Method test_buffer

test/base-test.cc:413–415

    struct test_buffer final : fmt::detail::buffer<char> {
      char data[10];
      test_buffer()
          : fmt::detail::buffer<char>([](buffer<char>&, size_t) {}, data, 0,
                                      10) {}
    } buffer;
    auto parse_ctx = fmt::format_parse_context("");
    auto ctx = fmt::format_context(fmt::appender(buffer), fmt::format_args());