Struct gflags::Flag

pub struct Flag<T> { /* fields omitted */ }

The state associated with a single flag.

An invocation of gflags::define! with flag long name --the_name and flag type T declares an item static the_name: Flag<T> through which the state of the flag can be accessed.

After gflags::parse() has been called, the value of a flag is available through its .flag field which is of type T.

Examples

use std::path::Path;

gflags::define! {
    /// Search for patterns from the given file, with one pattern per line.
    -f, --file: &Path
}

fn main() {
    let patterns = gflags::parse();

    if FILE.is_present() {
        let path = FILE.flag;
        println!("searching for patterns from file: {}", path.display());
    } else {
        println!("searching for patterns given on command line: {:?}", patterns);
    }
}

Methods

impl<T: 'static> Flag<T>

pub fn is_present(&self) -> bool

Whether this flag was provided on the command line.

When using flags for which a default value is not provided, be sure to check .is_present() because accessing .flag when not present will cause a panic.

When a flag has a default value and is not passed on the command line, is_present() will be false and .flag will refer to the default value.

Trait Implementations

impl<T: 'static> Deref for Flag<T>

type Target = Accessor<T>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.