diff --git a/CMakeLists.txt b/CMakeLists.txt
index a0c61dac..12b65148 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -91,19 +91,24 @@ enable_testing()
 
 include_directories(.)
 
-set(TEST_MAIN_SRC test/test-main.cc test/gtest-extra.cc test/gtest-extra.h)
+set(TEST_MAIN_SRC
+  test/test-main.cc test/gtest-extra.cc test/gtest-extra.h test/util.cc)
 add_library(test-main ${TEST_MAIN_SRC})
 target_link_libraries(test-main gtest format)
 
 cxx_test(gtest-extra-test test-main)
 cxx_test(format-test test-main)
-if (CMAKE_COMPILER_IS_GNUCXX)
-  set_target_properties(format-test PROPERTIES COMPILE_FLAGS
-    "-Wall -Wextra -pedantic -Wno-long-long -Wno-variadic-macros")
-endif ()
-if (CPP11_FLAG)
-  set_target_properties(format-test PROPERTIES COMPILE_FLAGS ${CPP11_FLAG})
-endif ()
+cxx_test(printf-test test-main)
+foreach (target format-test printf-test)
+  if (CMAKE_COMPILER_IS_GNUCXX)
+    set_target_properties(${target} PROPERTIES COMPILE_FLAGS
+      "-Wall -Wextra -pedantic -Wno-long-long -Wno-variadic-macros")
+  endif ()
+  if (CPP11_FLAG)
+    set_target_properties(${target} PROPERTIES COMPILE_FLAGS ${CPP11_FLAG})
+  endif ()
+endforeach ()
+cxx_test(util-test test-main)
 
 if (HAVE_OPEN)
   add_executable(posix-test test/posix-test.cc ${TEST_MAIN_SRC})
diff --git a/format.cc b/format.cc
index 1776456f..0606631d 100644
--- a/format.cc
+++ b/format.cc
@@ -289,6 +289,44 @@ void fmt::internal::FormatWinErrorMessage(
 }
 #endif
 
+template <typename Char>
+void fmt::internal::FormatErrorReporter<Char>::operator()(
+        const Char *s, fmt::StringRef message) const {
+  for (int n = num_open_braces; *s; ++s) {
+    if (*s == '{') {
+      ++n;
+    } else if (*s == '}') {
+      if (--n == 0)
+        throw fmt::FormatError(message);
+    }
+  }
+  throw fmt::FormatError("unmatched '{' in format");
+}
+
+// Parses an unsigned integer advancing s to the end of the parsed input.
+// This function assumes that the first character of s is a digit.
+template <typename Char>
+int fmt::internal::ParseNonnegativeInt(
+    const Char *&s, const char *&error) FMT_NOEXCEPT(true) {
+  assert('0' <= *s && *s <= '9');
+  unsigned value = 0;
+  do {
+    unsigned new_value = value * 10 + (*s++ - '0');
+    // Check if value wrapped around.
+    value = new_value >= value ? new_value : UINT_MAX;
+  } while ('0' <= *s && *s <= '9');
+  if (value > INT_MAX) {
+    if (!error)
+      error = "number is too big in format";
+    return 0;
+  }
+  return value;
+}
+
+template <typename Char>
+const typename fmt::BasicWriter<Char>::ArgInfo
+  fmt::BasicWriter<Char>::DUMMY_ARG = {fmt::BasicWriter<Char>::INT, 0};
+
 // Fills the padding around the content and returns the pointer to the
 // content area.
 template <typename Char>
@@ -494,60 +532,31 @@ void fmt::BasicWriter<Char>::FormatDouble(
   }
 }
 
-// Throws Exception(message) if format contains '}', otherwise throws
-// FormatError reporting unmatched '{'. The idea is that unmatched '{'
-// should override other errors.
-template <typename Char>
-void fmt::BasicWriter<Char>::FormatParser::ReportError(
-    const Char *s, StringRef message) const {
-  for (int num_open_braces = num_open_braces_; *s; ++s) {
-    if (*s == '{') {
-      ++num_open_braces;
-    } else if (*s == '}') {
-      if (--num_open_braces == 0)
-        throw fmt::FormatError(message);
-    }
-  }
-  throw fmt::FormatError("unmatched '{' in format");
-}
-
-// Parses an unsigned integer advancing s to the end of the parsed input.
-// This function assumes that the first character of s is a digit.
-template <typename Char>
-unsigned fmt::BasicWriter<Char>::FormatParser::ParseUInt(const Char *&s) const {
-  assert('0' <= *s && *s <= '9');
-  unsigned value = 0;
-  do {
-    unsigned new_value = value * 10 + (*s++ - '0');
-    if (new_value < value)  // Check if value wrapped around.
-      ReportError(s, "number is too big in format");
-    value = new_value;
-  } while ('0' <= *s && *s <= '9');
-  return value;
-}
-
 template <typename Char>
 inline const typename fmt::BasicWriter<Char>::ArgInfo
     &fmt::BasicWriter<Char>::FormatParser::ParseArgIndex(const Char *&s) {
   unsigned arg_index = 0;
   if (*s < '0' || *s > '9') {
     if (*s != '}' && *s != ':')
-      ReportError(s, "invalid argument index in format string");
+      report_error_(s, "invalid argument index in format string");
     if (next_arg_index_ < 0) {
-      ReportError(s,
+      report_error_(s,
           "cannot switch from manual to automatic argument indexing");
     }
     arg_index = next_arg_index_++;
   } else {
     if (next_arg_index_ > 0) {
-      ReportError(s,
+      report_error_(s,
           "cannot switch from automatic to manual argument indexing");
     }
     next_arg_index_ = -1;
-    arg_index = ParseUInt(s);
+    const char *error = 0;
+    arg_index = internal::ParseNonnegativeInt(s, error);
+    if (error)
+      report_error_(s, error); // TODO
   }
   if (arg_index >= num_args_)
-    ReportError(s, "argument index is out of range in format");
+    report_error_(s, "argument index is out of range in format");
   return args_[arg_index];
 }
 
@@ -556,18 +565,18 @@ void fmt::BasicWriter<Char>::FormatParser::CheckSign(
     const Char *&s, const ArgInfo &arg) {
   char sign = static_cast<char>(*s);
   if (arg.type > LAST_NUMERIC_TYPE) {
-    ReportError(s,
+    report_error_(s,
         fmt::Format("format specifier '{}' requires numeric argument") << sign);
   }
   if (arg.type == UINT || arg.type == ULONG || arg.type == ULONG_LONG) {
-    ReportError(s,
+    report_error_(s,
         fmt::Format("format specifier '{}' requires signed argument") << sign);
   }
   ++s;
 }
 
 template <typename Char>
-void fmt::BasicWriter<Char>::FormatParser::Format(
+void fmt::BasicWriter<Char>::PrintfParser::Format(
     BasicWriter<Char> &writer, BasicStringRef<Char> format,
     std::size_t num_args, const ArgInfo *args) {
   const Char *start = format.c_str();
@@ -577,24 +586,86 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
   const Char *s = start;
   while (*s) {
     Char c = *s++;
-    if (c != '{' && c != '}') continue;
+    if (c != '%') continue;
     if (*s == c) {
       writer.buffer_.append(start, s);
       start = ++s;
       continue;
     }
-    if (c == '}')
-      throw FormatError("unmatched '}' in format");
-    num_open_braces_= 1;
     writer.buffer_.append(start, s - 1);
 
-    const ArgInfo &arg = ParseArgIndex(s);
-
     FormatSpec spec;
-    int precision = -1;
-    if (*s == ':') {
-      ++s;
+    spec.align_ = ALIGN_RIGHT;
 
+    // Reporting errors is delayed till the format specification is
+    // completely parsed. This is done to avoid potentially confusing
+    // error messages for incomplete format strings. For example, in
+    //   sprintf("%2$", 42);
+    // the format specification is incomplete. In naive approach we
+    // would parse 2 as an argument index and report an error that the
+    // index is out of range which would be rather confusing if the
+    // use meant "%2d$" rather than "%2$d". If we delay an error, the
+    // user will get an error that the format string is invalid which
+    // is OK for both cases.
+    const char *error = 0;
+
+    unsigned arg_index = 0;
+    bool have_width = false, have_arg_index = false;
+    if (*s >= '0' && *s <= '9') {
+      unsigned value = internal::ParseNonnegativeInt(s, error);
+      if (*s != '$') {
+        // TODO: handle '0'
+        have_width = true;
+        spec.width_ = value;
+      } else {
+        ++s;
+        if (next_arg_index_ <= 0) {
+          have_arg_index = true;
+          next_arg_index_ = -1;
+          arg_index = value - 1;
+        } else if (!error) {
+          error = "cannot switch from automatic to manual argument indexing";
+        }
+      }
+    }
+    if (!have_arg_index) {
+      if (next_arg_index_ >= 0) {
+        arg_index = next_arg_index_++;
+      } else {
+        // We don't check if error has already been set because argument
+        // index is semantically the first part of the format string, so
+        // indexing errors are reported first even though parsing width
+        // above can cause another error.
+        error = "cannot switch from manual to automatic argument indexing";
+      }
+    }
+
+    const ArgInfo *arg = 0;
+    if (arg_index < num_args) {
+      arg = &args_[arg_index];
+    } else {
+      arg = &DUMMY_ARG;
+      if (!error)
+        error = "argument index is out of range in format";
+    }
+
+    int precision = -1;
+    switch (have_width) {
+    case false:
+      // TODO: parse optional flags
+      switch (*s) {
+        case '-':
+          ++s;
+          spec.align_ = ALIGN_LEFT;
+          break;
+        case '+':
+        case ' ':
+        case '#':
+          //++s;
+          break;
+      }
+
+      /*
       // Parse fill and alignment.
       if (Char c = *s) {
         const Char *p = s + 1;
@@ -649,22 +720,272 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
           ReportError(s, "format specifier '#' requires numeric argument");
         spec.flags_ |= HASH_FLAG;
         ++s;
+      }*/
+
+      // Parse width and zero flag.
+      if (*s < '0' || *s > '9')
+        break;
+      if (*s == '0') {
+        spec.align_ = ALIGN_NUMERIC;
+        spec.fill_ = '0';
+      }
+      // Zero may be parsed again as a part of the width, but it is simpler
+      // and more efficient than checking if the next char is a digit.
+      spec.width_ = internal::ParseNonnegativeInt(s, error);
+      // Fall through.
+    default:
+      if (spec.fill_ == '0' && arg->type > LAST_NUMERIC_TYPE)
+        throw FormatError("format specifier '0' requires numeric argument");
+      break;
+    }
+
+    // Parse precision.
+    /*if (*s == '.') {
+      ++s;
+      precision = 0;
+      if ('0' <= *s && *s <= '9') {
+        unsigned value = ParseNonnegativeInt(s);
+        if (value > INT_MAX)
+          ReportError(s, "number is too big in format");
+        precision = value;
+      } else if (*s == '{') {
+        ++s;
+        ++num_open_braces_;
+        const ArgInfo &precision_arg = ParseArgIndex(s);
+        ULongLong value = 0;
+        switch (precision_arg.type) {
+        case INT:
+          if (precision_arg.int_value < 0)
+            ReportError(s, "negative precision in format");
+          value = precision_arg.int_value;
+          break;
+        case UINT:
+          value = precision_arg.uint_value;
+          break;
+        case LONG:
+          if (precision_arg.long_value < 0)
+            ReportError(s, "negative precision in format");
+          value = precision_arg.long_value;
+          break;
+        case ULONG:
+          value = precision_arg.ulong_value;
+          break;
+        case LONG_LONG:
+          if (precision_arg.long_long_value < 0)
+            ReportError(s, "negative precision in format");
+          value = precision_arg.long_long_value;
+          break;
+        case ULONG_LONG:
+          value = precision_arg.ulong_long_value;
+          break;
+        default:
+          ReportError(s, "precision is not integer");
+        }
+        if (value > INT_MAX)
+          ReportError(s, "number is too big in format");
+        precision = static_cast<int>(value);
+        if (*s++ != '}')
+          throw FormatError("unmatched '{' in format");
+        --num_open_braces_;
+      } else {
+        ReportError(s, "missing precision in format");
+      }
+      if (arg.type != DOUBLE && arg.type != LONG_DOUBLE) {
+        ReportError(s,
+            "precision specifier requires floating-point argument");
+      }
+    }*/
+
+    // Parse type.
+    if (!*s)
+      throw FormatError("invalid format string");
+    if (error)
+      throw FormatError(error);
+    spec.type_ = static_cast<char>(*s++);
+
+    start = s;
+
+    // Format argument.
+    switch (arg->type) {
+    case INT:
+      writer.FormatInt(arg->int_value, spec);
+      break;
+    case UINT:
+      writer.FormatInt(arg->uint_value, spec);
+      break;
+    case LONG:
+      writer.FormatInt(arg->long_value, spec);
+      break;
+    case ULONG:
+      writer.FormatInt(arg->ulong_value, spec);
+      break;
+    case LONG_LONG:
+      writer.FormatInt(arg->long_long_value, spec);
+      break;
+    case ULONG_LONG:
+      writer.FormatInt(arg->ulong_long_value, spec);
+      break;
+    case DOUBLE:
+      writer.FormatDouble(arg->double_value, spec, precision);
+      break;
+    case LONG_DOUBLE:
+      writer.FormatDouble(arg->long_double_value, spec, precision);
+      break;
+    case CHAR: {
+      if (spec.type_ && spec.type_ != 'c')
+        internal::ReportUnknownType(spec.type_, "char");
+      typedef typename BasicWriter<Char>::CharPtr CharPtr;
+      CharPtr out = CharPtr();
+      if (spec.width_ > 1) {
+        Char fill = static_cast<Char>(spec.fill());
+        out = writer.GrowBuffer(spec.width_);
+        if (spec.align_ == ALIGN_RIGHT) {
+          std::fill_n(out, spec.width_ - 1, fill);
+          out += spec.width_ - 1;
+        } else if (spec.align_ == ALIGN_CENTER) {
+          out = writer.FillPadding(out, spec.width_, 1, fill);
+        } else {
+          std::fill_n(out + 1, spec.width_ - 1, fill);
+        }
+      } else {
+        out = writer.GrowBuffer(1);
+      }
+      *out = static_cast<Char>(arg->int_value);
+      break;
+    }
+    case STRING: {
+      if (spec.type_ && spec.type_ != 's')
+        internal::ReportUnknownType(spec.type_, "string");
+      const Char *str = arg->string.value;
+      std::size_t size = arg->string.size;
+      if (size == 0) {
+        if (!str)
+          throw FormatError("string pointer is null");
+        if (*str)
+          size = std::char_traits<Char>::length(str);
+      }
+      writer.FormatString(str, size, spec);
+      break;
+    }
+    case POINTER:
+      if (spec.type_ && spec.type_ != 'p')
+        internal::ReportUnknownType(spec.type_, "pointer");
+      spec.flags_= HASH_FLAG;
+      spec.type_ = 'x';
+      writer.FormatInt(reinterpret_cast<uintptr_t>(arg->pointer_value), spec);
+      break;
+    case CUSTOM:
+      if (spec.type_)
+        internal::ReportUnknownType(spec.type_, "object");
+      arg->custom.format(writer, arg->custom.value, spec);
+      break;
+    default:
+      assert(false);
+      break;
+    }
+  }
+  writer.buffer_.append(start, s);
+}
+
+template <typename Char>
+void fmt::BasicWriter<Char>::FormatParser::Format(
+    BasicWriter<Char> &writer, BasicStringRef<Char> format,
+    std::size_t num_args, const ArgInfo *args) {
+  const char *error = 0;
+  const Char *start = format.c_str();
+  num_args_ = num_args;
+  args_ = args;
+  next_arg_index_ = 0;
+  const Char *s = start;
+  while (*s) {
+    Char c = *s++;
+    if (c != '{' && c != '}') continue;
+    if (*s == c) {
+      writer.buffer_.append(start, s);
+      start = ++s;
+      continue;
+    }
+    if (c == '}')
+      throw FormatError("unmatched '}' in format");
+    report_error_.num_open_braces = 1;
+    writer.buffer_.append(start, s - 1);
+
+    const ArgInfo &arg = ParseArgIndex(s);
+
+    FormatSpec spec;
+    int precision = -1;
+    if (*s == ':') {
+      ++s;
+
+      // Parse fill and alignment.
+      if (Char c = *s) {
+        const Char *p = s + 1;
+        spec.align_ = ALIGN_DEFAULT;
+        do {
+          switch (*p) {
+          case '<':
+            spec.align_ = ALIGN_LEFT;
+            break;
+          case '>':
+            spec.align_ = ALIGN_RIGHT;
+            break;
+          case '=':
+            spec.align_ = ALIGN_NUMERIC;
+            break;
+          case '^':
+            spec.align_ = ALIGN_CENTER;
+            break;
+          }
+          if (spec.align_ != ALIGN_DEFAULT) {
+            if (p != s) {
+              if (c == '}') break;
+              if (c == '{')
+                report_error_(s, "invalid fill character '{'");
+              s += 2;
+              spec.fill_ = c;
+            } else ++s;
+            if (spec.align_ == ALIGN_NUMERIC && arg.type > LAST_NUMERIC_TYPE)
+              report_error_(s, "format specifier '=' requires numeric argument");
+            break;
+          }
+        } while (--p >= s);
+      }
+
+      // Parse sign.
+      switch (*s) {
+      case '+':
+        CheckSign(s, arg);
+        spec.flags_ |= SIGN_FLAG | PLUS_FLAG;
+        break;
+      case '-':
+        CheckSign(s, arg);
+        break;
+      case ' ':
+        CheckSign(s, arg);
+        spec.flags_ |= SIGN_FLAG;
+        break;
+      }
+
+      if (*s == '#') {
+        if (arg.type > LAST_NUMERIC_TYPE)
+          report_error_(s, "format specifier '#' requires numeric argument");
+        spec.flags_ |= HASH_FLAG;
+        ++s;
       }
 
       // Parse width and zero flag.
       if ('0' <= *s && *s <= '9') {
         if (*s == '0') {
           if (arg.type > LAST_NUMERIC_TYPE)
-            ReportError(s, "format specifier '0' requires numeric argument");
+            report_error_(s, "format specifier '0' requires numeric argument");
           spec.align_ = ALIGN_NUMERIC;
           spec.fill_ = '0';
         }
         // Zero may be parsed again as a part of the width, but it is simpler
         // and more efficient than checking if the next char is a digit.
-        unsigned value = ParseUInt(s);
-        if (value > INT_MAX)
-          ReportError(s, "number is too big in format");
-        spec.width_ = value;
+        spec.width_ = internal::ParseNonnegativeInt(s, error);
+        if (error)
+          report_error_(s, error);
       }
 
       // Parse precision.
@@ -672,19 +993,18 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
         ++s;
         precision = 0;
         if ('0' <= *s && *s <= '9') {
-          unsigned value = ParseUInt(s);
-          if (value > INT_MAX)
-            ReportError(s, "number is too big in format");
-          precision = value;
+          precision = internal::ParseNonnegativeInt(s, error);
+          if (error)
+            report_error_(s, error);
         } else if (*s == '{') {
           ++s;
-          ++num_open_braces_;
+          ++report_error_.num_open_braces;
           const ArgInfo &precision_arg = ParseArgIndex(s);
           ULongLong value = 0;
           switch (precision_arg.type) {
           case INT:
             if (precision_arg.int_value < 0)
-              ReportError(s, "negative precision in format");
+              report_error_(s, "negative precision in format");
             value = precision_arg.int_value;
             break;
           case UINT:
@@ -692,7 +1012,7 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
             break;
           case LONG:
             if (precision_arg.long_value < 0)
-              ReportError(s, "negative precision in format");
+              report_error_(s, "negative precision in format");
             value = precision_arg.long_value;
             break;
           case ULONG:
@@ -700,26 +1020,26 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
             break;
           case LONG_LONG:
             if (precision_arg.long_long_value < 0)
-              ReportError(s, "negative precision in format");
+              report_error_(s, "negative precision in format");
             value = precision_arg.long_long_value;
             break;
           case ULONG_LONG:
             value = precision_arg.ulong_long_value;
             break;
           default:
-            ReportError(s, "precision is not integer");
+            report_error_(s, "precision is not integer");
           }
           if (value > INT_MAX)
-            ReportError(s, "number is too big in format");
+            report_error_(s, "number is too big in format");
           precision = static_cast<int>(value);
           if (*s++ != '}')
             throw FormatError("unmatched '{' in format");
-          --num_open_braces_;
+          --report_error_.num_open_braces;
         } else {
-          ReportError(s, "missing precision in format");
+          report_error_(s, "missing precision in format");
         }
         if (arg.type != DOUBLE && arg.type != LONG_DOUBLE) {
-          ReportError(s,
+          report_error_(s,
               "precision specifier requires floating-point argument");
         }
       }
@@ -852,12 +1172,6 @@ void fmt::ANSITerminalSink::operator()(
 
 // Explicit instantiations for char.
 
-template void fmt::BasicWriter<char>::FormatDouble<double>(
-    double value, const FormatSpec &spec, int precision);
-
-template void fmt::BasicWriter<char>::FormatDouble<long double>(
-    long double value, const FormatSpec &spec, int precision);
-
 template fmt::BasicWriter<char>::CharPtr
   fmt::BasicWriter<char>::FillPadding(CharPtr buffer,
     unsigned total_size, std::size_t content_size, wchar_t fill);
@@ -866,53 +1180,31 @@ template fmt::BasicWriter<char>::CharPtr
   fmt::BasicWriter<char>::PrepareFilledBuffer(
     unsigned size, const AlignSpec &spec, char sign);
 
-template void fmt::BasicWriter<char>::FormatParser::ReportError(
-    const char *s, StringRef message) const;
-
-template unsigned fmt::BasicWriter<char>::FormatParser::ParseUInt(
-    const char *&s) const;
-
-template const fmt::BasicWriter<char>::ArgInfo
-    &fmt::BasicWriter<char>::FormatParser::ParseArgIndex(const char *&s);
-
-template void fmt::BasicWriter<char>::FormatParser::CheckSign(
-    const char *&s, const ArgInfo &arg);
-
 template void fmt::BasicWriter<char>::FormatParser::Format(
   BasicWriter<char> &writer, BasicStringRef<char> format,
   std::size_t num_args, const ArgInfo *args);
 
+template void fmt::BasicWriter<char>::PrintfParser::Format(
+  BasicWriter<char> &writer, BasicStringRef<char> format,
+  std::size_t num_args, const ArgInfo *args);
+
 // Explicit instantiations for wchar_t.
 
-template void fmt::BasicWriter<wchar_t>::FormatDouble<double>(
-    double value, const FormatSpec &spec, int precision);
-
-template void fmt::BasicWriter<wchar_t>::FormatDouble<long double>(
-    long double value, const FormatSpec &spec, int precision);
-
 template fmt::BasicWriter<wchar_t>::CharPtr
   fmt::BasicWriter<wchar_t>::FillPadding(CharPtr buffer,
-      unsigned total_size, std::size_t content_size, wchar_t fill);
+    unsigned total_size, std::size_t content_size, wchar_t fill);
 
 template fmt::BasicWriter<wchar_t>::CharPtr
   fmt::BasicWriter<wchar_t>::PrepareFilledBuffer(
     unsigned size, const AlignSpec &spec, char sign);
 
-template void fmt::BasicWriter<wchar_t>::FormatParser::ReportError(
-    const wchar_t *s, StringRef message) const;
-
-template unsigned fmt::BasicWriter<wchar_t>::FormatParser::ParseUInt(
-    const wchar_t *&s) const;
-
-template const fmt::BasicWriter<wchar_t>::ArgInfo
-    &fmt::BasicWriter<wchar_t>::FormatParser::ParseArgIndex(const wchar_t *&s);
-
-template void fmt::BasicWriter<wchar_t>::FormatParser::CheckSign(
-    const wchar_t *&s, const ArgInfo &arg);
-
 template void fmt::BasicWriter<wchar_t>::FormatParser::Format(
-        BasicWriter<wchar_t> &writer, BasicStringRef<wchar_t> format,
-        std::size_t num_args, const ArgInfo *args);
+    BasicWriter<wchar_t> &writer, BasicStringRef<wchar_t> format,
+    std::size_t num_args, const ArgInfo *args);
+
+template void fmt::BasicWriter<wchar_t>::PrintfParser::Format(
+    BasicWriter<wchar_t> &writer, BasicStringRef<wchar_t> format,
+    std::size_t num_args, const ArgInfo *args);
 
 #if _MSC_VER
 # pragma warning(pop)
diff --git a/format.h b/format.h
index b1d8d609..3f8a46b9 100644
--- a/format.h
+++ b/format.h
@@ -186,6 +186,15 @@ class BasicStringRef {
 typedef BasicStringRef<char> StringRef;
 typedef BasicStringRef<wchar_t> WStringRef;
 
+/**
+  A formatting error such as invalid format string.
+*/
+class FormatError : public std::runtime_error {
+public:
+  explicit FormatError(const std::string &message)
+  : std::runtime_error(message) {}
+};
+
 namespace internal {
 
 // The number of characters to store in the Array object, representing the
@@ -509,17 +518,29 @@ void FormatWinErrorMessage(
     fmt::Writer &out, int error_code, fmt::StringRef message);
 #endif
 
-}  // namespace internal
-
-/**
-  A formatting error such as invalid format string.
- */
-class FormatError : public std::runtime_error {
- public:
-  explicit FormatError(const std::string &message)
-  : std::runtime_error(message) {}
+struct SimpleErrorReporter {
+  void operator()(const void *, fmt::StringRef message) const {
+    throw fmt::FormatError(message);
+  }
 };
 
+// Throws Exception(message) if format contains '}', otherwise throws
+// FormatError reporting unmatched '{'. The idea is that unmatched '{'
+// should override other errors.
+template <typename Char>
+struct FormatErrorReporter {
+  int num_open_braces;
+  void operator()(const Char *s, fmt::StringRef message) const;
+};
+
+// Parses a nonnegative integer advancing s to the end of the parsed input.
+// This function assumes that the first character of s is a digit.
+template <typename Char>
+int ParseNonnegativeInt(
+  const Char *&s, const char *&error) FMT_NOEXCEPT(true);
+
+}  // namespace internal
+
 /**
   An error returned by an operating system or a language runtime,
   for example a file opening error.
@@ -881,6 +902,8 @@ class BasicWriter {
     };
   };
 
+  static const ArgInfo DUMMY_ARG;
+
   // An argument action that does nothing.
   struct NullArgAction {
     void operator()() const {}
@@ -978,12 +1001,8 @@ class BasicWriter {
    private:
     std::size_t num_args_;
     const ArgInfo *args_;
-    int num_open_braces_;
     int next_arg_index_;
-
-    void ReportError(const Char *s, StringRef message) const;
-
-    unsigned ParseUInt(const Char *&s) const;
+    fmt::internal::FormatErrorReporter<Char> report_error_;
 
     // Parses argument index and returns an argument with this index.
     const ArgInfo &ParseArgIndex(const Char *&s);
@@ -995,6 +1014,18 @@ class BasicWriter {
       BasicStringRef<Char> format, std::size_t num_args, const ArgInfo *args);
   };
 
+  // Printf format string parser.
+  class PrintfParser {
+   private:
+    std::size_t num_args_;
+    const ArgInfo *args_;
+    int next_arg_index_;
+
+  public:
+    void Format(BasicWriter<Char> &writer,
+      BasicStringRef<Char> format, std::size_t num_args, const ArgInfo *args);
+  };
+
  public:
   /**
     Constructs a ``BasicWriter`` object.
@@ -1052,6 +1083,11 @@ class BasicWriter {
     FormatParser().Format(*this, format, num_args, args);
   }
 
+  inline void vprintf(BasicStringRef<Char> format,
+      std::size_t num_args, const ArgInfo *args) {
+    PrintfParser().Format(*this, format, num_args, args);
+  }
+
   /**
     \rst
     Formats a string sending the output to the writer. Arguments are
@@ -1112,6 +1148,12 @@ class BasicWriter {
     Arg arg_array[] = {args...};
     VFormat(format, sizeof...(Args), arg_array);
   }
+
+  template<typename... Args>
+  void printf(BasicStringRef<Char> format, const Args & ... args) {
+    Arg arg_array[] = {args...};
+    vprintf(format, sizeof...(Args), arg_array);
+  }
 #endif
 
   BasicWriter &operator<<(int value) {
@@ -1726,7 +1768,7 @@ inline Formatter<ANSITerminalSink> PrintColored(Color c, StringRef format) {
   Formats a string similarly to Python's `str.format
   <http://docs.python.org/3/library/stdtypes.html#str.format>`__ function
   and returns an :cpp:class:`fmt::BasicWriter` object containing the output.
-  
+
   This version of the Format function uses C++11 features such as
   variadic templates and rvalue references. For C++98 version, see
   the :cpp:func:`fmt::Format()` overload above.
@@ -1773,6 +1815,20 @@ void Print(std::FILE *f, StringRef format, const Args & ... args) {
   std::fwrite(w.data(), 1, w.size(), f);
 }
 
+template<typename... Args>
+inline Writer sprintf(StringRef format, const Args & ... args) {
+  Writer w;
+  w.printf(format, args...);
+  return std::move(w);
+}
+
+template<typename... Args>
+void printf(StringRef format, const Args & ... args) {
+  Writer w;
+  w.printf(format, args...);
+  std::fwrite(w.data(), 1, w.size(), stdout);
+}
+
 #endif  // FMT_USE_VARIADIC_TEMPLATES && FMT_USE_RVALUE_REFERENCES
 
 /**
diff --git a/test/format-test.cc b/test/format-test.cc
index a1570828..45cfe824 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -49,6 +49,7 @@ FILE *FOpen(const char *filename, const char *mode) {
 #endif
 
 #include "format.h"
+#include "util.h"
 #include "gtest-extra.h"
 
 #include <stdint.h>
@@ -110,19 +111,6 @@ struct WriteChecker {
 #define CHECK_WRITE_WCHAR(value) \
   EXPECT_PRED_FORMAT1(WriteChecker<wchar_t>(), value)
 
-// Increment a number in a string.
-void Increment(char *s) {
-  for (int i = static_cast<int>(std::strlen(s)) - 1; i >= 0; --i) {
-    if (s[i] != '9') {
-      ++s[i];
-      break;
-    }
-    s[i] = '0';
-  }
-}
-
-enum {BUFFER_SIZE = 256};
-
 #ifdef _MSC_VER
 # define vsnprintf vsprintf_s
 #endif
@@ -134,234 +122,13 @@ void SPrintf(char *buffer, const char *format, ...) {
   va_end(args);
 }
 
-std::string ReadFile(fmt::StringRef filename) {
+std::string ReadFile(StringRef filename) {
   std::ifstream out(filename.c_str());
   std::stringstream content;
   content << out.rdbuf();
   return content.str();
 }
-
-std::string GetSystemErrorMessage(int error_code) {
-#ifndef _WIN32
-  return strerror(error_code);
-#else
-  enum { BUFFER_SIZE = 200 };
-  char buffer[BUFFER_SIZE];
-  EXPECT_EQ(0, strerror_s(buffer, BUFFER_SIZE, error_code));
-  std::size_t max_len = BUFFER_SIZE - 1;
-  EXPECT_LT(std::strlen(buffer), max_len);
-  return buffer;
-#endif
 }
-}
-
-TEST(UtilTest, Increment) {
-  char s[10] = "123";
-  Increment(s);
-  EXPECT_STREQ("124", s);
-  s[2] = '8';
-  Increment(s);
-  EXPECT_STREQ("129", s);
-  Increment(s);
-  EXPECT_STREQ("130", s);
-  s[1] = s[2] = '9';
-  Increment(s);
-  EXPECT_STREQ("200", s);
-}
-
-// Tests fmt::internal::CountDigits for integer type Int.
-template <typename Int>
-void TestCountDigits(Int) {
-  for (Int i = 0; i < 10; ++i)
-    EXPECT_EQ(1u, fmt::internal::CountDigits(i));
-  for (Int i = 1, n = 1,
-       end = std::numeric_limits<Int>::max() / 10; n <= end; ++i) {
-    n *= 10;
-    EXPECT_EQ(i, fmt::internal::CountDigits(n - 1));
-    EXPECT_EQ(i + 1, fmt::internal::CountDigits(n));
-  }
-}
-
-TEST(UtilTest, CountDigits) {
-  TestCountDigits(uint32_t());
-  TestCountDigits(uint64_t());
-}
-
-#ifdef _WIN32
-TEST(UtilTest, UTF16ToUTF8) {
-  std::string s = "ёжик";
-  fmt::internal::UTF16ToUTF8 u(L"\x0451\x0436\x0438\x043A");
-  EXPECT_EQ(s, fmt::str(u));
-  EXPECT_EQ(s.size(), u.size());
-}
-
-TEST(UtilTest, UTF8ToUTF16) {
-  std::string s = "лошадка";
-  fmt::internal::UTF8ToUTF16 u(s.c_str());
-  EXPECT_EQ(L"\x043B\x043E\x0448\x0430\x0434\x043A\x0430", fmt::str(u));
-  EXPECT_EQ(7, u.size());
-}
-
-template <typename Converter>
-void CheckUTFConversionError(const char *message) {
-  fmt::Writer out;
-  fmt::internal::FormatWinErrorMessage(out, ERROR_INVALID_PARAMETER, message);
-  fmt::SystemError error("", 0);
-  try {
-    Converter(0);
-  } catch (const fmt::SystemError &e) {
-    error = e;
-  }
-  EXPECT_EQ(ERROR_INVALID_PARAMETER, error.error_code());
-  EXPECT_EQ(out.str(), error.what());
-}
-
-TEST(UtilTest, UTF16ToUTF8Error) {
-  CheckUTFConversionError<fmt::internal::UTF16ToUTF8>(
-      "cannot convert string from UTF-16 to UTF-8");
-}
-
-TEST(UtilTest, UTF8ToUTF16Error) {
-  CheckUTFConversionError<fmt::internal::UTF8ToUTF16>(
-      "cannot convert string from UTF-8 to UTF-16");
-}
-
-TEST(UtilTest, UTF16ToUTF8Convert) {
-  fmt::internal::UTF16ToUTF8 u;
-  EXPECT_EQ(ERROR_INVALID_PARAMETER, u.Convert(0));
-}
-#endif  // _WIN32
-
-TEST(UtilTest, StrError) {
-  using fmt::internal::StrError;
-  char *message = 0;
-  char buffer[BUFFER_SIZE];
-#ifndef NDEBUG
-  EXPECT_DEBUG_DEATH(StrError(EDOM, message = 0, 0), "Assertion");
-  EXPECT_DEBUG_DEATH(StrError(EDOM, message = buffer, 0), "Assertion");
-#endif
-  buffer[0] = 'x';
-#ifdef _GNU_SOURCE
-  // Use invalid error code to make sure that StrError returns an error
-  // message in the buffer rather than a pointer to a static string.
-  int error_code = -1;
-#else
-  int error_code = EDOM;
-#endif
-  int result = StrError(error_code, message = buffer, 1);
-  EXPECT_EQ(buffer, message);  // Message should point to buffer.
-  EXPECT_EQ(ERANGE, result);
-  EXPECT_STREQ("", message);
-  result = StrError(error_code, message = buffer, BUFFER_SIZE);
-  EXPECT_EQ(0, result);
-  std::size_t message_size = std::strlen(message);
-  EXPECT_GE(BUFFER_SIZE - 1u, message_size);
-  EXPECT_EQ(GetSystemErrorMessage(error_code), message);
-  result = StrError(error_code, message = buffer, message_size);
-  EXPECT_EQ(ERANGE, result);
-}
-
-TEST(UtilTest, SystemError) {
-  fmt::SystemError e(fmt::StringRef("test"), 42);
-  EXPECT_STREQ("test", e.what());
-  EXPECT_EQ(42, e.error_code());
-}
-
-typedef void (*FormatErrorMessage)(
-    fmt::Writer &out, int error_code, fmt::StringRef message);
-
-template <typename Sink>
-void CheckErrorSink(int error_code, FormatErrorMessage format) {
-  fmt::SystemError error("", 0);
-  Sink sink(error_code);
-  fmt::Writer w;
-  w << "test";
-  try {
-    sink(w);
-  } catch (const fmt::SystemError &e) {
-    error = e;
-  }
-  fmt::Writer message;
-  format(message, error_code, "test");
-  EXPECT_EQ(str(message), error.what());
-  EXPECT_EQ(error_code, error.error_code());
-}
-
-template <typename Sink>
-void CheckThrowError(int error_code, FormatErrorMessage format,
-    fmt::Formatter<Sink> (*throw_error)(int error_code, StringRef format)) {
-  fmt::SystemError error("", 0);
-  try {
-    throw_error(error_code, "test {}") << "error";
-  } catch (const fmt::SystemError &e) {
-    error = e;
-  }
-  fmt::Writer message;
-  format(message, error_code, "test error");
-  EXPECT_EQ(str(message), error.what());
-  EXPECT_EQ(error_code, error.error_code());
-}
-
-TEST(UtilTest, FormatSystemErrorMessage) {
-  fmt::Writer message;
-  fmt::internal::FormatSystemErrorMessage(message, EDOM, "test");
-  EXPECT_EQ(str(fmt::Format("test: {}")
-    << GetSystemErrorMessage(EDOM)), fmt::str(message));
-}
-
-TEST(UtilTest, SystemErrorSink) {
-  CheckErrorSink<fmt::SystemErrorSink>(
-      EDOM, fmt::internal::FormatSystemErrorMessage);
-}
-
-TEST(UtilTest, ThrowSystemError) {
-  CheckThrowError(EDOM,
-      fmt::internal::FormatSystemErrorMessage, fmt::ThrowSystemError);
-}
-
-TEST(ErrorTest, ReportSystemError) {
-  fmt::Writer out;
-  fmt::internal::FormatSystemErrorMessage(out, EDOM, "test error");
-  out << '\n';
-  EXPECT_WRITE(stderr, fmt::ReportSystemError(EDOM, "test error"), out.str());
-}
-
-#ifdef _WIN32
-
-TEST(UtilTest, FormatWinErrorMessage) {
-  LPWSTR message = 0;
-  FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, 0,
-      ERROR_FILE_EXISTS, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-      reinterpret_cast<LPWSTR>(&message), 0, 0);
-  fmt::internal::UTF16ToUTF8 utf8_message(message);
-  LocalFree(message);
-  fmt::Writer actual_message;
-  fmt::internal::FormatWinErrorMessage(
-      actual_message, ERROR_FILE_EXISTS, "test");
-  EXPECT_EQ(str(fmt::Format("test: {}") << fmt::str(utf8_message)),
-      fmt::str(actual_message));
-}
-
-TEST(UtilTest, WinErrorSink) {
-  CheckErrorSink<fmt::WinErrorSink>(
-      ERROR_FILE_EXISTS, fmt::internal::FormatWinErrorMessage);
-}
-
-TEST(UtilTest, ThrowWinError) {
-  CheckThrowError(ERROR_FILE_EXISTS,
-      fmt::internal::FormatWinErrorMessage, fmt::ThrowWinError);
-}
-
-TEST(ErrorTest, ReportWinError) {
-  fmt::Writer out;
-  fmt::internal::FormatWinErrorMessage(out, ERROR_FILE_EXISTS, "test error");
-  out << '\n';
-  EXPECT_WRITE(stderr,
-      fmt::ReportWinError(ERROR_FILE_EXISTS, "test error"), out.str());
-}
-
-#endif  // _WIN32
 
 class TestString {
  private:
@@ -849,18 +616,15 @@ TEST(FormatterTest, ArgErrors) {
       "argument index is out of range in format");
 
   char format[BUFFER_SIZE];
-  SPrintf(format, "{%u", UINT_MAX);
+  SPrintf(format, "{%u", INT_MAX);
   EXPECT_THROW_MSG(Format(format), FormatError, "unmatched '{' in format");
-  SPrintf(format, "{%u}", UINT_MAX);
+  SPrintf(format, "{%u}", INT_MAX);
   EXPECT_THROW_MSG(Format(format), FormatError,
       "argument index is out of range in format");
 
-  SPrintf(format, "{%u", UINT_MAX);
-  Increment(format + 1);
+  SPrintf(format, "{%u", INT_MAX + 1u);
   EXPECT_THROW_MSG(Format(format), FormatError, "unmatched '{' in format");
-  std::size_t size = std::strlen(format);
-  format[size] = '}';
-  format[size + 1] = 0;
+  SPrintf(format, "{%u}", INT_MAX + 1u);
   EXPECT_THROW_MSG(Format(format), FormatError, "number is too big in format");
 }
 
diff --git a/test/printf-test.cc b/test/printf-test.cc
new file mode 100644
index 00000000..18b682d7
--- /dev/null
+++ b/test/printf-test.cc
@@ -0,0 +1,144 @@
+/*
+ printf tests.
+
+ Copyright (c) 2012-2014, 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 <climits>
+#include <cstring>
+
+#include "format.h"
+#include "gtest-extra.h"
+#include "util.h"
+
+#if FMT_USE_VARIADIC_TEMPLATES && FMT_USE_RVALUE_REFERENCES
+
+using fmt::Format;
+using fmt::FormatError;
+
+// Returns a number UINT_MAX + 1 formatted as a string.
+std::string GetBigNumber() {
+  char format[BUFFER_SIZE];
+  sprintf(format, "%u", UINT_MAX);
+  Increment(format + 1);
+  return format;
+}
+
+const unsigned BIG_NUM = INT_MAX + 1u;
+
+TEST(PrintfTest, NoArgs) {
+  EXPECT_EQ("test", str(fmt::sprintf("test")));
+}
+
+TEST(PrintfTest, Escape) {
+  EXPECT_EQ("%", str(fmt::sprintf("%%")));
+  EXPECT_EQ("before %", str(fmt::sprintf("before %%")));
+  EXPECT_EQ("% after", str(fmt::sprintf("%% after")));
+  EXPECT_EQ("before % after", str(fmt::sprintf("before %% after")));
+  EXPECT_EQ("%s", str(fmt::sprintf("%%s")));
+}
+
+TEST(PrintfTest, PositionalArgs) {
+  EXPECT_EQ("42", str(fmt::sprintf("%1$d", 42)));
+  EXPECT_EQ("before 42", str(fmt::sprintf("before %1$d", 42)));
+  EXPECT_EQ("42 after", str(fmt::sprintf("%1$d after",42)));
+  EXPECT_EQ("before 42 after", str(fmt::sprintf("before %1$d after", 42)));
+  EXPECT_EQ("answer = 42", str(fmt::sprintf("%1$s = %2$d", "answer", 42)));
+  EXPECT_EQ("42 is the answer",
+      str(fmt::sprintf("%2$d is the %1$s", "answer", 42)));
+  EXPECT_EQ("abracadabra", str(fmt::sprintf("%1$s%2$s%1$s", "abra", "cad")));
+}
+
+TEST(PrintfTest, AutomaticArgIndexing) {
+  EXPECT_EQ("abc", str(fmt::sprintf("%c%c%c", 'a', 'b', 'c')));
+}
+
+TEST(PrintfTest, NumberIsTooBigInArgIndex) {
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%{}$", BIG_NUM))),
+      FormatError, "invalid format string");
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%{}$d", BIG_NUM))),
+      FormatError, "number is too big in format");
+}
+
+TEST(PrintfTest, SwitchArgIndexing) {
+  EXPECT_THROW_MSG(fmt::sprintf("%1$d%", 1, 2),
+      FormatError, "invalid format string");
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%1$d%{}d", BIG_NUM)), 1, 2),
+      FormatError, "cannot switch from manual to automatic argument indexing");
+  EXPECT_THROW_MSG(fmt::sprintf("%1$d%d", 1, 2),
+      FormatError, "cannot switch from manual to automatic argument indexing");
+
+  EXPECT_THROW_MSG(fmt::sprintf("%d%1$", 1, 2),
+      FormatError, "invalid format string");
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%d%{}$d", BIG_NUM)), 1, 2),
+      FormatError, "number is too big in format");
+  EXPECT_THROW_MSG(fmt::sprintf("%d%1$d", 1, 2),
+      FormatError, "cannot switch from automatic to manual argument indexing");
+
+  // Indexing errors override width errors.
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%d%1${}d", BIG_NUM)), 1, 2),
+      FormatError, "cannot switch from automatic to manual argument indexing");
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%1$d%{}d", BIG_NUM)), 1, 2),
+      FormatError, "cannot switch from manual to automatic argument indexing");
+}
+
+TEST(PrintfTest, InvalidArgIndex) {
+  EXPECT_THROW_MSG(fmt::sprintf("%0$d", 42), FormatError,
+      "argument index is out of range in format");
+  EXPECT_THROW_MSG(fmt::sprintf("%2$d", 42), FormatError,
+      "argument index is out of range in format");
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%{}$d", INT_MAX)), 42),
+      FormatError, "argument index is out of range in format");
+
+  EXPECT_THROW_MSG(fmt::sprintf("%2$", 42),
+      FormatError, "invalid format string");
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%{}$d", BIG_NUM)), 42),
+      FormatError, "number is too big in format");
+}
+
+TEST(PrintfTest, Width) {
+  EXPECT_EQ("  abc", str(fmt::sprintf("%5s", "abc")));
+  EXPECT_EQ("  abc", str(fmt::sprintf("%1$5s", "abc")));
+
+  // Width cannot be specified twice.
+  EXPECT_THROW_MSG(fmt::sprintf("%5-5d", 42), FormatError,
+      "unknown format code '-' for integer");
+}
+
+TEST(PrintfTest, InvalidWidth) {
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%{}d", BIG_NUM)), 42),
+      FormatError, "number is too big in format");
+  EXPECT_THROW_MSG(fmt::sprintf(str(Format("%1${}d", BIG_NUM)), 42),
+      FormatError, "number is too big in format");
+}
+
+// TODO
+
+TEST(PrintfTest, Align) {
+  EXPECT_EQ("  abc", str(fmt::sprintf("%5s", "abc")));
+  EXPECT_EQ("abc  ", str(fmt::sprintf("%-5s", "abc")));
+}
+
+#endif
+
diff --git a/test/util-test.cc b/test/util-test.cc
new file mode 100644
index 00000000..bb89a97e
--- /dev/null
+++ b/test/util-test.cc
@@ -0,0 +1,256 @@
+/*
+ Utility tests.
+
+ Copyright (c) 2012-2014, 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 <cstring>
+#include "gtest-extra.h"
+#include "format.h"
+#include "util.h"
+
+using fmt::StringRef;
+
+namespace {
+std::string GetSystemErrorMessage(int error_code) {
+#ifndef _WIN32
+  return strerror(error_code);
+#else
+  enum { BUFFER_SIZE = 200 };
+  char buffer[BUFFER_SIZE];
+  EXPECT_EQ(0, strerror_s(buffer, BUFFER_SIZE, error_code));
+  std::size_t max_len = BUFFER_SIZE - 1;
+  EXPECT_LT(std::strlen(buffer), max_len);
+  return buffer;
+#endif
+}
+}
+
+TEST(UtilTest, Increment) {
+  char s[10] = "123";
+  Increment(s);
+  EXPECT_STREQ("124", s);
+  s[2] = '8';
+  Increment(s);
+  EXPECT_STREQ("129", s);
+  Increment(s);
+  EXPECT_STREQ("130", s);
+  s[1] = s[2] = '9';
+  Increment(s);
+  EXPECT_STREQ("200", s);
+}
+
+// Tests fmt::internal::CountDigits for integer type Int.
+template <typename Int>
+void TestCountDigits(Int) {
+  for (Int i = 0; i < 10; ++i)
+          EXPECT_EQ(1u, fmt::internal::CountDigits(i));
+  for (Int i = 1, n = 1,
+               end = std::numeric_limits<Int>::max() / 10; n <= end; ++i) {
+    n *= 10;
+    EXPECT_EQ(i, fmt::internal::CountDigits(n - 1));
+    EXPECT_EQ(i + 1, fmt::internal::CountDigits(n));
+  }
+}
+
+TEST(UtilTest, CountDigits) {
+  TestCountDigits(uint32_t());
+  TestCountDigits(uint64_t());
+}
+
+#ifdef _WIN32
+TEST(UtilTest, UTF16ToUTF8) {
+  std::string s = "ёжик";
+  fmt::internal::UTF16ToUTF8 u(L"\x0451\x0436\x0438\x043A");
+  EXPECT_EQ(s, fmt::str(u));
+  EXPECT_EQ(s.size(), u.size());
+}
+
+TEST(UtilTest, UTF8ToUTF16) {
+  std::string s = "лошадка";
+  fmt::internal::UTF8ToUTF16 u(s.c_str());
+  EXPECT_EQ(L"\x043B\x043E\x0448\x0430\x0434\x043A\x0430", fmt::str(u));
+  EXPECT_EQ(7, u.size());
+}
+
+template <typename Converter>
+void CheckUTFConversionError(const char *message) {
+  fmt::Writer out;
+  fmt::internal::FormatWinErrorMessage(out, ERROR_INVALID_PARAMETER, message);
+  fmt::SystemError error("", 0);
+  try {
+    Converter(0);
+  } catch (const fmt::SystemError &e) {
+    error = e;
+  }
+  EXPECT_EQ(ERROR_INVALID_PARAMETER, error.error_code());
+  EXPECT_EQ(out.str(), error.what());
+}
+
+TEST(UtilTest, UTF16ToUTF8Error) {
+  CheckUTFConversionError<fmt::internal::UTF16ToUTF8>(
+      "cannot convert string from UTF-16 to UTF-8");
+}
+
+TEST(UtilTest, UTF8ToUTF16Error) {
+  CheckUTFConversionError<fmt::internal::UTF8ToUTF16>(
+      "cannot convert string from UTF-8 to UTF-16");
+}
+
+TEST(UtilTest, UTF16ToUTF8Convert) {
+  fmt::internal::UTF16ToUTF8 u;
+  EXPECT_EQ(ERROR_INVALID_PARAMETER, u.Convert(0));
+}
+#endif  // _WIN32
+
+TEST(UtilTest, StrError) {
+  using fmt::internal::StrError;
+  char *message = 0;
+  char buffer[BUFFER_SIZE];
+#ifndef NDEBUG
+  EXPECT_DEBUG_DEATH(StrError(EDOM, message = 0, 0), "Assertion");
+  EXPECT_DEBUG_DEATH(StrError(EDOM, message = buffer, 0), "Assertion");
+#endif
+  buffer[0] = 'x';
+#ifdef _GNU_SOURCE
+  // Use invalid error code to make sure that StrError returns an error
+  // message in the buffer rather than a pointer to a static string.
+  int error_code = -1;
+#else
+  int error_code = EDOM;
+#endif
+  int result = StrError(error_code, message = buffer, 1);
+  EXPECT_EQ(buffer, message);  // Message should point to buffer.
+  EXPECT_EQ(ERANGE, result);
+  EXPECT_STREQ("", message);
+  result = StrError(error_code, message = buffer, BUFFER_SIZE);
+  EXPECT_EQ(0, result);
+  std::size_t message_size = std::strlen(message);
+  EXPECT_GE(BUFFER_SIZE - 1u, message_size);
+  EXPECT_EQ(GetSystemErrorMessage(error_code), message);
+  result = StrError(error_code, message = buffer, message_size);
+  EXPECT_EQ(ERANGE, result);
+}
+
+TEST(UtilTest, SystemError) {
+  fmt::SystemError e(StringRef("test"), 42);
+  EXPECT_STREQ("test", e.what());
+  EXPECT_EQ(42, e.error_code());
+}
+
+typedef void (*FormatErrorMessage)(
+        fmt::Writer &out, int error_code, StringRef message);
+
+template <typename Sink>
+void CheckErrorSink(int error_code, FormatErrorMessage format) {
+  fmt::SystemError error("", 0);
+  Sink sink(error_code);
+  fmt::Writer w;
+  w << "test";
+  try {
+    sink(w);
+  } catch (const fmt::SystemError &e) {
+    error = e;
+  }
+  fmt::Writer message;
+  format(message, error_code, "test");
+  EXPECT_EQ(str(message), error.what());
+  EXPECT_EQ(error_code, error.error_code());
+}
+
+template <typename Sink>
+void CheckThrowError(int error_code, FormatErrorMessage format,
+        fmt::Formatter<Sink> (*throw_error)(int error_code, StringRef format)) {
+  fmt::SystemError error("", 0);
+  try {
+    throw_error(error_code, "test {}") << "error";
+  } catch (const fmt::SystemError &e) {
+    error = e;
+  }
+  fmt::Writer message;
+  format(message, error_code, "test error");
+  EXPECT_EQ(str(message), error.what());
+  EXPECT_EQ(error_code, error.error_code());
+}
+
+TEST(UtilTest, FormatSystemErrorMessage) {
+  fmt::Writer message;
+  fmt::internal::FormatSystemErrorMessage(message, EDOM, "test");
+  EXPECT_EQ(str(fmt::Format("test: {}")
+          << GetSystemErrorMessage(EDOM)), fmt::str(message));
+}
+
+TEST(UtilTest, SystemErrorSink) {
+  CheckErrorSink<fmt::SystemErrorSink>(
+          EDOM, fmt::internal::FormatSystemErrorMessage);
+}
+
+TEST(UtilTest, ThrowSystemError) {
+  CheckThrowError(EDOM,
+          fmt::internal::FormatSystemErrorMessage, fmt::ThrowSystemError);
+}
+
+TEST(UtilTest, ReportSystemError) {
+  fmt::Writer out;
+  fmt::internal::FormatSystemErrorMessage(out, EDOM, "test error");
+  out << '\n';
+  EXPECT_WRITE(stderr, fmt::ReportSystemError(EDOM, "test error"), out.str());
+}
+
+#ifdef _WIN32
+
+TEST(UtilTest, FormatWinErrorMessage) {
+  LPWSTR message = 0;
+  FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, 0,
+      ERROR_FILE_EXISTS, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+      reinterpret_cast<LPWSTR>(&message), 0, 0);
+  fmt::internal::UTF16ToUTF8 utf8_message(message);
+  LocalFree(message);
+  fmt::Writer actual_message;
+  fmt::internal::FormatWinErrorMessage(
+      actual_message, ERROR_FILE_EXISTS, "test");
+  EXPECT_EQ(str(fmt::Format("test: {}") << fmt::str(utf8_message)),
+      fmt::str(actual_message));
+}
+
+TEST(UtilTest, WinErrorSink) {
+  CheckErrorSink<fmt::WinErrorSink>(
+      ERROR_FILE_EXISTS, fmt::internal::FormatWinErrorMessage);
+}
+
+TEST(UtilTest, ThrowWinError) {
+  CheckThrowError(ERROR_FILE_EXISTS,
+      fmt::internal::FormatWinErrorMessage, fmt::ThrowWinError);
+}
+
+TEST(UtilTest, ReportWinError) {
+  fmt::Writer out;
+  fmt::internal::FormatWinErrorMessage(out, ERROR_FILE_EXISTS, "test error");
+  out << '\n';
+  EXPECT_WRITE(stderr,
+      fmt::ReportWinError(ERROR_FILE_EXISTS, "test error"), out.str());
+}
+
+#endif  // _WIN32
diff --git a/test/util.cc b/test/util.cc
new file mode 100644
index 00000000..bfcd5a49
--- /dev/null
+++ b/test/util.cc
@@ -0,0 +1,39 @@
+/*
+ Test utilities.
+
+ Copyright (c) 2012-2014, 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 "util.h"
+#include <cstring>
+
+void Increment(char *s) {
+  for (int i = static_cast<int>(std::strlen(s)) - 1; i >= 0; --i) {
+    if (s[i] != '9') {
+      ++s[i];
+      break;
+    }
+    s[i] = '0';
+  }
+}
diff --git a/test/util.h b/test/util.h
new file mode 100644
index 00000000..b94d83b0
--- /dev/null
+++ b/test/util.h
@@ -0,0 +1,31 @@
+/*
+ Test utilities.
+
+ Copyright (c) 2012-2014, 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.
+ */
+
+enum {BUFFER_SIZE = 256};
+
+// Increment a number in a string.
+void Increment(char *s);