Add color format_to overloads

* Fix variable size basic_memory_buffer colorization * Fix an unused arguments warning on GCC that blocks the CI otherwise * Ref #1842 * Ref #1593
fmtlib · Sep 4, 2020 · 9d44ba4 · 9d44ba4
1 parent f8e00a0
commit 9d44ba4
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Showing 3 changed files with 75 additions and 4 deletions.
diff --git a/include/fmt/color.h b/include/fmt/color.h
@@ -463,16 +463,16 @@ template <> inline void reset_color<wchar_t>(FILE* stream) FMT_NOEXCEPT {
 }
 
 template <typename Char>
-inline void reset_color(basic_memory_buffer<Char>& buffer) FMT_NOEXCEPT {
+inline void reset_color(buffer<Char>& buffer) FMT_NOEXCEPT {
   const char* begin = data::reset_color;
   const char* end = begin + sizeof(data::reset_color) - 1;
   buffer.append(begin, end);
 }
 
 template <typename Char>
-void vformat_to(basic_memory_buffer<Char>& buf, const text_style& ts,
+void vformat_to(buffer<Char>& buf, const text_style& ts,
                 basic_string_view<Char> format_str,
-                basic_format_args<buffer_context<Char>> args) {
+                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   bool has_style = false;
   if (ts.has_emphasis()) {
     has_style = true;
@@ -563,6 +563,49 @@ inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
                  fmt::make_args_checked<Args...>(format_str, args...));
 }
 
+/** Formats a string with the given text_style and writes the output to ``out``.
+ */
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt>::value)>
+OutputIt vformat_to(
+    OutputIt out, const text_style& ts, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
+  detail::vformat_to(buf, ts, to_string_view(format_str), args);
+  return detail::get_iterator(buf);
+}
+
+/**
+ \rst
+ Formats arguments with the given text_style, writes the result to the output
+ iterator ``out`` and returns the iterator past the end of the output range.
+
+ **Example**::
+
+   std::vector<char> out;
+   fmt::format_to(std::back_inserter(out),
+                  fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+   \endrst
+ */
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt>::value&&
+                            detail::is_string<S>::value)>
+inline OutputIt format_to(OutputIt out, const text_style& ts,
+                          const S& format_str, Args&&... args) {
+  return vformat_to(out, ts, to_string_view(format_str),
+                    fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+template <typename S, typename... Args, size_t SIZE = inline_buffer_size,
+          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+inline typename buffer_context<Char>::iterator format_to(
+    basic_memory_buffer<Char, SIZE>& buf, const text_style& ts,
+    const S& format_str, Args&&... args) {
+  detail::vformat_to(buf, ts, to_string_view(format_str),
+                     fmt::make_args_checked<Args...>(format_str, args...));
+  return detail::buffer_appender<Char>(buf);
+}
+
 FMT_END_NAMESPACE
 
 #endif  // FMT_COLOR_H_
diff --git a/test/color-test.cc b/test/color-test.cc
@@ -7,6 +7,10 @@
 
 #include "fmt/color.h"
 
+#include <iterator>
+#include <string>
+#include <utility>
+
 #include "gtest-extra.h"
 
 TEST(ColorsTest, ColorsPrint) {
@@ -84,3 +88,21 @@ TEST(ColorsTest, Format) {
   EXPECT_EQ(fmt::format(fg(fmt::terminal_color::red), "{}", "foo"),
             "\x1b[31mfoo\x1b[0m");
 }
+
+TEST(ColorsTest, FormatToOutAcceptsTextStyle) {
+  fmt::text_style const ts = fg(fmt::rgb(255, 20, 30));
+  std::string out;
+  fmt::format_to(std::back_inserter(out), ts, "rgb(255,20,30){}{}{}", 1, 2, 3);
+
+  EXPECT_EQ(fmt::to_string(out),
+            "\x1b[38;2;255;020;030mrgb(255,20,30)123\x1b[0m");
+}
+
+TEST(ColorsTest, FormatToAcceptsTextStyle) {
+  fmt::text_style const ts = fg(fmt::rgb(255, 20, 30));
+  fmt::basic_memory_buffer<char> out;
+  fmt::format_to(out, ts, "rgb(255,20,30){}{}{}", 1, 2, 3);
+
+  EXPECT_EQ(fmt::to_string(out),
+            "\x1b[38;2;255;020;030mrgb(255,20,30)123\x1b[0m");
+}
diff --git a/test/gtest-extra.h b/test/gtest-extra.h
@@ -145,7 +145,13 @@ std::string read(fmt::file& f, size_t count);
               read(file, fmt::string_view(expected_content).size()))
 
 #else
-#  define EXPECT_WRITE(file, statement, expected_output) SUCCEED()
+#  define EXPECT_WRITE(file, statement, expected_output) \
+    do {                                                 \
+      (void)(file);                                      \
+      (void)(statement);                                 \
+      (void)(expected_output);                           \
+      SUCCEED();                                         \
+    } while (false)
 #endif  // FMT_USE_FCNTL
 
 template <typename Mock> struct ScopedMock : testing::StrictMock<Mock> {