Move writer to PrintfFormatter object for consistency with BasicFormatter

fmt/format.cc

@@ -521,8 +521,7 @@ template void internal::FixedBuffer<char>::grow(std::size_t);
 
 template void internal::ArgMap<char>::init(const ArgList &args);
 
-template void PrintfFormatter<char>::format(
-  BasicWriter<char> &writer, CStringRef format);
+template void PrintfFormatter<char>::format(CStringRef format);
 
 template int internal::CharTraits<char>::format_float(
     char *buffer, std::size_t size, const char *format,
@@ -538,8 +537,7 @@ template void internal::FixedBuffer<wchar_t>::grow(std::size_t);
 
 template void internal::ArgMap<wchar_t>::init(const ArgList &args);
 
-template void PrintfFormatter<wchar_t>::format(
-    BasicWriter<wchar_t> &writer, WCStringRef format);
+template void PrintfFormatter<wchar_t>::format(WCStringRef format);
 
 template int internal::CharTraits<wchar_t>::format_float(
     wchar_t *buffer, std::size_t size, const wchar_t *format,

fmt/printf.h

@@ -255,6 +255,8 @@ template <typename Char,
           typename ArgFormatter = internal::PrintfArgFormatter<Char> >
 class PrintfFormatter : private internal::FormatterBase {
  private:
+  BasicWriter<Char> &writer_;
+
   void parse_flags(FormatSpec &spec, const Char *&s);
 
   // Returns the argument with specified index or, if arg_index is equal
@@ -269,15 +271,15 @@ class PrintfFormatter : private internal::FormatterBase {
  public:
   /**
    \rst
-   Constructs a ``PrintfFormatter`` object. References to the arguments
-   are stored in the formatter object so make sure they have appropriate
-   lifetimes.
+   Constructs a ``PrintfFormatter`` object. References to the arguments and
+   the writer are stored in the formatter object so make sure they have
+   appropriate lifetimes.
    \endrst
    */
-  explicit PrintfFormatter(const ArgList &args) : FormatterBase(args) {}
+  explicit PrintfFormatter(const ArgList &args, BasicWriter<Char> &w)
+    : FormatterBase(args), writer_(w) {}
 
-  FMT_API void format(BasicWriter<Char> &writer,
-                      BasicCStringRef<Char> format_str);
+  FMT_API void format(BasicCStringRef<Char> format_str);
 };
 
 template <typename Char, typename AF>
@@ -353,19 +355,18 @@ unsigned PrintfFormatter<Char, AF>::parse_header(
 }
 
 template <typename Char, typename AF>
-void PrintfFormatter<Char, AF>::format(
-    BasicWriter<Char> &writer, BasicCStringRef<Char> format_str) {
+void PrintfFormatter<Char, AF>::format(BasicCStringRef<Char> format_str) {
   const Char *start = format_str.c_str();
   const Char *s = start;
   while (*s) {
     Char c = *s++;
     if (c != '%') continue;
     if (*s == c) {
-      write(writer, start, s);
+      write(writer_, start, s);
       start = ++s;
       continue;
     }
-    write(writer, start, s - 1);
+    write(writer_, start, s - 1);
 
     FormatSpec spec;
     spec.align_ = ALIGN_RIGHT;
@@ -448,14 +449,14 @@ void PrintfFormatter<Char, AF>::format(
     start = s;
 
     // Format argument.
-    AF(writer, spec).visit(arg);
+    AF(writer_, spec).visit(arg);
   }
-  write(writer, start, s);
+  write(writer_, start, s);
 }
 
 template <typename Char>
 void printf(BasicWriter<Char> &w, BasicCStringRef<Char> format, ArgList args) {
-  PrintfFormatter<Char>(args).format(w, format);
+  PrintfFormatter<Char>(args, w).format(format);
 }
 
 /**

test/custom-formatter-test.cc

@@ -51,10 +51,10 @@ std::string custom_format(const char *format_str, fmt::ArgList args) {
 }
 FMT_VARIADIC(std::string, custom_format, const char *)
 
-std::string custom_sprintf(const char* fstr, fmt::ArgList args){
+std::string custom_sprintf(const char* format_str, fmt::ArgList args){
   fmt::MemoryWriter writer;
-  fmt::PrintfFormatter<char, CustomPAF> pfer( args);
-  pfer.format(writer, fstr);
+  fmt::PrintfFormatter<char, CustomPAF> formatter(args, writer);
+  formatter.format(format_str);
   return writer.str();
 }
 FMT_VARIADIC(std::string, custom_sprintf, const char*);