Implement right alignment.

format.cc

@@ -119,15 +119,15 @@ char *Formatter::PrepareFilledBuffer(
     *p = sign;
     p += size;
     std::fill(p, end, spec.fill);
-  } else if (spec.align == ALIGN_NUMERIC) {
-    if (sign) {
-      *p++ = sign;
-      --size;
-    }
-    std::fill(p, end - size, spec.fill);
-    p = end;
   } else {
-    *(end - size) = sign;
+    if (spec.align == ALIGN_NUMERIC) {
+      if (sign) {
+        *p++ = sign;
+        --size;
+      }
+    } else {
+      *(end - size) = sign;
+    }
     std::fill(p, end - size, spec.fill);
     p = end;
   }
@@ -270,6 +270,21 @@ void Formatter::FormatDouble(T value, const FormatSpec &spec, int precision) {
   }
 }
 
+void Formatter::FormatString(
+    const char *s, std::size_t size, const FormatSpec &spec) {
+  char *out = 0;
+  if (spec.width > size) {
+    out = GrowBuffer(spec.width);
+    if (spec.align == ALIGN_RIGHT)
+      out = std::fill_n(out, spec.width - size, spec.fill);
+    else
+      std::fill_n(out + size, spec.width - size, spec.fill);
+  } else {
+    out = GrowBuffer(size);
+  }
+  std::copy(s, s + size, out);
+}
+
 // 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.
 unsigned Formatter::ParseUInt(const char *&s) const {
@@ -455,10 +470,17 @@ void Formatter::DoFormat() {
     case CHAR: {
       if (spec.type && spec.type != 'c')
         ReportUnknownType(spec.type, "char");
-      char *out = GrowBuffer(std::max(spec.width, 1u));
-      *out++ = arg.int_value;
-      if (spec.width > 1)
-        std::fill_n(out, spec.width - 1, spec.fill);
+      char *out = 0;
+      if (spec.width > 1) {
+        out = GrowBuffer(spec.width);
+        if (spec.align == ALIGN_RIGHT)
+          out = std::fill_n(out, spec.width - 1, spec.fill);
+        else
+          std::fill_n(out + 1, spec.width - 1, spec.fill);
+      } else {
+        out = GrowBuffer(1);
+      }
+      *out = arg.int_value;
       break;
     }
     case STRING: {
@@ -472,10 +494,7 @@ void Formatter::DoFormat() {
         if (*str)
           size = std::strlen(str);
       }
-      char *out = GrowBuffer(std::max<size_t>(spec.width, size));
-      out = std::copy(str, str + size, out);
-      if (spec.width > size)
-        std::fill_n(out, spec.width - size, spec.fill);
+      FormatString(str, size, spec);
       break;
     }
     case POINTER:
@@ -498,10 +517,3 @@ void Formatter::DoFormat() {
   buffer_.append(start, s + 1);
   buffer_.resize(buffer_.size() - 1);  // Don't count the terminating zero.
 }
-
-void Formatter::Write(const std::string &s, const FormatSpec &spec) {
-  char *out = GrowBuffer(std::max<std::size_t>(spec.width, s.size()));
-  std::copy(s.begin(), s.end(), out);
-  if (spec.width > s.size())
-    std::fill_n(out + s.size(), spec.width - s.size(), spec.fill);
-}

format.h

@@ -281,6 +281,8 @@ class Formatter {
   template <typename T>
   void FormatDouble(T value, const FormatSpec &spec, int precision);
 
+  void FormatString(const char *s, std::size_t size, const FormatSpec &spec);
+
   // Formats an argument of a custom type, such as a user-defined class.
   template <typename T>
   void FormatCustomArg(const void *arg, const FormatSpec &spec);
@@ -323,10 +325,6 @@ class Formatter {
   const char *c_str() const { return &buffer_[0]; }
 
   std::string str() const { return std::string(&buffer_[0], buffer_.size()); }
-
-  // Writes a string to the output buffer padding with spaces if
-  // necessary to achieve the desired width.
-  void Write(const std::string &s, const FormatSpec &spec);
 };
 
 // A reference to a string. It can be constructed from a C string,
@@ -464,7 +462,7 @@ class ArgFormatter {
   explicit ArgFormatter(Formatter &f) : formatter_(f) {}
 
   void Write(const std::string &s, const FormatSpec &spec) {
-    formatter_.Write(s, spec);
+    formatter_.FormatString(s.data(), s.size(), spec);
   }
 };
 

format_test.cc

@@ -276,6 +276,23 @@ TEST(FormatterTest, LeftAlign) {
   EXPECT_EQ("def  ", str(Format("{0:<5}") << TestString("def")));
 }
 
+TEST(FormatterTest, RightAlign) {
+  EXPECT_EQ("  42", str(Format("{0:>4}") << 42));
+  EXPECT_EQ("  42", str(Format("{0:>4o}") << 042));
+  EXPECT_EQ("  42", str(Format("{0:>4x}") << 0x42));
+  EXPECT_EQ("  -42", str(Format("{0:>5}") << -42));
+  EXPECT_EQ("   42", str(Format("{0:>5}") << 42u));
+  EXPECT_EQ("  -42", str(Format("{0:>5}") << -42l));
+  EXPECT_EQ("   42", str(Format("{0:>5}") << 42ul));
+  EXPECT_EQ("  -42", str(Format("{0:>5}") << -42.0));
+  EXPECT_EQ("  -42", str(Format("{0:>5}") << -42.0l));
+  EXPECT_EQ("    c", str(Format("{0:>5}") << 'c'));
+  EXPECT_EQ("  abc", str(Format("{0:>5}") << "abc"));
+  EXPECT_EQ("  0xface",
+      str(Format("{0:>8}") << reinterpret_cast<void*>(0xface)));
+  EXPECT_EQ("  def", str(Format("{0:>5}") << TestString("def")));
+}
+
 TEST(FormatterTest, Fill) {
   EXPECT_EQ("**42", str(Format("{0:*>4}") << 42));
   EXPECT_EQ("**-42", str(Format("{0:*>5}") << -42));
@@ -662,20 +679,6 @@ TEST(FormatterTest, FormatString) {
   EXPECT_EQ("test", str(Format("{0}") << std::string("test")));
 }
 
-TEST(FormatterTest, Write) {
-  Formatter format;
-  fmt::FormatSpec spec;
-  spec.width = 2;
-  format.Write("12", spec);
-  EXPECT_EQ("12", format.str());
-  spec.width = 4;
-  format.Write("34", spec);
-  EXPECT_EQ("1234  ", format.str());
-  spec.width = 0;
-  format.Write("56", spec);
-  EXPECT_EQ("1234  56", format.str());
-}
-
 TEST(ArgFormatterTest, Write) {
   Formatter formatter;
   fmt::ArgFormatter format(formatter);