clap/examples/tutorial_builder/03_01_flag_count.rs

// Note: this requires the `cargo` feature

use clap::{arg, command, ArgAction};

fn main() {
    let matches = command!()
        .arg(arg!(-v - -verbose).action(ArgAction::Count))
        .get_matches();

    println!(
        "verbose: {:?}",
        matches
            .get_one::<u8>("verbose")
            .expect("Count always defaulted")
    );
}
docs: Annotate more places with required features 2022-03-03 18:32:29 +00:00			// Note: this requires the `cargo` feature

fix(parser): Deprecate occurrences_of This mostly exist for - Knowing of the value came from the command-line but we now have `ArgMatches::source` - Counting the number of flags but we now have `ArgAction::Count` 2022-06-06 17:35:00 +00:00			`use clap::{arg, command, ArgAction};`
docs: Re-work examples This creates distinct tutorial examples from complex feature examples (more how-tos). Both sets are getting builder / derive versions (at least the critical ones). 2021-11-30 18:30:19 +00:00
			`fn main() {`
fix(parser): Deprecate occurrences_of This mostly exist for - Knowing of the value came from the command-line but we now have `ArgMatches::source` - Counting the number of flags but we now have `ArgAction::Count` 2022-06-06 17:35:00 +00:00			`let matches = command!()`
			`.arg(arg!(-v - -verbose).action(ArgAction::Count))`
			`.get_matches();`
docs: Re-work examples This creates distinct tutorial examples from complex feature examples (more how-tos). Both sets are getting builder / derive versions (at least the critical ones). 2021-11-30 18:30:19 +00:00
fix(parser): Deprecate occurrences_of This mostly exist for - Knowing of the value came from the command-line but we now have `ArgMatches::source` - Counting the number of flags but we now have `ArgAction::Count` 2022-06-06 17:35:00 +00:00			`println!(`
			`"verbose: {:?}",`
			`matches`
perf(parser): Take up less memory with ArgAction::Count Someone should not reasonably expect a coun flag to go up to billions, millions, or even thousands. 255 should be sufficient for anyone, right? The original type was selected to be consistent with `ArgMatches::occurrences_of` but that is also used for tracking how many values appear which can be large with `xargs`. I'm still conflicted on what the "right type" is an wish we could support any numeric type. When I did a search on github though, every case was for debug/quiet flags and only supported 2-3 occurrences, making a `u8` overkill. This came out of a discussion on #3792 2022-06-09 16:09:36 +00:00			`.get_one::<u8>("verbose")`
fix(parser): Deprecate occurrences_of This mostly exist for - Knowing of the value came from the command-line but we now have `ArgMatches::source` - Counting the number of flags but we now have `ArgAction::Count` 2022-06-06 17:35:00 +00:00			`.expect("Count always defaulted")`
			`);`
docs: Re-work examples This creates distinct tutorial examples from complex feature examples (more how-tos). Both sets are getting builder / derive versions (at least the critical ones). 2021-11-30 18:30:19 +00:00			`}`