identity sign的用法和樣例：
例句
用作名詞 (n.)
- A member initializer that specifes an object initializer after the equals sign is an initialization of an embedded object.
成員構造者特指某個等號後面的對象構造者，是內嵌對象的初始化。 - Add the value on the right side of the equal sign to the current value that is contained in the variable on the left side of the equal sign.
將等號右側的值添加到等號左側的變數中包含的當前值。
