Class custom_container

test/base-test.cc:865–875

}

struct custom_container {
  char data;

  using value_type = char;

  auto size() const -> size_t { return 0; }
  void resize(size_t) {}

  void push_back(char) {}
  auto operator[](size_t) -> char& { return data; }
};

FMT_BEGIN_NAMESPACE
template <> struct is_contiguous<custom_container> : std::true_type {};