Class printf_width_handler

include/fmt/printf.h:196–220

Checks if an argument is a valid printf width specifier and sets left alignment if it is negative.

// Checks if an argument is a valid printf width specifier and sets
// left alignment if it is negative.
class printf_width_handler {
 private:
  format_specs& specs_;

 public:
  inline explicit printf_width_handler(format_specs& specs) : specs_(specs) {}

  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
  auto operator()(T value) -> unsigned {
    auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
    if (detail::is_negative(value)) {
      specs_.set_align(align::left);
      width = 0 - width;
    }
    unsigned int_max = to_unsigned(max_value<int>());
    if (width > int_max) report_error("number is too big");
    return static_cast<unsigned>(width);
  }

  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
  auto operator()(T) -> unsigned {
    report_error("width is not integer");
    return 0;
  }
};

// Workaround for a bug with the XL compiler when initializing
// printf_arg_formatter's base class.