Expressions must have integral type and can include only integer constants, character constants, and the defined operator.

表达式必须有整数类型并且只能包括整数常量，字符常量，以及定义了的运算符。

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The New York Independent System Operator has defined short-term energy storage devices like flywheels and batteries as frequency regulators, allowing them to participate in regulated markets.

FORBES: Energy Storage Critical to Solar Industry

He in many ways defined what it meant to be a Russian oligarch, becoming a power broker, political operator and businessman all at once.

WSJ: Boris Berezovsky, Exiled Russian Tycoon, Dies