Add support for types other than int in oct, hex, hexu & pad. Document the API.

doc/format.rst

@@ -13,7 +13,8 @@ String Formatting
 .. doxygenclass:: format::TempFormatter
    :members:
 
-.. doxygenstruct:: format::NoAction
+.. doxygenclass:: format::NoAction
+   :members:
 
 .. doxygenclass:: format::StringRef
    :members:

format.h

@@ -117,23 +117,36 @@ void Array<T, SIZE>::append(const T *begin, const T *end) {
 }
 
 // Information about an integer type.
+// IntTraits is not specialized for integer types smaller than int,
+// since these are promoted to int.
 template <typename T>
-struct IntTraits {
+struct IntTraits {};
+
+template <typename T, typename UnsignedT>
+struct SignedIntTraits {
+  typedef T Type;
+  typedef UnsignedT UnsignedType;
+  static bool IsNegative(T value) { return value < 0; }
+};
+
+template <typename T>
+struct UnsignedIntTraits {
+  typedef T Type;
   typedef T UnsignedType;
   static bool IsNegative(T) { return false; }
 };
 
 template <>
-struct IntTraits<int> {
-  typedef unsigned UnsignedType;
-  static bool IsNegative(int value) { return value < 0; }
-};
+struct IntTraits<int> : SignedIntTraits<int, unsigned> {};
 
 template <>
-struct IntTraits<long> {
-  typedef unsigned long UnsignedType;
-  static bool IsNegative(long value) { return value < 0; }
-};
+struct IntTraits<unsigned> : UnsignedIntTraits<unsigned> {};
+
+template <>
+struct IntTraits<long> : SignedIntTraits<long, unsigned long> {};
+
+template <>
+struct IntTraits<unsigned long> : UnsignedIntTraits<unsigned long> {};
 
 class ArgInserter;
 }
@@ -157,13 +170,31 @@ class StringRef {
   mutable std::size_t size_;
 
  public:
+  /**
+    Constructs a string reference object from a C string and a size.
+    If `size` is zero, which is the default, the size is computed with
+    `strlen`.
+   */
   StringRef(const char *s, std::size_t size = 0) : data_(s), size_(size) {}
+
+  /**
+    Constructs a string reference from an `std::string` object.
+   */
   StringRef(const std::string &s) : data_(s.c_str()), size_(s.size()) {}
 
+  /**
+    Converts a string reference to an `std::string` object.
+   */
   operator std::string() const { return std::string(data_, size()); }
 
+  /**
+    Returns the pointer to a C string.
+   */
   const char *c_str() const { return data_; }
 
+  /**
+    Returns the string size.
+   */
   std::size_t size() const {
     if (size_ == 0) size_ = std::strlen(data_);
     return size_;
@@ -256,28 +287,39 @@ class IntFormatter : public SpecT {
   T value() const { return value_; }
 };
 
-inline IntFormatter<int, TypeSpec<'o'> > oct(int value) {
-  return IntFormatter<int, TypeSpec<'o'> >(value, TypeSpec<'o'>());
+// internal::IntTraits<T>::Type is used instead of T to avoid instantiating
+// the function for types smaller than int similarly to enable_if.
+template <typename T>
+inline IntFormatter<
+    typename internal::IntTraits<T>::Type, TypeSpec<'o'> > oct(T value) {
+  return IntFormatter<T, TypeSpec<'o'> >(value, TypeSpec<'o'>());
 }
 
-inline IntFormatter<int, TypeSpec<'x'> > hex(int value) {
-  return IntFormatter<int, TypeSpec<'x'> >(value, TypeSpec<'x'>());
+template <typename T>
+inline IntFormatter<
+    typename internal::IntTraits<T>::Type, TypeSpec<'x'> > hex(T value) {
+  return IntFormatter<T, TypeSpec<'x'> >(value, TypeSpec<'x'>());
 }
 
-inline IntFormatter<int, TypeSpec<'X'> > hexu(int value) {
-  return IntFormatter<int, TypeSpec<'X'> >(value, TypeSpec<'X'>());
+template <typename T>
+inline IntFormatter<
+    typename internal::IntTraits<T>::Type, TypeSpec<'X'> > hexu(T value) {
+  return IntFormatter<T, TypeSpec<'X'> >(value, TypeSpec<'X'>());
 }
 
-template <char TYPE>
-inline IntFormatter<int, AlignTypeSpec<TYPE> > pad(
-    IntFormatter<int, TypeSpec<TYPE> > f, unsigned width, char fill = ' ') {
-  return IntFormatter<int, AlignTypeSpec<TYPE> >(
+template <typename T, char TYPE>
+inline IntFormatter<
+    typename internal::IntTraits<T>::Type, AlignTypeSpec<TYPE> > pad(
+    IntFormatter<T, TypeSpec<TYPE> > f, unsigned width, char fill = ' ') {
+  return IntFormatter<T, AlignTypeSpec<TYPE> >(
       f.value(), AlignTypeSpec<TYPE>(width, fill));
 }
 
-inline IntFormatter<int, AlignTypeSpec<0> > pad(
-    int value, unsigned width, char fill = ' ') {
-  return IntFormatter<int, AlignTypeSpec<0> >(
+template <typename T>
+inline IntFormatter<
+    typename internal::IntTraits<T>::Type, AlignTypeSpec<0> > pad(
+    T value, unsigned width, char fill = ' ') {
+  return IntFormatter<T, AlignTypeSpec<0> >(
       value, AlignTypeSpec<0>(width, fill));
 }
 
@@ -336,25 +378,19 @@ class BasicFormatter {
 
  public:
   /**
-    \rst
     Returns the number of characters written to the output buffer.
-    \endrst
    */
   std::size_t size() const { return buffer_.size(); }
 
   /**
-    \rst
     Returns a pointer to the output buffer content. No terminating null
     character is appended.
-    \endrst
    */
   const char *data() const { return &buffer_[0]; }
 
   /**
-    \rst
     Returns a pointer to the output buffer content with terminating null
     character appended.
-    \endrst
    */
   const char *c_str() const {
     std::size_t size = buffer_.size();
@@ -364,9 +400,7 @@ class BasicFormatter {
   }
 
   /**
-    \rst
-    Returns the content of the output buffer as an ``std::string``.
-    \endrst
+    Returns the content of the output buffer as an `std::string`.
    */
   std::string str() const { return std::string(&buffer_[0], buffer_.size()); }
 
@@ -628,18 +662,14 @@ class Formatter : public BasicFormatter {
 
  public:
   /**
-    \rst
     Constructs a formatter with an empty output buffer.
-    \endrst
    */
   Formatter() : format_(0) {}
 
   /**
-    \rst
     Formats a string appending the output to the internal buffer.
-    Arguments are accepted through the returned ``ArgInserter`` object
-    using inserter operator ``<<``.
-    \endrst
+    Arguments are accepted through the returned `ArgInserter` object
+    using inserter operator `<<`.
   */
   internal::ArgInserter operator()(StringRef format);
 };
@@ -764,17 +794,16 @@ inline internal::ArgInserter Formatter::operator()(StringRef format) {
 /**
   A formatting action that does nothing.
  */
-struct NoAction {
+class NoAction {
+ public:
   /** Does nothing. */
   void operator()(const Formatter &) const {}
 };
 
 /**
-  \rst
   A formatter with an action performed when formatting is complete.
   Objects of this class normally exist only as temporaries returned
   by one of the formatting functions which explains the name.
-  \endrst
  */
 template <typename Action = NoAction>
 class TempFormatter : public internal::ArgInserter {

format_test.cc

@@ -1065,21 +1065,29 @@ TEST(TempFormatterTest, Examples) {
 }
 
 TEST(StrTest, oct) {
-  BasicFormatter f;
-  f << oct(042);
-  EXPECT_EQ("42", f.str());
+  EXPECT_EQ("12", (BasicFormatter() << oct(012)).str());
+  EXPECT_EQ("34", (BasicFormatter() << oct(034)).str());
+  EXPECT_EQ("56", (BasicFormatter() << oct(056)).str());
+  EXPECT_EQ("70", (BasicFormatter() << oct(070)).str());
 }
 
 TEST(StrTest, hex) {
-  BasicFormatter f;
-  f << hex(0xbeef);
-  EXPECT_EQ("beef", f.str());
+  fmt::IntFormatter<int, fmt::TypeSpec<'x'> > (*phex)(int value) = hex;
+  phex(42);
+  // This shouldn't compile:
+  //fmt::IntFormatter<short, fmt::TypeSpec<'x'> > (*phex2)(short value) = hex;
+
+  EXPECT_EQ("cafe", (BasicFormatter() << hex(0xcafe)).str());
+  EXPECT_EQ("babe", (BasicFormatter() << hex(0xbabeu)).str());
+  EXPECT_EQ("dead", (BasicFormatter() << hex(0xdeadl)).str());
+  EXPECT_EQ("beef", (BasicFormatter() << hex(0xbeeful)).str());
 }
 
 TEST(StrTest, hexu) {
-  BasicFormatter f;
-  f << hexu(0xbabe);
-  EXPECT_EQ("BABE", f.str());
+  EXPECT_EQ("CAFE", (BasicFormatter() << hexu(0xcafe)).str());
+  EXPECT_EQ("BABE", (BasicFormatter() << hexu(0xbabeu)).str());
+  EXPECT_EQ("DEAD", (BasicFormatter() << hexu(0xdeadl)).str());
+  EXPECT_EQ("BEEF", (BasicFormatter() << hexu(0xbeeful)).str());
 }
 
 class ISO8601DateFormatter {
@@ -1098,9 +1106,17 @@ public:
 ISO8601DateFormatter iso8601(const Date &d) { return ISO8601DateFormatter(d); }
 
 TEST(StrTest, pad) {
+  EXPECT_EQ("    cafe", (BasicFormatter() << pad(hex(0xcafe), 8)).str());
+  EXPECT_EQ("    babe", (BasicFormatter() << pad(hex(0xbabeu), 8)).str());
+  EXPECT_EQ("    dead", (BasicFormatter() << pad(hex(0xdeadl), 8)).str());
+  EXPECT_EQ("    beef", (BasicFormatter() << pad(hex(0xbeeful), 8)).str());
+
+  EXPECT_EQ("     11", (BasicFormatter() << pad(11, 7)).str());
+  EXPECT_EQ("     22", (BasicFormatter() << pad(22u, 7)).str());
+  EXPECT_EQ("     33", (BasicFormatter() << pad(33l, 7)).str());
+  EXPECT_EQ("     44", (BasicFormatter() << pad(44lu, 7)).str());
+
   BasicFormatter f;
-  f << pad(hex(0xbeef), 8);
-  EXPECT_EQ("    beef", f.str());
   f.Clear();
   f << pad(42, 5, '0');
   EXPECT_EQ("00042", f.str());