fix formatting with empty compiled format string (#2042)

fmtlib · Dec 3, 2020 · c609ebf · c609ebf
1 parent f43416e
commit c609ebf
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Showing 4 changed files with 16 additions and 2 deletions.
diff --git a/include/fmt/compile.h b/include/fmt/compile.h
@@ -643,7 +643,7 @@ FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
 #ifdef __cpp_if_constexpr
   if constexpr (std::is_same<typename S::char_type, char>::value) {
     constexpr basic_string_view<typename S::char_type> str = S();
-    if (str.size() == 2 && str[0] == '{' && str[1] == '}')
+    if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}')
       return fmt::to_string(detail::first(args...));
   }
 #endif

diff --git a/include/fmt/format.h b/include/fmt/format.h
@@ -3538,7 +3538,7 @@ struct formatter<T, Char,
   struct formatter<Type, Char> : formatter<Base, Char> {                      \
     template <typename FormatContext>                                         \
     auto format(Type const& val, FormatContext& ctx) -> decltype(ctx.out()) { \
-      return formatter<Base, Char>::format(val, ctx);                         \
+      return formatter<Base, Char>::format(static_cast<Base>(val), ctx);      \
     }                                                                         \
   }
 
@@ -3552,6 +3552,9 @@ FMT_FORMAT_AS(Char*, const Char*);
 FMT_FORMAT_AS(std::basic_string<Char>, basic_string_view<Char>);
 FMT_FORMAT_AS(std::nullptr_t, const void*);
 FMT_FORMAT_AS(detail::std_string_view<Char>, basic_string_view<Char>);
+#if __cplusplus >= 201703L
+FMT_FORMAT_AS(std::byte, unsigned);
+#endif
 
 template <typename Char>
 struct formatter<void*, Char> : formatter<const void*, Char> {

diff --git a/test/compile-test.cc b/test/compile-test.cc
@@ -173,6 +173,10 @@ TEST(CompileTest, TextAndArg) {
   EXPECT_EQ(">>>42<<<", fmt::format(FMT_COMPILE(">>>{}<<<"), 42));
   EXPECT_EQ("42!", fmt::format(FMT_COMPILE("{}!"), 42));
 }
+
+TEST(CompileTest, Empty) {
+  EXPECT_EQ("", fmt::format(FMT_COMPILE("")));
+}
 #endif
 
 #if __cplusplus >= 202002L

diff --git a/test/format-test.cc b/test/format-test.cc
@@ -1762,6 +1762,13 @@ TEST(FormatTest, JoinArg) {
 #endif
 }
 
+#if __cplusplus >= 201703L
+TEST(FormatTest, JoinBytes) {
+  std::vector<std::byte> v = {std::byte(1), std::byte(2), std::byte(3)};
+  EXPECT_EQ("1, 2, 3", fmt::format("{}", fmt::join(v, ", ")));
+}
+#endif
+
 template <typename T> std::string str(const T& value) {
   return fmt::format("{}", value);
 }