interface to POSIX functions.
+
+ Copyright (c) 2014, Victor Zverovich
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+    list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef FMT_POSIX_H
+#define FMT_POSIX_H
+
+#include <stdio.h>
+#include <fcntl.h>
+
+#include <cstddef>
+#include <ios>
+
+#ifndef FMT_POSIX
+# ifdef _WIN32
+// Fix warnings about deprecated symbols.
+#  define FMT_POSIX(call) _##call
+# else
+#  define FMT_POSIX(call) call
+# endif
+#endif
+
+// Calls to system functions are wrapped in FMT_SYSTEM for testability.
+#ifdef FMT_SYSTEM
+# define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
+#else
+# define FMT_SYSTEM(call) call
+# ifdef _WIN32
+// Fix warnings about deprecated symbols.
+#  define FMT_POSIX_CALL(call) ::_##call
+# else
+#  define FMT_POSIX_CALL(call) ::call
+# endif
+#endif
+
+// An error code.
+class ErrorCode {
+ private:
+  int value_;
+
+ public:
+  explicit ErrorCode(int value = 0) FMT_NOEXCEPT(true) : value_(value) {}
+
+  int get() const FMT_NOEXCEPT(true) { return value_; }
+};
+
+// A buffered file.
+class BufferedFile {
+ private:
+  FILE *file_;
+
+  friend class File;
+
+  explicit BufferedFile(FILE *f) : file_(f) {}
+
+ public:
+  // Constructs a BufferedFile object which doesn't represent any file.
+  BufferedFile() FMT_NOEXCEPT(true) : file_(0) {}
+
+  // Destroys the object closing the file it represents if any.
+  ~BufferedFile() FMT_NOEXCEPT(true);
+
+#if !FMT_USE_RVALUE_REFERENCES
+  // Emulate a move constructor and a move assignment operator if rvalue
+  // references are not supported.
+
+ private:
+  // A proxy object to emulate a move constructor.
+  // It is private to make it impossible call operator Proxy directly.
+  struct Proxy {
+    FILE *file;
+  };
+
+ public:
+  // A "move constructor" for moving from a temporary.
+  BufferedFile(Proxy p) FMT_NOEXCEPT(true) : file_(p.file) {}
+
+  // A "move constructor" for for moving from an lvalue.
+  BufferedFile(BufferedFile &f) FMT_NOEXCEPT(true) : file_(f.file_) {
+    f.file_ = 0;
+  }
+
+  // A "move assignment operator" for moving from a temporary.
+  BufferedFile &operator=(Proxy p) {
+    close();
+    file_ = p.file;
+    return *this;
+  }
+
+  // A "move assignment operator" for moving from an lvalue.
+  BufferedFile &operator=(BufferedFile &other) {
+    close();
+    file_ = other.file_;
+    other.file_ = 0;
+    return *this;
+  }
+
+  // Returns a proxy object for moving from a temporary:
+  //   BufferedFile file = BufferedFile(...);
+  operator Proxy() FMT_NOEXCEPT(true) {
+    Proxy p = {file_};
+    file_ = 0;
+    return p;
+  }
+#else
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(BufferedFile);
+
+ public:
+  BufferedFile(BufferedFile &&other) FMT_NOEXCEPT(true) : file_(other.file_) {
+    other.file_ = 0;
+  }
+
+  BufferedFile& operator=(BufferedFile &&other) {
+    close();
+    file_ = other.file_;
+    other.file_ = 0;
+    return *this;
+  }
+#endif
+
+  // Closes the file.
+  void close();
+
+  // Returns the pointer to a FILE object representing this file.
+  FILE *get() const { return file_; }
+
+  int fileno() const;
+};
+
+// A file. Closed file is represented by a File object with descriptor -1.
+// Methods that are not declared with FMT_NOEXCEPT(true) may throw
+// fmt::SystemError in case of failure. Note that some errors such as
+// closing the file multiple times will cause a crash on Windows rather
+// than an exception. You can get standard behavior by overriding the
+// invalid parameter handler with _set_invalid_parameter_handler.
+class File {
+ private:
+  int fd_;  // File descriptor.
+
+  // Constructs a File object with a given descriptor.
+  explicit File(int fd) : fd_(fd) {}
+
+ public:
+  // Possible values for the oflag argument to the constructor.
+  enum {
+    RDONLY = FMT_POSIX(O_RDONLY), // Open for reading only.
+    WRONLY = FMT_POSIX(O_WRONLY), // Open for writing only.
+    RDWR   = FMT_POSIX(O_RDWR)    // Open for reading and writing.
+  };
+
+  // Constructs a File object which doesn't represent any file.
+  File() FMT_NOEXCEPT(true) : fd_(-1) {}
+
+  // Opens a file and constructs a File object representing this file.
+  File(const char *path, int oflag);
+
+#if !FMT_USE_RVALUE_REFERENCES
+  // Emulate a move constructor and a move assignment operator if rvalue
+  // references are not supported.
+
+ private:
+  // A proxy object to emulate a move constructor.
+  // It is private to make it impossible call operator Proxy directly.
+  struct Proxy {
+    int fd;
+  };
+
+ public:
+  // A "move constructor" for moving from a temporary.
+  File(Proxy p) FMT_NOEXCEPT(true) : fd_(p.fd) {}
+
+  // A "move constructor" for for moving from an lvalue.
+  File(File &other) FMT_NOEXCEPT(true) : fd_(other.fd_) {
+    other.fd_ = -1;
+  }
+
+  // A "move assignment operator" for moving from a temporary.
+  File &operator=(Proxy p) {
+    close();
+    fd_ = p.fd;
+    return *this;
+  }
+
+  // A "move assignment operator" for moving from an lvalue.
+  File &operator=(File &other) {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+
+  // Returns a proxy object for moving from a temporary:
+  //   File file = File(...);
+  operator Proxy() FMT_NOEXCEPT(true) {
+    Proxy p = {fd_};
+    fd_ = -1;
+    return p;
+  }
+#else
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(File);
+
+ public:
+  File(File &&other) FMT_NOEXCEPT(true) : fd_(other.fd_) {
+    other.fd_ = -1;
+  }
+
+  File& operator=(File &&other) {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+#endif
+
+  // Destroys the object closing the file it represents if any.
+  ~File() FMT_NOEXCEPT(true);
+
+  // Returns the file descriptor.
+  int descriptor() const FMT_NOEXCEPT(true) { return fd_; }
+
+  // Closes the file.
+  void close();
+
+  // Attempts to read count bytes from the file into the specified buffer.
+  std::streamsize read(void *buffer, std::size_t count);
+
+  // Attempts to write count bytes from the specified buffer to the file.
+  std::streamsize write(const void *buffer, std::size_t count);
+
+  // Duplicates a file descriptor with the dup function and returns
+  // the duplicate as a file object.
+  static File dup(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd, ErrorCode &ec) FMT_NOEXCEPT(true);
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  static void pipe(File &read_end, File &write_end);
+
+  // Creates a BufferedFile object associated with this file and detaches
+  // this File object from the file.
+  BufferedFile fdopen(const char *mode);
+};
+
+#if !FMT_USE_RVALUE_REFERENCES
+namespace std {
+// For compatibility with C++98.
+inline BufferedFile &move(BufferedFile &f) { return f; }
+inline File &move(File &f) { return f; }
+}
+#endif
+
+#endif  // FMT_POSIX_H
diff --git a/test/gtest-extra.cc b/test/gtest-extra.cc
index 3e103afd..41a80a28 100644
--- a/test/gtest-extra.cc
+++ b/test/gtest-extra.cc
@@ -29,171 +29,7 @@
 
 #if FMT_USE_FILE_DESCRIPTORS
 
-#include <errno.h>
-#include <limits.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-
-#ifndef _WIN32
-# include <unistd.h>
-#else
-# include <io.h>
-
-# define O_CREAT _O_CREAT
-# define O_TRUNC _O_TRUNC
-# define S_IRUSR _S_IREAD
-# define S_IWUSR _S_IWRITE
-
-#endif  // _WIN32
-
-// Retries the expression while it evaluates to -1 and error equals to EINTR.
-#ifndef _WIN32
-# define FMT_RETRY(result, expression) \
-  do { \
-    result = (expression); \
-  } while (result == -1 && errno == EINTR)
-#else
-# define FMT_RETRY(result, expression) result = (expression)
-#endif
-
-namespace {
-#ifdef _WIN32
-// On Windows the count argument to read and write is unsigned, so convert
-// it from size_t preventing integer overflow.
-inline unsigned ConvertRWCount(std::size_t count) {
-  return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
-}
-#else
-inline std::size_t ConvertRWCount(std::size_t count) { return count; }
-#endif
-}
-
-BufferedFile::~BufferedFile() FMT_NOEXCEPT(true) {
-  if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
-    fmt::ReportSystemError(errno, "cannot close file");
-}
-
-void BufferedFile::close() {
-  if (!file_)
-    return;
-  int result = FMT_SYSTEM(fclose(file_));
-  file_ = 0;
-  if (result != 0)
-    fmt::ThrowSystemError(errno, "cannot close file");
-}
-
-int BufferedFile::fileno() const {
-  int fd = FMT_POSIX_CALL(fileno(file_));
-  if (fd == -1)
-    fmt::ThrowSystemError(errno, "cannot get file descriptor");
-  return fd;
-}
-
-File::File(const char *path, int oflag) {
-  int mode = S_IRUSR | S_IWUSR;
-#ifdef _WIN32
-  fd_ = -1;
-  FMT_POSIX_CALL(sopen_s(&fd_, path, oflag, _SH_DENYNO, mode));
-#else
-  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path, oflag, mode)));
-#endif
-  if (fd_ == -1)
-    fmt::ThrowSystemError(errno, "cannot open file {}") << path;
-}
-
-File::~File() FMT_NOEXCEPT(true) {
-  // Don't retry close in case of EINTR!
-  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
-  if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
-    fmt::ReportSystemError(errno, "cannot close file");
-}
-
-void File::close() {
-  if (fd_ == -1)
-    return;
-  // Don't retry close in case of EINTR!
-  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
-  int result = FMT_POSIX_CALL(close(fd_));
-  fd_ = -1;
-  if (result != 0)
-    fmt::ThrowSystemError(errno, "cannot close file");
-}
-
-std::streamsize File::read(void *buffer, std::size_t count) {
-  std::streamsize result = 0;
-  FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, ConvertRWCount(count))));
-  if (result == -1)
-    fmt::ThrowSystemError(errno, "cannot read from file");
-  return result;
-}
-
-std::streamsize File::write(const void *buffer, std::size_t count) {
-  std::streamsize result = 0;
-  FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, ConvertRWCount(count))));
-  if (result == -1)
-    fmt::ThrowSystemError(errno, "cannot write to file");
-  return result;
-}
-
-File File::dup(int fd) {
-  // Don't retry as dup doesn't return EINTR.
-  // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
-  int new_fd = FMT_POSIX_CALL(dup(fd));
-  if (new_fd == -1)
-    fmt::ThrowSystemError(errno, "cannot duplicate file descriptor {}") << fd;
-  return File(new_fd);
-}
-
-void File::dup2(int fd) {
-  int result = 0;
-  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
-  if (result == -1) {
-    fmt::ThrowSystemError(errno,
-        "cannot duplicate file descriptor {} to {}") << fd_ << fd;
-  }
-}
-
-void File::dup2(int fd, ErrorCode &ec) FMT_NOEXCEPT(true) {
-  int result = 0;
-  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
-  if (result == -1)
-    ec = ErrorCode(errno);
-}
-
-void File::pipe(File &read_end, File &write_end) {
-  // Close the descriptors first to make sure that assignments don't throw
-  // and there are no leaks.
-  read_end.close();
-  write_end.close();
-  int fds[2] = {};
-#ifdef _WIN32
-  // Make the default pipe capacity same as on Linux 2.6.11+.
-  enum { DEFAULT_CAPACITY = 65536 };
-  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
-#else
-  // Don't retry as the pipe function doesn't return EINTR.
-  // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
-  int result = FMT_POSIX_CALL(pipe(fds));
-#endif
-  if (result != 0)
-    fmt::ThrowSystemError(errno, "cannot create pipe");
-  // The following assignments don't throw because read_fd and write_fd
-  // are closed.
-  read_end = File(fds[0]);
-  write_end = File(fds[1]);
-}
-
-BufferedFile File::fdopen(const char *mode) {
-  // Don't retry as fdopen doesn't return EINTR.
-  FILE *f = FMT_POSIX_CALL(fdopen(fd_, mode));
-  if (!f) {
-    fmt::ThrowSystemError(errno,
-        "cannot associate stream with file descriptor");
-  }
-  BufferedFile file(f);
-  fd_ = -1;
-  return file;
-}
+#include "posix.cc"
 
 void OutputRedirect::Flush() {
 #if EOF != -1
diff --git a/test/gtest-extra.h b/test/gtest-extra.h
index 1c5e373d..3211c062 100644
--- a/test/gtest-extra.h
+++ b/test/gtest-extra.h
@@ -28,16 +28,8 @@
 #ifndef FMT_GTEST_EXTRA_H
 #define FMT_GTEST_EXTRA_H
 
-#include <cstddef>
-#include <ios>
 #include <string>
 
-#include <stdio.h>
-
-#if FMT_USE_FILE_DESCRIPTORS
-# include <fcntl.h>
-#endif
-
 #include <gtest/gtest.h>
 
 #include "format.h"
@@ -46,6 +38,14 @@
 # include "posix-test.h"
 #endif
 
+#ifndef FMT_USE_FILE_DESCRIPTORS
+# define FMT_USE_FILE_DESCRIPTORS 0
+#endif
+
+#if FMT_USE_FILE_DESCRIPTORS
+# include "posix.h"
+#endif
+
 #define FMT_TEST_THROW_(statement, expected_exception, expected_message, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
   if (::testing::AssertionResult gtest_ar = ::testing::AssertionSuccess()) { \
@@ -92,259 +92,8 @@ std::string FormatSystemErrorMessage(int error_code, fmt::StringRef message);
   EXPECT_THROW_MSG(statement, fmt::SystemError, \
       FormatSystemErrorMessage(error_code, message))
 
-#ifndef FMT_USE_FILE_DESCRIPTORS
-# define FMT_USE_FILE_DESCRIPTORS 0
-#endif
-
 #if FMT_USE_FILE_DESCRIPTORS
 
-#ifndef FMT_POSIX
-# ifdef _WIN32
-// Fix warnings about deprecated symbols.
-#  define FMT_POSIX(call) _##call
-# else
-#  define FMT_POSIX(call) call
-# endif
-#endif
-
-// Calls to system functions are wrapped in FMT_SYSTEM for testability.
-#ifdef FMT_SYSTEM
-# define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
-#else
-# define FMT_SYSTEM(call) call
-# ifdef _WIN32
-// Fix warnings about deprecated symbols.
-#  define FMT_POSIX_CALL(call) ::_##call
-# else
-#  define FMT_POSIX_CALL(call) ::call
-# endif
-#endif
-
-// An error code.
-class ErrorCode {
- private:
-  int value_;
-
- public:
-  explicit ErrorCode(int value = 0) FMT_NOEXCEPT(true) : value_(value) {}
-
-  int get() const FMT_NOEXCEPT(true) { return value_; }
-};
-
-// A buffered file.
-class BufferedFile {
- private:
-  FILE *file_;
-
-  friend class File;
-
-  explicit BufferedFile(FILE *f) : file_(f) {}
-
- public:
-  // Constructs a BufferedFile object which doesn't represent any file.
-  BufferedFile() FMT_NOEXCEPT(true) : file_(0) {}
-
-  // Destroys the object closing the file it represents if any.
-  ~BufferedFile() FMT_NOEXCEPT(true);
-
-#if !FMT_USE_RVALUE_REFERENCES
-  // Emulate a move constructor and a move assignment operator if rvalue
-  // references are not supported.
-
- private:
-  // A proxy object to emulate a move constructor.
-  // It is private to make it impossible call operator Proxy directly.
-  struct Proxy {
-    FILE *file;
-  };
-
- public:
-  // A "move constructor" for moving from a temporary.
-  BufferedFile(Proxy p) FMT_NOEXCEPT(true) : file_(p.file) {}
-
-  // A "move constructor" for for moving from an lvalue.
-  BufferedFile(BufferedFile &f) FMT_NOEXCEPT(true) : file_(f.file_) {
-    f.file_ = 0;
-  }
-
-  // A "move assignment operator" for moving from a temporary.
-  BufferedFile &operator=(Proxy p) {
-    close();
-    file_ = p.file;
-    return *this;
-  }
-
-  // A "move assignment operator" for moving from an lvalue.
-  BufferedFile &operator=(BufferedFile &other) {
-    close();
-    file_ = other.file_;
-    other.file_ = 0;
-    return *this;
-  }
-
-  // Returns a proxy object for moving from a temporary:
-  //   BufferedFile file = BufferedFile(...);
-  operator Proxy() FMT_NOEXCEPT(true) {
-    Proxy p = {file_};
-    file_ = 0;
-    return p;
-  }
-#else
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(BufferedFile);
-
- public:
-  BufferedFile(BufferedFile &&other) FMT_NOEXCEPT(true) : file_(other.file_) {
-    other.file_ = 0;
-  }
-
-  BufferedFile& operator=(BufferedFile &&other) {
-    close();
-    file_ = other.file_;
-    other.file_ = 0;
-    return *this;
-  }
-#endif
-
-  // Closes the file.
-  void close();
-
-  // Returns the pointer to a FILE object representing this file.
-  FILE *get() const { return file_; }
-
-  int fileno() const;
-};
-
-// A file. Closed file is represented by a File object with descriptor -1.
-// Methods that are not declared with FMT_NOEXCEPT(true) may throw
-// fmt::SystemError in case of failure. Note that some errors such as
-// closing the file multiple times will cause a crash on Windows rather
-// than an exception. You can get standard behavior by overriding the
-// invalid parameter handler with _set_invalid_parameter_handler.
-class File {
- private:
-  int fd_;  // File descriptor.
-
-  // Constructs a File object with a given descriptor.
-  explicit File(int fd) : fd_(fd) {}
-
- public:
-  // Possible values for the oflag argument to the constructor.
-  enum {
-    RDONLY = FMT_POSIX(O_RDONLY), // Open for reading only.
-    WRONLY = FMT_POSIX(O_WRONLY), // Open for writing only.
-    RDWR   = FMT_POSIX(O_RDWR)    // Open for reading and writing.
-  };
-
-  // Constructs a File object which doesn't represent any file.
-  File() FMT_NOEXCEPT(true) : fd_(-1) {}
-
-  // Opens a file and constructs a File object representing this file.
-  File(const char *path, int oflag);
-
-#if !FMT_USE_RVALUE_REFERENCES
-  // Emulate a move constructor and a move assignment operator if rvalue
-  // references are not supported.
-
- private:
-  // A proxy object to emulate a move constructor.
-  // It is private to make it impossible call operator Proxy directly.
-  struct Proxy {
-    int fd;
-  };
-
- public:
-  // A "move constructor" for moving from a temporary.
-  File(Proxy p) FMT_NOEXCEPT(true) : fd_(p.fd) {}
-
-  // A "move constructor" for for moving from an lvalue.
-  File(File &other) FMT_NOEXCEPT(true) : fd_(other.fd_) {
-    other.fd_ = -1;
-  }
-
-  // A "move assignment operator" for moving from a temporary.
-  File &operator=(Proxy p) {
-    close();
-    fd_ = p.fd;
-    return *this;
-  }
-
-  // A "move assignment operator" for moving from an lvalue.
-  File &operator=(File &other) {
-    close();
-    fd_ = other.fd_;
-    other.fd_ = -1;
-    return *this;
-  }
-
-  // Returns a proxy object for moving from a temporary:
-  //   File file = File(...);
-  operator Proxy() FMT_NOEXCEPT(true) {
-    Proxy p = {fd_};
-    fd_ = -1;
-    return p;
-  }
-#else
- private:
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(File);
-
- public:
-  File(File &&other) FMT_NOEXCEPT(true) : fd_(other.fd_) {
-    other.fd_ = -1;
-  }
-
-  File& operator=(File &&other) {
-    close();
-    fd_ = other.fd_;
-    other.fd_ = -1;
-    return *this;
-  }
-#endif
-
-  // Destroys the object closing the file it represents if any.
-  ~File() FMT_NOEXCEPT(true);
-
-  // Returns the file descriptor.
-  int descriptor() const FMT_NOEXCEPT(true) { return fd_; }
-
-  // Closes the file.
-  void close();
-
-  // Attempts to read count bytes from the file into the specified buffer.
-  std::streamsize read(void *buffer, std::size_t count);
-
-  // Attempts to write count bytes from the specified buffer to the file.
-  std::streamsize write(const void *buffer, std::size_t count);
-
-  // Duplicates a file descriptor with the dup function and returns
-  // the duplicate as a file object.
-  static File dup(int fd);
-
-  // Makes fd be the copy of this file descriptor, closing fd first if
-  // necessary.
-  void dup2(int fd);
-
-  // Makes fd be the copy of this file descriptor, closing fd first if
-  // necessary.
-  void dup2(int fd, ErrorCode &ec) FMT_NOEXCEPT(true);
-
-  // Creates a pipe setting up read_end and write_end file objects for reading
-  // and writing respectively.
-  static void pipe(File &read_end, File &write_end);
-
-  // Creates a BufferedFile object associated with this file and detaches
-  // this File object from the file.
-  BufferedFile fdopen(const char *mode);
-};
-
-#if !FMT_USE_RVALUE_REFERENCES
-namespace std {
-// For compatibility with C++98.
-inline BufferedFile &move(BufferedFile &f) { return f; }
-inline File &move(File &f) { return f; }
-}
-#endif
-
 // Captures file output by redirecting it to a pipe.
 // The output it can handle is limited by the pipe capacity.
 class OutputRedirect {