Implement formatting of integers.

format.h

@@ -53,7 +53,6 @@ class Formatter {
       struct {
         union {
           const char *string_value;
-          const wchar_t *wstring_value;
           const void *pointer_value;
         };
         std::size_t size;
@@ -74,7 +73,6 @@ class Formatter {
     explicit Arg(char value) : type(CHAR), int_value(value) {}
     explicit Arg(const char *value, std::size_t size = 0)
     : type(STRING), string_value(value), size(size) {}
-    explicit Arg(const wchar_t *value) : type(WSTRING), wstring_value(value) {}
     explicit Arg(const void *value) : type(POINTER), pointer_value(value) {}
     explicit Arg(const void *value, FormatFunc f)
     : type(CUSTOM), custom_value(value), format(f) {}
@@ -92,10 +90,14 @@ class Formatter {
     args_.push_back(arg);
   }
 
-  // Formats an argument of a built-in type, such as "int" or "double".
+  // Formats an integer.
   template <typename T>
-  void FormatBuiltinArg(
-      const char *format, const T &arg, int width, int precision);
+  void FormatInt(T value, unsigned flags, int width, char type);
+
+  // Formats a floating point number.
+  template <typename T>
+  void FormatDouble(
+      T value, unsigned flags, int width, int precision, char type);
 
   // Formats an argument of a custom type, such as a user-defined class.
   template <typename T>
@@ -199,11 +201,6 @@ class ArgFormatter {
     return *this;
   }
 
-  ArgFormatter &operator<<(const wchar_t *value) {
-    formatter_->Add(Formatter::Arg(value));
-    return *this;
-  }
-
   ArgFormatter &operator<<(const std::string &value) {
     formatter_->Add(Formatter::Arg(value.c_str(), value.size()));
     return *this;
@@ -214,10 +211,16 @@ class ArgFormatter {
     return *this;
   }
 
-  // This method is not implemented intentionally to disallow output of
+  // This method contains a deliberate error to disallow formatting
   // arbitrary pointers. If you want to output a pointer cast it to void*.
   template <typename T>
-  ArgFormatter &operator<<(const T *value);
+  ArgFormatter &operator<<(const T *value) {
+    "Formatting arbitrary pointers is not allowed" = value;
+  }
+
+  // This method is not implemented intentionally to disallow formatting
+  // wide characters.
+  ArgFormatter &operator<<(wchar_t value);
 
   template <typename T>
   ArgFormatter &operator<<(T *value) {
@@ -253,13 +256,10 @@ void Formatter::FormatCustomArg(const void *arg, int width) {
   std::ostringstream os;
   os << value;
   std::string str(os.str());
-  if (width < 0) {
-    // Extra char is reserved for terminating '\0'.
-    buffer_.reserve(buffer_.size() + str.size() + 1);
+  buffer_.reserve(buffer_.size() + std::max<std::size_t>(width, str.size()));
   buffer_.insert(buffer_.end(), str.begin(), str.end());
-    return;
-  }
-  FormatBuiltinArg("%-*s", str.c_str(), width, -1);
+  if (width > str.size())
+    buffer_.resize(buffer_.size() + width - str.size(), ' ');
 }
 
 inline ArgFormatter Formatter::operator()(const char *format) {

format_test.cc

@@ -71,7 +71,7 @@ TEST(FormatterTest, NoArgs) {
   EXPECT_EQ("test", str(Format("test")));
 }
 
-TEST(FormatterTest, Args) {
+TEST(FormatterTest, ArgsInDifferentPositions) {
   EXPECT_EQ("42", str(Format("{0}") << 42));
   EXPECT_EQ("before 42", str(Format("before {0}") << 42));
   EXPECT_EQ("42 after", str(Format("{0} after") << 42));
@@ -86,13 +86,13 @@ TEST(FormatterTest, ArgErrors) {
   EXPECT_THROW_MSG(Format("{}"), FormatError,
       "missing argument index in format string");
   EXPECT_THROW_MSG(Format("{0"), FormatError, "unmatched '{' in format");
-  EXPECT_THROW_MSG(Format("{0}"), std::out_of_range,
+  EXPECT_THROW_MSG(Format("{0}"), FormatError,
       "argument index is out of range in format");
   char format[256];
   std::sprintf(format, "{%u", UINT_MAX);
   EXPECT_THROW_MSG(Format(format), FormatError, "unmatched '{' in format");
   std::sprintf(format, "{%u}", UINT_MAX);
-  EXPECT_THROW_MSG(Format(format), std::out_of_range,
+  EXPECT_THROW_MSG(Format(format), FormatError,
       "argument index is out of range in format");
   if (ULONG_MAX > UINT_MAX) {
     std::sprintf(format, "{%lu", UINT_MAX + 1l);
@@ -130,8 +130,6 @@ TEST(FormatterTest, PlusFlag) {
       FormatError, "format specifier '+' requires numeric argument");
   EXPECT_THROW_MSG(Format("{0:+}") << "abc",
       FormatError, "format specifier '+' requires numeric argument");
-  EXPECT_THROW_MSG(Format("{0:+}") << L"abc",
-      FormatError, "format specifier '+' requires numeric argument");
   EXPECT_THROW_MSG(Format("{0:+}") << reinterpret_cast<void*>(0x42),
       FormatError, "format specifier '+' requires numeric argument");
   EXPECT_THROW_MSG(Format("{0:+}") << TestString(),
@@ -152,8 +150,6 @@ TEST(FormatterTest, ZeroFlag) {
       FormatError, "format specifier '0' requires numeric argument");
   EXPECT_THROW_MSG(Format("{0:05}") << "abc",
       FormatError, "format specifier '0' requires numeric argument");
-  EXPECT_THROW_MSG(Format("{0:05}") << L"abc",
-      FormatError, "format specifier '0' requires numeric argument");
   EXPECT_THROW_MSG(Format("{0:05}") << reinterpret_cast<void*>(0x42),
       FormatError, "format specifier '0' requires numeric argument");
   EXPECT_THROW_MSG(Format("{0:05}") << TestString(),
@@ -189,9 +185,8 @@ TEST(FormatterTest, Width) {
   EXPECT_EQ("    0xcafe",
       str(Format("{0:10}") << reinterpret_cast<void*>(0xcafe)));
   EXPECT_EQ("x          ", str(Format("{0:11}") << 'x'));
-  EXPECT_EQ("narrow      ", str(Format("{0:12}") << "narrow"));
-  EXPECT_EQ("wide         ", str(Format("{0:13}") << L"wide"));
-  EXPECT_EQ("test          ", str(Format("{0:14}") << TestString("test")));
+  EXPECT_EQ("str         ", str(Format("{0:12}") << "str"));
+  EXPECT_EQ("test         ", str(Format("{0:13}") << TestString("test")));
 }
 
 TEST(FormatterTest, Precision) {
@@ -224,55 +219,97 @@ TEST(FormatterTest, Precision) {
       FormatError, "unmatched '{' in format");
 
   EXPECT_THROW_MSG(Format("{0:.2}") << 42,
-      FormatError, "precision specifier requires floating-point type");
-  EXPECT_EQ("42.00", str(Format("{0:.2f}") << 42));
+      FormatError, "precision specifier requires floating-point argument");
+  EXPECT_THROW_MSG(Format("{0:.2f}") << 42,
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_THROW_MSG(Format("{0:.2}") << 42u,
-      FormatError, "precision specifier requires floating-point type");
-  EXPECT_EQ("42.00", str(Format("{0:.2f}") << 42u));
+      FormatError, "precision specifier requires floating-point argument");
+  EXPECT_THROW_MSG(Format("{0:.2f}") << 42u,
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_THROW_MSG(Format("{0:.2}") << 42l,
-      FormatError, "precision specifier requires floating-point type");
-  EXPECT_EQ("42.00", str(Format("{0:.2f}") << 42l));
+      FormatError, "precision specifier requires floating-point argument");
+  EXPECT_THROW_MSG(Format("{0:.2f}") << 42l,
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_THROW_MSG(Format("{0:.2}") << 42ul,
-      FormatError, "precision specifier requires floating-point type");
-  EXPECT_EQ("42.00", str(Format("{0:.2f}") << 42ul));
+      FormatError, "precision specifier requires floating-point argument");
+  EXPECT_THROW_MSG(Format("{0:.2f}") << 42ul,
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_EQ("1.2", str(Format("{0:.2}") << 1.2345));
   EXPECT_EQ("1.2", str(Format("{0:.2}") << 1.2345l));
 
   EXPECT_THROW_MSG(Format("{0:.2}") << reinterpret_cast<void*>(0xcafe),
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_THROW_MSG(Format("{0:.2f}") << reinterpret_cast<void*>(0xcafe),
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
 
   EXPECT_THROW_MSG(Format("{0:.2}") << 'x',
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_THROW_MSG(Format("{0:.2f}") << 'x',
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
 
   EXPECT_THROW_MSG(Format("{0:.2}") << "str",
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_THROW_MSG(Format("{0:.2f}") << "str",
-      FormatError, "precision specifier requires floating-point type");
-
-  EXPECT_THROW_MSG(Format("{0:.2}") << L"str",
-      FormatError, "precision specifier requires floating-point type");
-  EXPECT_THROW_MSG(Format("{0:.2f}") << L"str",
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
 
   EXPECT_THROW_MSG(Format("{0:.2}") << TestString(),
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
   EXPECT_THROW_MSG(Format("{0:.2f}") << TestString(),
-      FormatError, "precision specifier requires floating-point type");
+      FormatError, "precision specifier requires floating-point argument");
+}
+
+TEST(FormatterTest, Type) {
+  EXPECT_THROW_MSG(Format("{0:v") << 42,
+      FormatError, "unmatched '{' in format");
+  EXPECT_THROW_MSG(Format("{0:v}") << 42,
+      FormatError, "unknown format code 'v' for integer");
 }
 
-TEST(FormatterTest, FormatInt) {
+TEST(FormatterTest, FormatDec) {
+  EXPECT_EQ("0", str(Format("{0}") << 0));
   EXPECT_EQ("42", str(Format("{0}") << 42));
-  EXPECT_EQ("-1234", str(Format("{0}") << -1234));
-  std::ostringstream os;
-  os << INT_MIN;
-  EXPECT_EQ(os.str(), str(Format("{0}") << INT_MIN));
-  os.str(std::string());
-  os << INT_MAX;
-  EXPECT_EQ(os.str(), str(Format("{0}") << INT_MAX));
+  EXPECT_EQ("42", str(Format("{0:d}") << 42));
+  EXPECT_EQ("42", str(Format("{0}") << 42u));
+  EXPECT_EQ("-42", str(Format("{0}") << -42));
+  EXPECT_EQ("12345", str(Format("{0}") << 12345));
+  EXPECT_EQ("67890", str(Format("{0}") << 67890));
+  char buffer[256];
+  sprintf(buffer, "%d", INT_MIN);
+  EXPECT_EQ(buffer, str(Format("{0}") << INT_MIN));
+  sprintf(buffer, "%d", INT_MAX);
+  EXPECT_EQ(buffer, str(Format("{0}") << INT_MAX));
+  sprintf(buffer, "%u", UINT_MAX);
+  EXPECT_EQ(buffer, str(Format("{0}") << UINT_MAX));
+  sprintf(buffer, "%ld", 0ul - LONG_MIN);
+  EXPECT_EQ(buffer, str(Format("{0}") << LONG_MIN));
+  sprintf(buffer, "%ld", LONG_MAX);
+  EXPECT_EQ(buffer, str(Format("{0}") << LONG_MAX));
+  sprintf(buffer, "%lu", ULONG_MAX);
+  EXPECT_EQ(buffer, str(Format("{0}") << ULONG_MAX));
+}
+
+TEST(FormatterTest, FormatHex) {
+  EXPECT_EQ("0", str(Format("{0:x}") << 0));
+  EXPECT_EQ("42", str(Format("{0:x}") << 0x42));
+  EXPECT_EQ("42", str(Format("{0:x}") << 0x42u));
+  EXPECT_EQ("-42", str(Format("{0:x}") << -0x42));
+  EXPECT_EQ("12345678", str(Format("{0:x}") << 0x12345678));
+  EXPECT_EQ("90abcdef", str(Format("{0:x}") << 0x90abcdef));
+  EXPECT_EQ("12345678", str(Format("{0:X}") << 0x12345678));
+  EXPECT_EQ("90ABCDEF", str(Format("{0:X}") << 0x90ABCDEF));
+  char buffer[256];
+  sprintf(buffer, "-%x", 0u - INT_MIN);
+  EXPECT_EQ(buffer, str(Format("{0:x}") << INT_MIN));
+  sprintf(buffer, "%x", INT_MAX);
+  EXPECT_EQ(buffer, str(Format("{0:x}") << INT_MAX));
+  sprintf(buffer, "%x", UINT_MAX);
+  EXPECT_EQ(buffer, str(Format("{0:x}") << UINT_MAX));
+  sprintf(buffer, "-%lx", 0ul - LONG_MIN);
+  EXPECT_EQ(buffer, str(Format("{0:x}") << LONG_MIN));
+  sprintf(buffer, "%lx", LONG_MAX);
+  EXPECT_EQ(buffer, str(Format("{0:x}") << LONG_MAX));
+  sprintf(buffer, "%lx", ULONG_MAX);
+  EXPECT_EQ(buffer, str(Format("{0:x}") << ULONG_MAX));
 }
 
 TEST(FormatterTest, FormatChar) {
@@ -283,8 +320,25 @@ TEST(FormatterTest, FormatString) {
   EXPECT_EQ("test", str(Format("{0}") << std::string("test")));
 }
 
+TEST(FormatterTest, FormatPointer) {
+  EXPECT_EQ("0x0", str(Format("{0}") << reinterpret_cast<void*>(0)));
+}
+
+class Date {
+  int year_, month_, day_;
+ public:
+  Date(int year, int month, int day) : year_(year), month_(month), day_(day) {}
+
+  friend std::ostream &operator<<(std::ostream &os, const Date &d) {
+    os << d.year_ << '-' << d.month_ << '-' << d.day_;
+    return os;
+  }
+};
+
 TEST(FormatterTest, FormatCustomArg) {
   EXPECT_EQ("a string", str(Format("{0}") << TestString("a string")));
+  std::string s = str(fmt::Format("The date is {0}") << Date(2012, 12, 9));
+  EXPECT_EQ("The date is 2012-12-9", s);
 }
 
 TEST(FormatterTest, FormatStringFromSpeedTest) {