Deprecate u8string_view

include/fmt/core.h

@@ -1535,7 +1535,8 @@ inline void print(std::FILE* f, const S& format_str, Args&&... args) {
 
 /**
   \rst
-  Prints formatted data to ``stdout``.
+  Formats ``args`` according to specifications in ``format_str`` and writes the
+  output to ``stdout``.
 
   **Example**::
 

include/fmt/format.h

@@ -559,8 +559,7 @@ class buffer_range : public internal::output_range<
       : internal::output_range<iterator, T>(std::back_inserter(buf)) {}
 };
 
-// A UTF-8 string view.
-class u8string_view : public basic_string_view<char8_t> {
+class FMT_DEPRECATED u8string_view : public basic_string_view<char8_t> {
  public:
   u8string_view(const char* s)
       : basic_string_view<char8_t>(reinterpret_cast<const char8_t*>(s)) {}
@@ -571,8 +570,8 @@ class u8string_view : public basic_string_view<char8_t> {
 
 #if FMT_USE_USER_DEFINED_LITERALS
 inline namespace literals {
-inline u8string_view operator"" _u(const char* s, std::size_t n) {
-  return {s, n};
+inline basic_string_view<char8_t> operator"" _u(const char* s, std::size_t n) {
+  return {reinterpret_cast<const char8_t*>(s), n};
 }
 }  // namespace literals
 #endif

test/format-impl-test.cc

@@ -427,7 +427,11 @@ TEST(FormatTest, FormatErrorCode) {
 }
 
 TEST(FormatTest, CountCodePoints) {
-  EXPECT_EQ(4, fmt::internal::count_code_points(fmt::u8string_view("ёжик")));
+#ifndef __cpp_char8_t
+  using fmt::char8_t;
+#endif
+  EXPECT_EQ(4, fmt::internal::count_code_points(
+    fmt::basic_string_view<char8_t>(reinterpret_cast<const char8_t*>("ёжик"))));
 }
 
 // Tests fmt::internal::count_digits for integer type Int.

test/format-test.cc

@@ -2467,27 +2467,10 @@ TEST(FormatTest, FmtStringInTemplate) {
 using fmt::char8_t;
 #endif
 
-TEST(FormatTest, ConstructU8StringViewFromCString) {
-  fmt::u8string_view s("ab");
-  EXPECT_EQ(s.size(), 2u);
-  const char8_t* data = s.data();
-  EXPECT_EQ(data[0], 'a');
-  EXPECT_EQ(data[1], 'b');
-}
-
-TEST(FormatTest, ConstructU8StringViewFromDataAndSize) {
-  fmt::u8string_view s("foobar", 3);
-  EXPECT_EQ(s.size(), 3u);
-  const char8_t* data = s.data();
-  EXPECT_EQ(data[0], 'f');
-  EXPECT_EQ(data[1], 'o');
-  EXPECT_EQ(data[2], 'o');
-}
-
 #if FMT_USE_USER_DEFINED_LITERALS
 TEST(FormatTest, U8StringViewLiteral) {
   using namespace fmt::literals;
-  fmt::u8string_view s = "ab"_u;
+  fmt::basic_string_view<char8_t> s = "ab"_u;
   EXPECT_EQ(s.size(), 2u);
   const char8_t* data = s.data();
   EXPECT_EQ(data[0], 'a');
@@ -2496,10 +2479,6 @@ TEST(FormatTest, U8StringViewLiteral) {
 }
 #endif
 
-TEST(FormatTest, FormatU8String) {
-  EXPECT_EQ(format(fmt::u8string_view("{}"), 42), fmt::u8string_view("42"));
-}
-
 TEST(FormatTest, EmphasisNonHeaderOnly) {
   // Ensure this compiles even if FMT_HEADER_ONLY is not defined.
   EXPECT_EQ(fmt::format(fmt::emphasis::bold, "bold error"),