Enum simpleargs::UsageError

pub enum UsageError<T> {
    InvalidArgument {
        arg: T,
    },
    UnexpectedArgument {
        arg: T,
    },
    MissingArgument {
        name: String,
    },
    InvalidOption {
        name: String,
        value: Option<T>,
        err: OptionError,
    },
}

A command-line usage error, for when the user has passed incorrect arguments to the program.

Variants

InvalidArgument

Indicates an argument has invalid syntax. Used for arguments which cannot be parsed.

Fields of InvalidArgument

arg: T

Full text of the argument.

UnexpectedArgument

Indicates an argument was unexpected. Used for positional arguments.

Fields of UnexpectedArgument

arg: T

Full text of the argument.

MissingArgument

Indicates an expected positional argument was missing.

Fields of MissingArgument

name: String

The name of the argument.

InvalidOption

Indicates an invalid named argument.

Fields of InvalidOption

name: String

The name of the option without any leading dashes.

value: Option<T>

The option parameter value, if it exists.

err: OptionError

The inner error from parsing the option.

Trait Implementations

impl<T: Debug> Debug for UsageError<T>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<T> Display for UsageError<T> where
    T: Debug, 

fn fmt(&self, f: &mut Formatter) -> FmtResult

Formats the value using the given formatter.

impl<T> Error for UsageError<T> where
    T: Debug, 

fn source(&self) -> Option<&(dyn Error + 'static)>

The lower-level source of this error, if any.

fn backtrace(&self) -> Option<&Backtrace>

🔬 This is a nightly-only experimental API. (backtrace)

Returns a stack backtrace, if available, of where this error occurred.

fn description(&self) -> &str

Deprecated since 1.42.0:

use the Display impl or to_string()

if let Err(e) = "xc".parse::<u32>() { // Print e itself, no need for description(). eprintln!("Error: {}", e); }

fn cause(&self) -> Option<&dyn Error>

Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting