A unary expression preceded by a ++ operator is a prefix increment expression.
The result of the unary expression must be a variable of a type that is convertible
(5.1.8) to a numeric type, or a compile-time error occurs. The type of the prefix
increment expression is the type of the variable. The result of the prefix increment
expression is not a variable, but a value.
其中：The result of the unary expression must be a variable of a type that is convertible
(5.1.8) to a numeric type, or a compile-time error occurs. 这段话说的是个什么意思？中文译本也有，但是翻译的惨不忍睹。
The result of the unary expression must be a variable of a type that is convertible
(5.1.8) to a numeric type, or a compile-time error occurs. The type of the prefix
increment expression is the type of the variable. The result of the prefix increment
expression is not a variable, but a value.
其中：The result of the unary expression must be a variable of a type that is convertible
(5.1.8) to a numeric type, or a compile-time error occurs. 这段话说的是个什么意思？中文译本也有，但是翻译的惨不忍睹。
