diff --git a/.clang-format b/.clang-format
index 6536f034e3..5df61b0661 100644
--- a/.clang-format
+++ b/.clang-format
@@ -1,5 +1,5 @@
 Standard: Cpp11
-UseTab: ForIndentation
+UseTab: Always
 TabWidth: 1
 IndentWidth: 1 
 AccessModifierOffset: -1
@@ -7,7 +7,7 @@ PointerAlignment: Left
 NamespaceIndentation: All
 ColumnLimit: 0
 BreakBeforeBraces: Allman
-BreakConstructorInitializersBeforeComma: true
+BreakConstructorInitializersBeforeComma: false
 BreakBeforeBinaryOperators: false
 BreakBeforeTernaryOperators: false
 AlwaysBreakTemplateDeclarations: true
@@ -20,7 +20,7 @@ Cpp11BracedListStyle: true
 IndentCaseLabels: false
 SortIncludes: false
 ReflowComments: true
-AlignConsecutiveAssignments: true
+AlignConsecutiveAssignments: false
 AlignTrailingComments: true
 AlignAfterOpenBracket: false
 ConstructorInitializerAllOnOneLineOrOnePerLine: false
diff --git a/git-clang-format b/git-clang-format
new file mode 100644
index 0000000000..aa4e975b6b
--- /dev/null
+++ b/git-clang-format
@@ -0,0 +1,485 @@
+#!/usr/bin/env python
+#
+#===- git-clang-format - ClangFormat Git Integration ---------*- python -*--===#
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+#===------------------------------------------------------------------------===#
+
+r"""                                                                             
+clang-format git integration                                                     
+============================                                                     
+                                                                                 
+This file provides a clang-format integration for git. Put it somewhere in your  
+path and ensure that it is executable. Then, "git clang-format" will invoke      
+clang-format on the changes in current files or a specific commit.               
+                                                                                 
+For further details, run:                                                        
+git clang-format -h                                                              
+                                                                                 
+Requires Python 2.7                                                              
+"""               
+
+import argparse
+import collections
+import contextlib
+import errno
+import os
+import re
+import subprocess
+import sys
+
+usage = 'git clang-format [OPTIONS] [<commit>] [--] [<file>...]'
+
+desc = '''
+Run clang-format on all lines that differ between the working directory
+and <commit>, which defaults to HEAD.  Changes are only applied to the working
+directory.
+
+The following git-config settings set the default of the corresponding option:
+  clangFormat.binary
+  clangFormat.commit
+  clangFormat.extension
+  clangFormat.style
+'''
+
+# Name of the temporary index file in which save the output of clang-format.
+# This file is created within the .git directory.
+temp_index_basename = 'clang-format-index'
+
+
+Range = collections.namedtuple('Range', 'start, count')
+
+
+def main():
+  config = load_git_config()
+
+  # In order to keep '--' yet allow options after positionals, we need to
+  # check for '--' ourselves.  (Setting nargs='*' throws away the '--', while
+  # nargs=argparse.REMAINDER disallows options after positionals.)
+  argv = sys.argv[1:]
+  try:
+    idx = argv.index('--')
+  except ValueError:
+    dash_dash = []
+  else:
+    dash_dash = argv[idx:]
+    argv = argv[:idx]
+
+  default_extensions = ','.join([
+      # From clang/lib/Frontend/FrontendOptions.cpp, all lower case
+      'c', 'h',  # C
+      'm',  # ObjC
+      'mm',  # ObjC++
+      'cc', 'cp', 'cpp', 'c++', 'cxx', 'hpp',  # C++
+      # Other languages that clang-format supports
+      'proto', 'protodevel',  # Protocol Buffers
+      'js',  # JavaScript
+      'ts',  # TypeScript
+      ])
+
+  p = argparse.ArgumentParser(
+    usage=usage, formatter_class=argparse.RawDescriptionHelpFormatter,
+    description=desc)
+  p.add_argument('--binary',
+                 default=config.get('clangformat.binary', 'clang-format'),
+                 help='path to clang-format'),
+  p.add_argument('--commit',
+                 default=config.get('clangformat.commit', 'HEAD'),
+                 help='default commit to use if none is specified'),
+  p.add_argument('--diff', action='store_true',
+                 help='print a diff instead of applying the changes')
+  p.add_argument('--extensions',
+                 default=config.get('clangformat.extensions',
+                                    default_extensions),
+                 help=('comma-separated list of file extensions to format, '
+                       'excluding the period and case-insensitive')),
+  p.add_argument('-f', '--force', action='store_true',
+                 help='allow changes to unstaged files')
+  p.add_argument('-p', '--patch', action='store_true',
+                 help='select hunks interactively')
+  p.add_argument('-q', '--quiet', action='count', default=0,
+                 help='print less information')
+  p.add_argument('--style',
+                 default=config.get('clangformat.style', None),
+                 help='passed to clang-format'),
+  p.add_argument('-v', '--verbose', action='count', default=0,
+                 help='print extra information')
+  # We gather all the remaining positional arguments into 'args' since we need
+  # to use some heuristics to determine whether or not <commit> was present.
+  # However, to print pretty messages, we make use of metavar and help.
+  p.add_argument('args', nargs='*', metavar='<commit>',
+                 help='revision from which to compute the diff')
+  p.add_argument('ignored', nargs='*', metavar='<file>...',
+                 help='if specified, only consider differences in these files')
+  opts = p.parse_args(argv)
+
+  opts.verbose -= opts.quiet
+  del opts.quiet
+
+  commit, files = interpret_args(opts.args, dash_dash, opts.commit)
+  changed_lines = compute_diff_and_extract_lines(commit, files)
+  if opts.verbose >= 1:
+    ignored_files = set(changed_lines)
+  filter_by_extension(changed_lines, opts.extensions.lower().split(','))
+  if opts.verbose >= 1:
+    ignored_files.difference_update(changed_lines)
+    if ignored_files:
+      print 'Ignoring changes in the following files (wrong extension):'
+      for filename in ignored_files:
+        print '   ', filename
+    if changed_lines:
+      print 'Running clang-format on the following files:'
+      for filename in changed_lines:
+        print '   ', filename
+  if not changed_lines:
+    print 'no modified files to format'
+    return
+  # The computed diff outputs absolute paths, so we must cd before accessing
+  # those files.
+  cd_to_toplevel()
+  old_tree = create_tree_from_workdir(changed_lines)
+  new_tree = run_clang_format_and_save_to_tree(changed_lines,
+                                               binary=opts.binary,
+                                               style=opts.style)
+  if opts.verbose >= 1:
+    print 'old tree:', old_tree
+    print 'new tree:', new_tree
+  if old_tree == new_tree:
+    if opts.verbose >= 0:
+      print 'clang-format did not modify any files'
+  elif opts.diff:
+    print_diff(old_tree, new_tree)
+  else:
+    changed_files = apply_changes(old_tree, new_tree, force=opts.force,
+                                  patch_mode=opts.patch)
+    if (opts.verbose >= 0 and not opts.patch) or opts.verbose >= 1:
+      print 'changed files:'
+      for filename in changed_files:
+        print '   ', filename
+
+
+def load_git_config(non_string_options=None):
+  """Return the git configuration as a dictionary.
+
+  All options are assumed to be strings unless in `non_string_options`, in which
+  is a dictionary mapping option name (in lower case) to either "--bool" or
+  "--int"."""
+  if non_string_options is None:
+    non_string_options = {}
+  out = {}
+  for entry in run('git', 'config', '--list', '--null').split('\0'):
+    if entry:
+      name, value = entry.split('\n', 1)
+      if name in non_string_options:
+        value = run('git', 'config', non_string_options[name], name)
+      out[name] = value
+  return out
+
+
+def interpret_args(args, dash_dash, default_commit):
+  """Interpret `args` as "[commit] [--] [files...]" and return (commit, files).
+
+  It is assumed that "--" and everything that follows has been removed from
+  args and placed in `dash_dash`.
+
+  If "--" is present (i.e., `dash_dash` is non-empty), the argument to its
+  left (if present) is taken as commit.  Otherwise, the first argument is
+  checked if it is a commit or a file.  If commit is not given,
+  `default_commit` is used."""
+  if dash_dash:
+    if len(args) == 0:
+      commit = default_commit
+    elif len(args) > 1:
+      die('at most one commit allowed; %d given' % len(args))
+    else:
+      commit = args[0]
+    object_type = get_object_type(commit)
+    if object_type not in ('commit', 'tag'):
+      if object_type is None:
+        die("'%s' is not a commit" % commit)
+      else:
+        die("'%s' is a %s, but a commit was expected" % (commit, object_type))
+    files = dash_dash[1:]
+  elif args:
+    if disambiguate_revision(args[0]):
+      commit = args[0]
+      files = args[1:]
+    else:
+      commit = default_commit
+      files = args
+  else:
+    commit = default_commit
+    files = []
+  return commit, files
+
+
+def disambiguate_revision(value):
+  """Returns True if `value` is a revision, False if it is a file, or dies."""
+  # If `value` is ambiguous (neither a commit nor a file), the following
+  # command will die with an appropriate error message.
+  run('git', 'rev-parse', value, verbose=False)
+  object_type = get_object_type(value)
+  if object_type is None:
+    return False
+  if object_type in ('commit', 'tag'):
+    return True
+  die('`%s` is a %s, but a commit or filename was expected' %
+      (value, object_type))
+
+
+def get_object_type(value):
+  """Returns a string description of an object's type, or None if it is not
+  a valid git object."""
+  cmd = ['git', 'cat-file', '-t', value]
+  p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+  stdout, stderr = p.communicate()
+  if p.returncode != 0:
+    return None
+  return stdout.strip()
+
+
+def compute_diff_and_extract_lines(commit, files):
+  """Calls compute_diff() followed by extract_lines()."""
+  diff_process = compute_diff(commit, files)
+  changed_lines = extract_lines(diff_process.stdout)
+  diff_process.stdout.close()
+  diff_process.wait()
+  if diff_process.returncode != 0:
+    # Assume error was already printed to stderr.
+    sys.exit(2)
+  return changed_lines
+
+
+def compute_diff(commit, files):
+  """Return a subprocess object producing the diff from `commit`.
+
+  The return value's `stdin` file object will produce a patch with the
+  differences between the working directory and `commit`, filtered on `files`
+  (if non-empty).  Zero context lines are used in the patch."""
+  cmd = ['git', 'diff-index', '-p', '-U0', commit, '--']
+  cmd.extend(files)
+  p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+  p.stdin.close()
+  return p
+
+
+def extract_lines(patch_file):
+  """Extract the changed lines in `patch_file`.
+
+  The return value is a dictionary mapping filename to a list of (start_line,
+  line_count) pairs.
+
+  The input must have been produced with ``-U0``, meaning unidiff format with
+  zero lines of context.  The return value is a dict mapping filename to a
+  list of line `Range`s."""
+  matches = {}
+  for line in patch_file:
+    match = re.search(r'^\+\+\+\ [^/]+/(.*)', line)
+    if match:
+      filename = match.group(1).rstrip('\r\n')
+    match = re.search(r'^@@ -[0-9,]+ \+(\d+)(,(\d+))?', line)
+    if match:
+      start_line = int(match.group(1))
+      line_count = 1
+      if match.group(3):
+        line_count = int(match.group(3))
+      if line_count > 0:
+        matches.setdefault(filename, []).append(Range(start_line, line_count))
+  return matches
+
+
+def filter_by_extension(dictionary, allowed_extensions):
+  """Delete every key in `dictionary` that doesn't have an allowed extension.
+
+  `allowed_extensions` must be a collection of lowercase file extensions,
+  excluding the period."""
+  allowed_extensions = frozenset(allowed_extensions)
+  for filename in dictionary.keys():
+    base_ext = filename.rsplit('.', 1)
+    if len(base_ext) == 1 or base_ext[1].lower() not in allowed_extensions:
+      del dictionary[filename]
+
+
+def cd_to_toplevel():
+  """Change to the top level of the git repository."""
+  toplevel = run('git', 'rev-parse', '--show-toplevel')
+  os.chdir(toplevel)
+
+
+def create_tree_from_workdir(filenames):
+  """Create a new git tree with the given files from the working directory.
+
+  Returns the object ID (SHA-1) of the created tree."""
+  return create_tree(filenames, '--stdin')
+
+
+def run_clang_format_and_save_to_tree(changed_lines, binary='clang-format',
+                                      style=None):
+  """Run clang-format on each file and save the result to a git tree.
+
+  Returns the object ID (SHA-1) of the created tree."""
+  def index_info_generator():
+    for filename, line_ranges in changed_lines.iteritems():
+      mode = oct(os.stat(filename).st_mode)
+      blob_id = clang_format_to_blob(filename, line_ranges, binary=binary,
+                                     style=style)
+      yield '%s %s\t%s' % (mode, blob_id, filename)
+  return create_tree(index_info_generator(), '--index-info')
+
+
+def create_tree(input_lines, mode):
+  """Create a tree object from the given input.
+
+  If mode is '--stdin', it must be a list of filenames.  If mode is
+  '--index-info' is must be a list of values suitable for "git update-index
+  --index-info", such as "<mode> <SP> <sha1> <TAB> <filename>".  Any other mode
+  is invalid."""
+  assert mode in ('--stdin', '--index-info')
+  cmd = ['git', 'update-index', '--add', '-z', mode]
+  with temporary_index_file():
+    p = subprocess.Popen(cmd, stdin=subprocess.PIPE)
+    for line in input_lines:
+      p.stdin.write('%s\0' % line)
+    p.stdin.close()
+    if p.wait() != 0:
+      die('`%s` failed' % ' '.join(cmd))
+    tree_id = run('git', 'write-tree')
+    return tree_id
+
+
+def clang_format_to_blob(filename, line_ranges, binary='clang-format',
+                         style=None):
+  """Run clang-format on the given file and save the result to a git blob.
+
+  Returns the object ID (SHA-1) of the created blob."""
+  clang_format_cmd = [binary, filename]
+  if style:
+    clang_format_cmd.extend(['-style='+style])
+  clang_format_cmd.extend([
+      '-lines=%s:%s' % (start_line, start_line+line_count-1)
+      for start_line, line_count in line_ranges])
+  try:
+    clang_format = subprocess.Popen(clang_format_cmd, stdin=subprocess.PIPE,
+                                    stdout=subprocess.PIPE)
+  except OSError as e:
+    if e.errno == errno.ENOENT:
+      die('cannot find executable "%s"' % binary)
+    else:
+      raise
+  clang_format.stdin.close()
+  hash_object_cmd = ['git', 'hash-object', '-w', '--path='+filename, '--stdin']
+  hash_object = subprocess.Popen(hash_object_cmd, stdin=clang_format.stdout,
+                                 stdout=subprocess.PIPE)
+  clang_format.stdout.close()
+  stdout = hash_object.communicate()[0]
+  if hash_object.returncode != 0:
+    die('`%s` failed' % ' '.join(hash_object_cmd))
+  if clang_format.wait() != 0:
+    die('`%s` failed' % ' '.join(clang_format_cmd))
+  return stdout.rstrip('\r\n')
+
+
+@contextlib.contextmanager
+def temporary_index_file(tree=None):
+  """Context manager for setting GIT_INDEX_FILE to a temporary file and deleting
+  the file afterward."""
+  index_path = create_temporary_index(tree)
+  old_index_path = os.environ.get('GIT_INDEX_FILE')
+  os.environ['GIT_INDEX_FILE'] = index_path
+  try:
+    yield
+  finally:
+    if old_index_path is None:
+      del os.environ['GIT_INDEX_FILE']
+    else:
+      os.environ['GIT_INDEX_FILE'] = old_index_path
+    os.remove(index_path)
+
+
+def create_temporary_index(tree=None):
+  """Create a temporary index file and return the created file's path.
+
+  If `tree` is not None, use that as the tree to read in.  Otherwise, an
+  empty index is created."""
+  gitdir = run('git', 'rev-parse', '--git-dir')
+  path = os.path.join(gitdir, temp_index_basename)
+  if tree is None:
+    tree = '--empty'
+  run('git', 'read-tree', '--index-output='+path, tree)
+  return path
+
+
+def print_diff(old_tree, new_tree):
+  """Print the diff between the two trees to stdout."""
+  # We use the porcelain 'diff' and not plumbing 'diff-tree' because the output
+  # is expected to be viewed by the user, and only the former does nice things
+  # like color and pagination.
+  subprocess.check_call(['git', 'diff', old_tree, new_tree, '--'])
+
+
+def apply_changes(old_tree, new_tree, force=False, patch_mode=False):
+  """Apply the changes in `new_tree` to the working directory.
+
+  Bails if there are local changes in those files and not `force`.  If
+  `patch_mode`, runs `git checkout --patch` to select hunks interactively."""
+  changed_files = run('git', 'diff-tree', '-r', '-z', '--name-only', old_tree,
+                      new_tree).rstrip('\0').split('\0')
+  if not force:
+    unstaged_files = run('git', 'diff-files', '--name-status', *changed_files)
+    if unstaged_files:
+      print >>sys.stderr, ('The following files would be modified but '
+                           'have unstaged changes:')
+      print >>sys.stderr, unstaged_files
+      print >>sys.stderr, 'Please commit, stage, or stash them first.'
+      sys.exit(2)
+  if patch_mode:
+    # In patch mode, we could just as well create an index from the new tree
+    # and checkout from that, but then the user will be presented with a
+    # message saying "Discard ... from worktree".  Instead, we use the old
+    # tree as the index and checkout from new_tree, which gives the slightly
+    # better message, "Apply ... to index and worktree".  This is not quite
+    # right, since it won't be applied to the user's index, but oh well.
+    with temporary_index_file(old_tree):
+      subprocess.check_call(['git', 'checkout', '--patch', new_tree])
+    index_tree = old_tree
+  else:
+    with temporary_index_file(new_tree):
+      run('git', 'checkout-index', '-a', '-f')
+  return changed_files
+
+
+def run(*args, **kwargs):
+  stdin = kwargs.pop('stdin', '')
+  verbose = kwargs.pop('verbose', True)
+  strip = kwargs.pop('strip', True)
+  for name in kwargs:
+    raise TypeError("run() got an unexpected keyword argument '%s'" % name)
+  p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                       stdin=subprocess.PIPE)
+  stdout, stderr = p.communicate(input=stdin)
+  if p.returncode == 0:
+    if stderr:
+      if verbose:
+        print >>sys.stderr, '`%s` printed to stderr:' % ' '.join(args)
+      print >>sys.stderr, stderr.rstrip()
+    if strip:
+      stdout = stdout.rstrip('\r\n')
+    return stdout
+  if verbose:
+    print >>sys.stderr, '`%s` returned %s' % (' '.join(args), p.returncode)
+  if stderr:
+    print >>sys.stderr, stderr.rstrip()
+  sys.exit(2)
+
+
+def die(message):
+  print >>sys.stderr, 'error:', message
+  sys.exit(2)
+
+
+if __name__ == '__main__':
+  main()
\ No newline at end of file
diff --git a/pre-commit.readme b/pre-commit.readme
new file mode 100644
index 0000000000..aae63f23f7
--- /dev/null
+++ b/pre-commit.readme
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# git pre-commit hook that run git-clang-format when committing.
+# To use it install clang-format and python 2.7 then copy this
+# file to .git/hooks/ and remove the extension
+
+git clang-format --style=file --diff > style.patch
+git apply --index style.patch
+rm style.patch
+exit 0