Fix https://github.com/cppformat/cppformat/issues/55.

format.cc

@@ -431,8 +431,18 @@ class fmt::internal::ArgFormatter :
   void visit_any_double(T value) { writer_.FormatDouble(value, spec_); }
 
   void visit_char(int value) {
-    if (spec_.type_ && spec_.type_ != 'c')
+    if (spec_.type_ && spec_.type_ != 'c') {
-      fmt::internal::ReportUnknownType(spec_.type_, "char");
+      switch (spec_.type_) {
+      // TODO: don't duplicate integer format specifiers here
+      case 'd': case 'x': case 'X': case 'b': case 'B': case 'o':
+        writer_.FormatInt(value, spec_);
+        break;
+      default:
+        internal::ReportUnknownType(spec_.type_, "char");
+      }
+    }
+    if (spec_.align_ == ALIGN_NUMERIC || spec_.flags_ != 0)
+      throw FormatError("invalid format specifier for char");
     typedef typename fmt::BasicWriter<Char>::CharPtr CharPtr;
     CharPtr out = CharPtr();
     if (spec_.width_ > 1) {
@@ -893,25 +903,17 @@ void fmt::internal::PrintfFormatter<Char>::Format(
     case Arg::ULONG_LONG:
       writer.FormatInt(arg.ulong_long_value, spec);
       break;
-    case Arg::DOUBLE:
-      writer.FormatDouble(arg.double_value, spec);
-      break;
-    case Arg::LONG_DOUBLE:
-      writer.FormatDouble(arg.long_double_value, spec);
-      break;
     case Arg::CHAR: {
       if (spec.type_ && spec.type_ != 'c')
-        internal::ReportUnknownType(spec.type_, "char");
+        writer.FormatInt(arg.int_value, spec);
       typedef typename BasicWriter<Char>::CharPtr CharPtr;
       CharPtr out = CharPtr();
       if (spec.width_ > 1) {
-        Char fill = static_cast<Char>(spec.fill());
+        Char fill = ' ';
         out = writer.GrowBuffer(spec.width_);
-        if (spec.align_ == ALIGN_RIGHT) {
+        if (spec.align_ != ALIGN_LEFT) {
           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);
         }
@@ -921,6 +923,12 @@ void fmt::internal::PrintfFormatter<Char>::Format(
       *out = static_cast<Char>(arg.int_value);
       break;
     }
+    case Arg::DOUBLE:
+      writer.FormatDouble(arg.double_value, spec);
+      break;
+    case Arg::LONG_DOUBLE:
+      writer.FormatDouble(arg.long_double_value, spec);
+      break;
     case Arg::STRING:
       writer.write_str(arg.string, spec);
       break;
@@ -1001,6 +1009,7 @@ const Char *fmt::BasicFormatter<Char>::format(
         break;
       case '-':
         CheckSign(s, arg);
+        spec.flags_ |= MINUS_FLAG;
         break;
       case ' ':
         CheckSign(s, arg);

format.h

@@ -569,10 +569,10 @@ struct NonZero<0> {
 struct Arg {
   enum Type {
     // Integer types should go first,
-    INT, UINT, LONG_LONG, ULONG_LONG, LAST_INTEGER_TYPE = ULONG_LONG,
+    INT, UINT, LONG_LONG, ULONG_LONG, CHAR, LAST_INTEGER_TYPE = CHAR,
     // followed by floating-point types.
     DOUBLE, LONG_DOUBLE, LAST_NUMERIC_TYPE = LONG_DOUBLE,
-    CHAR, STRING, WSTRING, POINTER, CUSTOM
+    STRING, WSTRING, POINTER, CUSTOM
   };
   Type type;
 
@@ -900,7 +900,7 @@ enum Alignment {
 };
 
 // Flags.
-enum { SIGN_FLAG = 1, PLUS_FLAG = 2, HASH_FLAG = 4 };
+enum { SIGN_FLAG = 1, PLUS_FLAG = 2, MINUS_FLAG = 4, HASH_FLAG = 8 };
 
 // An empty format specifier.
 struct EmptySpec {};

test/format-test.cc

@@ -696,7 +696,7 @@ TEST(FormatterTest, NumericAlign) {
   EXPECT_THROW_MSG(format("{0:=5", 'c'),
       FormatError, "unmatched '{' in format");
   EXPECT_THROW_MSG(format("{0:=5}", 'c'),
-      FormatError, "format specifier '=' requires numeric argument");
+      FormatError, "invalid format specifier for char");
   EXPECT_THROW_MSG(format("{0:=5}", "abc"),
       FormatError, "format specifier '=' requires numeric argument");
   EXPECT_THROW_MSG(format("{0:=8}", reinterpret_cast<void*>(0xface)),
@@ -760,7 +760,7 @@ TEST(FormatterTest, PlusSign) {
   EXPECT_THROW_MSG(format("{0:+", 'c'),
       FormatError, "unmatched '{' in format");
   EXPECT_THROW_MSG(format("{0:+}", 'c'),
-      FormatError, "format specifier '+' requires numeric argument");
+      FormatError, "invalid format specifier for char");
   EXPECT_THROW_MSG(format("{0:+}", "abc"),
       FormatError, "format specifier '+' requires numeric argument");
   EXPECT_THROW_MSG(format("{0:+}", reinterpret_cast<void*>(0x42)),
@@ -786,7 +786,7 @@ TEST(FormatterTest, MinusSign) {
   EXPECT_THROW_MSG(format("{0:-", 'c'),
       FormatError, "unmatched '{' in format");
   EXPECT_THROW_MSG(format("{0:-}", 'c'),
-      FormatError, "format specifier '-' requires numeric argument");
+      FormatError, "invalid format specifier for char");
   EXPECT_THROW_MSG(format("{0:-}", "abc"),
       FormatError, "format specifier '-' requires numeric argument");
   EXPECT_THROW_MSG(format("{0:-}", reinterpret_cast<void*>(0x42)),
@@ -812,7 +812,7 @@ TEST(FormatterTest, SpaceSign) {
   EXPECT_THROW_MSG(format("{0: ", 'c'),
       FormatError, "unmatched '{' in format");
   EXPECT_THROW_MSG(format("{0: }", 'c'),
-      FormatError, "format specifier ' ' requires numeric argument");
+      FormatError, "invalid format specifier for char");
   EXPECT_THROW_MSG(format("{0: }", "abc"),
       FormatError, "format specifier ' ' requires numeric argument");
   EXPECT_THROW_MSG(format("{0: }", reinterpret_cast<void*>(0x42)),
@@ -859,7 +859,7 @@ TEST(FormatterTest, HashFlag) {
   EXPECT_THROW_MSG(format("{0:#", 'c'),
       FormatError, "unmatched '{' in format");
   EXPECT_THROW_MSG(format("{0:#}", 'c'),
-      FormatError, "format specifier '#' requires numeric argument");
+      FormatError, "invalid format specifier for char");
   EXPECT_THROW_MSG(format("{0:#}", "abc"),
       FormatError, "format specifier '#' requires numeric argument");
   EXPECT_THROW_MSG(format("{0:#}", reinterpret_cast<void*>(0x42)),
@@ -881,7 +881,7 @@ TEST(FormatterTest, ZeroFlag) {
   EXPECT_THROW_MSG(format("{0:0", 'c'),
       FormatError, "unmatched '{' in format");
   EXPECT_THROW_MSG(format("{0:05}", 'c'),
-      FormatError, "format specifier '0' requires numeric argument");
+      FormatError, "invalid format specifier for char");
   EXPECT_THROW_MSG(format("{0:05}", "abc"),
       FormatError, "format specifier '0' requires numeric argument");
   EXPECT_THROW_MSG(format("{0:05}", reinterpret_cast<void*>(0x42)),
@@ -1268,7 +1268,7 @@ TEST(FormatterTest, FormatLongDouble) {
 }
 
 TEST(FormatterTest, FormatChar) {
-  CheckUnknownTypes('a', "c", "char");
+  CheckUnknownTypes('a', "cbBdoxX", "char");
   EXPECT_EQ("a", format("{0}", 'a'));
   EXPECT_EQ("z", format("{0:c}", 'z'));
   EXPECT_EQ(L"a", format(L"{0}", 'a'));