Parameterize v*printf on string type (#920)

include/fmt/core.h

@@ -1398,7 +1398,7 @@ typename std::enable_if<
     const S &format_str,
     basic_format_args<typename buffer_context<FMT_CHAR(S)>::type> args) {
   internal::container_buffer<Container> buf(internal::get_container(out));
-  vformat_to(buf, to_string_view(format_str), args);
+  internal::vformat_to(buf, to_string_view(format_str), args);
   return out;
 }
 

include/fmt/format-inl.h

@@ -943,14 +943,14 @@ FMT_FUNC void report_windows_error(
 
 FMT_FUNC void vprint(std::FILE *f, string_view format_str, format_args args) {
   memory_buffer buffer;
-  vformat_to(buffer, format_str,
+  internal::vformat_to(buffer, format_str,
                        basic_format_args<buffer_context<char>::type>(args));
   std::fwrite(buffer.data(), 1, buffer.size(), f);
 }
 
 FMT_FUNC void vprint(std::FILE *f, wstring_view format_str, wformat_args args) {
   wmemory_buffer buffer;
-  vformat_to(buffer, format_str, args);
+  internal::vformat_to(buffer, format_str, args);
   std::fwrite(buffer.data(), sizeof(wchar_t), buffer.size(), f);
 }
 

include/fmt/format.h

@@ -3378,7 +3378,7 @@ template <typename S, typename Char = FMT_CHAR(S)>
 inline typename buffer_context<Char>::type::iterator vformat_to(
     internal::basic_buffer<Char> &buf, const S &format_str,
     basic_format_args<typename buffer_context<Char>::type> args) {
-  return vformat_to(buf, to_string_view(format_str), args);
+  return internal::vformat_to(buf, to_string_view(format_str), args);
 }
 
 template <
@@ -3391,7 +3391,7 @@ inline typename buffer_context<Char>::type::iterator format_to(
   internal::check_format_string<Args...>(format_str);
   typedef typename buffer_context<Char>::type context;
   format_arg_store<context, Args...> as{args...};
-  return vformat_to(buf, to_string_view(format_str),
+  return internal::vformat_to(buf, to_string_view(format_str),
                               basic_format_args<context>(as));
 }
 
@@ -3495,7 +3495,7 @@ inline std::basic_string<Char> internal::vformat(
     basic_string_view<Char> format_str,
     basic_format_args<typename buffer_context<Char>::type> args) {
   basic_memory_buffer<Char> buffer;
-  vformat_to(buffer, format_str, args);
+  internal::vformat_to(buffer, format_str, args);
   return fmt::to_string(buffer);
 }
 

include/fmt/ostream.h

@@ -129,7 +129,7 @@ inline void vprint(std::basic_ostream<Char> &os,
                    basic_string_view<Char> format_str,
                    basic_format_args<typename buffer_context<Char>::type> args) {
   basic_memory_buffer<Char> buffer;
-  vformat_to(buffer, format_str, args);
+  internal::vformat_to(buffer, format_str, args);
   internal::write(os, buffer);
 }
 /**

include/fmt/printf.h

@@ -580,13 +580,13 @@ struct printf_context {
 typedef basic_format_args<printf_context<internal::buffer>::type> printf_args;
 typedef basic_format_args<printf_context<internal::wbuffer>::type> wprintf_args;
 
-template <typename Char>
+template <typename S, typename Char = FMT_CHAR(S)>
 inline std::basic_string<Char>
-vsprintf(basic_string_view<Char> format,
+vsprintf(const S &format,
          basic_format_args<typename printf_context<
            internal::basic_buffer<Char>>::type> args) {
   basic_memory_buffer<Char> buffer;
-  printf(buffer, format, args);
+  printf(buffer, to_string_view(format), args);
   return to_string(buffer);
 }
 
@@ -601,21 +601,21 @@ vsprintf(basic_string_view<Char> format,
 */
 template <typename S, typename... Args>
 inline FMT_ENABLE_IF_STRING(S, std::basic_string<FMT_CHAR(S)>)
-    sprintf(const S &format_str, const Args & ... args) {
-  internal::check_format_string<Args...>(format_str);
+    sprintf(const S &format, const Args & ... args) {
+  internal::check_format_string<Args...>(format);
   typedef internal::basic_buffer<FMT_CHAR(S)> buffer;
   typedef typename printf_context<buffer>::type context;
   format_arg_store<context, Args...> as{ args... };
-  return vsprintf(to_string_view(format_str),
+  return vsprintf(to_string_view(format),
                   basic_format_args<context>(as));
 }
 
-template <typename Char>
-inline int vfprintf(std::FILE *f, basic_string_view<Char> format,
+template <typename S, typename Char = FMT_CHAR(S)>
+inline int vfprintf(std::FILE *f, const S &format,
                     basic_format_args<typename printf_context<
                       internal::basic_buffer<Char>>::type> args) {
   basic_memory_buffer<Char> buffer;
-  printf(buffer, format, args);
+  printf(buffer, to_string_view(format), args);
   std::size_t size = buffer.size();
   return std::fwrite(
     buffer.data(), sizeof(Char), size, f) < size ? -1 : static_cast<int>(size);
@@ -632,20 +632,20 @@ inline int vfprintf(std::FILE *f, basic_string_view<Char> format,
  */
 template <typename S, typename... Args>
 inline FMT_ENABLE_IF_STRING(S, int)
-    fprintf(std::FILE *f, const S &format_str, const Args & ... args) {
-  internal::check_format_string<Args...>(format_str);
+    fprintf(std::FILE *f, const S &format, const Args & ... args) {
+  internal::check_format_string<Args...>(format);
   typedef internal::basic_buffer<FMT_CHAR(S)> buffer;
   typedef typename printf_context<buffer>::type context;
   format_arg_store<context, Args...> as{ args... };
-  return vfprintf(f, to_string_view(format_str),
+  return vfprintf(f, to_string_view(format),
                   basic_format_args<context>(as));
 }
 
-template <typename Char>
-inline int vprintf(basic_string_view<Char> format,
+template <typename S, typename Char = FMT_CHAR(S)>
+inline int vprintf(const S &format,
                    basic_format_args<typename printf_context<
                     internal::basic_buffer<Char>>::type> args) {
-  return vfprintf(stdout, format, args);
+  return vfprintf(stdout, to_string_view(format), args);
 }
 
 /**
@@ -668,13 +668,13 @@ inline FMT_ENABLE_IF_STRING(S, int)
                  basic_format_args<context>(as));
 }
 
-template <typename Char>
+template <typename S, typename Char = FMT_CHAR(S)>
 inline int vfprintf(std::basic_ostream<Char> &os,
-                    basic_string_view<Char> format_str,
+                    const S &format,
                     basic_format_args<typename printf_context<
                       internal::basic_buffer<Char>>::type> args) {
   basic_memory_buffer<Char> buffer;
-  printf(buffer, format_str, args);
+  printf(buffer, to_string_view(format), args);
   internal::write(os, buffer);
   return static_cast<int>(buffer.size());
 }

test/printf-test.cc

@@ -499,3 +499,13 @@ TEST(PrintfTest, OStream) {
   EXPECT_EQ("Don't panic!", os.str());
   EXPECT_EQ(12, ret);
 }
+
+TEST(PrintfTest, VPrintf) {
+  typedef fmt::printf_context<fmt::internal::buffer>::type context;
+  fmt::format_arg_store<context, int> as{42};
+  fmt::basic_format_args<context> args(as);
+  EXPECT_EQ(fmt::vsprintf("%d", args), "42");
+  EXPECT_WRITE(stdout, fmt::vprintf("%d", args), "42");
+  EXPECT_WRITE(stdout, fmt::vfprintf(stdout, "%d", args), "42");
+  EXPECT_WRITE(stdout, fmt::vfprintf(std::cout, "%d", args), "42");
+}