Spec template argument defaulted to FormatSpec

doc/api.rst

@@ -120,19 +120,17 @@ custom argument formatter class::
   // A custom argument formatter that formats negative integers as unsigned
   // with the ``x`` format specifier.
   class CustomArgFormatter :
-    public fmt::BasicArgFormatter<CustomArgFormatter, char, fmt::FormatSpec> {
+    public fmt::BasicArgFormatter<CustomArgFormatter, char> {
     public:
     CustomArgFormatter(fmt::BasicFormatter<char, CustomArgFormatter> &f,
                        fmt::FormatSpec &s, const char *fmt)
-      : fmt::BasicArgFormatter<CustomArgFormatter, char,
+      : fmt::BasicArgFormatter<CustomArgFormatter, char>(f, s, fmt) {}
-                               fmt::FormatSpec>(f, s, fmt) {}
 
     void visit_int(int value) {
       if (spec().type() == 'x')
         visit_uint(value); // convert to unsigned and format
       else
-        fmt::BasicArgFormatter<CustomArgFormatter, char,
+        fmt::BasicArgFormatter<CustomArgFormatter, char>::visit_int(value);
-                               fmt::FormatSpec>::visit_int(value);
     }
   };
 

fmt/format.h

@@ -431,7 +431,7 @@ typedef BasicWriter<wchar_t> WWriter;
 template <typename Char>
 class ArgFormatter;
 
-template <typename Impl, typename Char, typename Spec>
+template <typename Impl, typename Char, typename Spec = fmt::FormatSpec>
 class BasicPrintfArgFormatter;
 
 template <typename CharType,
@@ -1925,7 +1925,7 @@ class ArgMap {
   }
 };
 
-template <typename Impl, typename Char, typename Spec>
+template <typename Impl, typename Char, typename Spec = fmt::FormatSpec>
 class ArgFormatterBase : public ArgVisitor<Impl, void> {
  private:
   BasicWriter<Char> &writer_;
@@ -2091,7 +2091,7 @@ class FormatterBase {
   will be called.
   \endrst
  */
-template <typename Impl, typename Char, typename Spec>
+template <typename Impl, typename Char, typename Spec = fmt::FormatSpec>
 class BasicArgFormatter : public internal::ArgFormatterBase<Impl, Char, Spec> {
  private:
   BasicFormatter<Char, Impl> &formatter_;

test/custom-formatter-test.cc

@@ -15,29 +15,25 @@ using fmt::BasicPrintfArgFormatter;
 // A custom argument formatter that doesn't print `-` for floating-point values
 // rounded to 0.
 class CustomArgFormatter :
-    public fmt::BasicArgFormatter<CustomArgFormatter, char, fmt::FormatSpec> {
+    public fmt::BasicArgFormatter<CustomArgFormatter, char> {
  public:
   CustomArgFormatter(fmt::BasicFormatter<char, CustomArgFormatter> &f,
                      fmt::FormatSpec &s, const char *fmt)
-  : fmt::BasicArgFormatter<CustomArgFormatter, char,
+  : fmt::BasicArgFormatter<CustomArgFormatter, char>(f, s, fmt) {}
-                           fmt::FormatSpec>(f, s, fmt) {}
 
   void visit_double(double value) {
     if (round(value * pow(10, spec().precision())) == 0)
       value = 0;
-    fmt::BasicArgFormatter<CustomArgFormatter, char,
+    fmt::BasicArgFormatter<CustomArgFormatter, char>::visit_double(value);
-                           fmt::FormatSpec>::visit_double(value);
   }
 };
 
 // A custom argument formatter that doesn't print `-` for floating-point values
 // rounded to 0.
 class CustomPrintfArgFormatter :
-    public BasicPrintfArgFormatter<CustomPrintfArgFormatter, char,
+    public BasicPrintfArgFormatter<CustomPrintfArgFormatter, char> {
-                                   fmt::FormatSpec> {
  public:
-  typedef BasicPrintfArgFormatter<CustomPrintfArgFormatter, char,
+  typedef BasicPrintfArgFormatter<CustomPrintfArgFormatter, char> Base;
-                                  fmt::FormatSpec> Base;
 
   CustomPrintfArgFormatter(fmt::BasicWriter<char> &w, fmt::FormatSpec &spec)
   : Base(w, spec) {}

test/format-test.cc

@@ -1630,16 +1630,13 @@ TEST(FormatTest, Enum) {
 }
 
 class MockArgFormatter :
-    public fmt::internal::ArgFormatterBase<MockArgFormatter, char,
+    public fmt::internal::ArgFormatterBase<MockArgFormatter, char> {
-                                           fmt::FormatSpec> {
  public:
-  typedef fmt::internal::ArgFormatterBase<MockArgFormatter, char,
+  typedef fmt::internal::ArgFormatterBase<MockArgFormatter, char> Base;
-                                          fmt::FormatSpec> Base;
 
   MockArgFormatter(fmt::BasicFormatter<char, MockArgFormatter> &f,
                    fmt::FormatSpec &s, const char *)
-    : fmt::internal::ArgFormatterBase<MockArgFormatter,
+    : fmt::internal::ArgFormatterBase<MockArgFormatter, char>(f.writer(), s) {
-                                      char, fmt::FormatSpec>(f.writer(), s) {
     EXPECT_CALL(*this, visit_int(42));
   }
 
@@ -1663,4 +1660,3 @@ void convert(int);
 TEST(FormatTest, ConvertCollision) {
   fmt::format("{}", 42);
 }
-

test/ostream-test.cc

@@ -58,12 +58,10 @@ TEST(OStreamTest, Enum) {
   EXPECT_EQ("0", fmt::format("{}", A));
 }
 
-struct TestArgFormatter :
+struct TestArgFormatter : fmt::BasicArgFormatter<TestArgFormatter, char> {
-    fmt::BasicArgFormatter<TestArgFormatter, char, fmt::FormatSpec> {
   TestArgFormatter(fmt::BasicFormatter<char, TestArgFormatter> &f,
                    fmt::FormatSpec &s, const char *fmt)
-    : fmt::BasicArgFormatter<TestArgFormatter, char,
+    : fmt::BasicArgFormatter<TestArgFormatter, char>(f, s, fmt) {}
-                             fmt::FormatSpec>(f, s, fmt) {}
 };
 
 TEST(OStreamTest, CustomArg) {