string-formatting - 如何在 Rust 的格式字符串中转义大括号

Question

我想写这个

write!(f, "{ hash:{}, subject: {} }", self.hash, self.subject)

但是由于花括号对格式化有特殊意义，所以很明显我不能在不转义的情况下那样放置外部花括号。所以我想逃避他们。

write!(f, "\{ hash:{}, subject: {} \}", self.hash, self.subject)

Rust 也不喜欢这样。然后我读到这个:

The literal characters {, }, or # may be included in a string by preceding them with the \ character. Since \ is already an escape character in Rust strings, a string literal using this escape will look like "\{".

所以我试过了

write!(f, "\\{ hash:{}, subject: {} \\}", self.hash, self.subject)

但这也行不通。 :-(

Answer 1

您可能正在阅读一些过时的文档(例如 Rust 0.9)

从 Rust 1.0 开始，the way to escape { and } is with another { or }

write!(f, "{{ hash:{}, subject: {} }}", self.hash, self.subject)

The literal characters { and } may be included in a string by preceding them with the same character. For example, the { character is escaped with {{ and the } character is escaped with }}.