message: [terminal] GridSize: adds fmtlib formatter
diff: @@ -497,4 +497,19 @@ struct formatter<terminal::PageSize>
  return format_to(ctx.out(), "{}x{}", value.columns, value.lines);
  }
  };
  +
  +template <>
  +struct formatter<terminal::GridSize>
  +{
  + template <typename ParseContext>
  + constexpr auto parse(ParseContext& ctx)
  + {
  + return ctx.begin();
  + }
  + template <typename FormatContext>
  + auto format(terminal::GridSize value, FormatContext& ctx)
  + {
  + return format_to(ctx.out(), "{}x{}", value.columns, value.lines);
  + }
  +};
  } // namespace fmt
  