Is there a function in Rust regex to calculate the size of the compiled regex？

[yangwentong]

I want to calculate the size of the compiled regex.
ProgramSize is provided in RE2 to calculate the size.

[BurntSushi]

Nope.

[yangwentong]

I would like to know why this function is not implemented?

[BurntSushi]

Because nobody has done it. Nobody has asked for it. And nobody has given a good reason for why it should exist.

[yangwentong]

thank you