Both with value and without value case

[tobisako]

Hi, I'll try implement this case. but, I have no idea how to this implement.
command line
a. ./cmd sub -t true -> true
b. ./cmd sub -t false -> false
c. ./cmd sub -t -> true
d. ./cmd sub -> false

-t both with value and without value case.

sample code (not work)

https://github.com/tobisako/rust-memo/blob/master/crates/clap/clap3/src/main.rs

I can implement this case:
a. ./cmd sub -t true -> true
b. ./cmd sub -t false -> false
c. ./cmd sub -t -> error: Found (clap)
d. ./cmd sub -> error: Found (clap)

but, not enough to me.

I searched clap-examples, but I haven't idea.
Im looking for how to implement this. or this case is not covered? please help.
thank you.

Version

Rust: 1.45.0

Clap: 2.33.3

[pksunkara]

default_value and default_missing_value API should help you. Please search the clap v3 docs for them.

[tobisako]

@pksunkara thank you for your guide.

I'm looking for clap v3 docs,
https://docs.rs/clap-v3/3.0.0-beta.1/clap_v3/index.html

but I couldn't find that 'default_missing_value' reference and usage example.
please more infomation, if you ok.

[pksunkara]

default_value and default_missing_value