Fix an inconsistentcy between to_string and format

fmtlib · Oct 28, 2023 · 19276d7 · 19276d7
1 parent 2a2c6e6
commit 19276d7
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/include/fmt/format.h b/include/fmt/format.h
@@ -3751,8 +3751,11 @@ template <typename Char, typename OutputIt, typename T,
 FMT_CONSTEXPR auto write(OutputIt out, const T& value)
     -> enable_if_t<mapped_type_constant<T, Context>::value == type::custom_type,
                    OutputIt> {
+  auto formatter = typename Context::template formatter_type<T>();
+  auto parse_ctx = typename Context::parse_context_type({});
+  formatter.parse(parse_ctx);
   auto ctx = Context(out, {}, {});
-  return typename Context::template formatter_type<T>().format(value, ctx);
+  return formatter.format(value, ctx);
 }
 
 // An argument visitor that formats the argument and writes it via the output

diff --git a/test/ranges-test.cc b/test/ranges-test.cc
@@ -59,13 +59,18 @@ TEST(ranges_test, format_vector) {
   EXPECT_EQ(fmt::format("{:n:n:}", vvc), "a, b, c, a, b, c");
 }
 
-TEST(ranges_test, format_vector2) {
+TEST(ranges_test, format_nested_vector) {
   auto v = std::vector<std::vector<int>>{{1, 2}, {3, 5}, {7, 11}};
   EXPECT_EQ(fmt::format("{}", v), "[[1, 2], [3, 5], [7, 11]]");
   EXPECT_EQ(fmt::format("{:::#x}", v), "[[0x1, 0x2], [0x3, 0x5], [0x7, 0xb]]");
   EXPECT_EQ(fmt::format("{:n:n:#x}", v), "0x1, 0x2, 0x3, 0x5, 0x7, 0xb");
 }
 
+TEST(ranges_test, to_string_vector) {
+  auto v = std::vector<std::string>{"a", "b", "c"};
+  EXPECT_EQ(fmt::to_string(v), "[\"a\", \"b\", \"c\"]");
+}
+
 TEST(ranges_test, format_map) {
   auto m = std::map<std::string, int>{{"one", 1}, {"two", 2}};
   EXPECT_EQ(fmt::format("{}", m), "{\"one\": 1, \"two\": 2}");