| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/structopt-0.3.26/src/lib.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lib.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../structopt/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../structopt/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="comment">// Copyright 2018 Guillaume Pinot (@TeXitoi) <texitoi@texitoi.eu> |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| </span><span class="attribute">#![deny(missing_docs)] |
| #![forbid(unsafe_code)] |
| |
| </span><span class="doccomment">//! This crate defines the `StructOpt` trait and its custom derive. |
| //! |
| //! ## Maintenance |
| //! |
| //! As clap v3 is now out, and the structopt features are integrated |
| //! into (almost as-is), structopt is now in maintenance mode: no new |
| //! feature will be added. |
| //! |
| //! Bugs will be fixed, and documentation improvements will be accepted. |
| //! |
| //! ## Features |
| //! |
| //! If you want to disable all the `clap` features (colors, |
| //! suggestions, ..) add `default-features = false` to the `structopt` |
| //! dependency: |
| //! |
| //! ```toml |
| //! [dependencies] |
| //! structopt = { version = "0.3", default-features = false } |
| //! ``` |
| //! |
| //! Support for [`paw`](https://github.com/rust-cli/paw) (the |
| //! `Command line argument paw-rser abstraction for main`) is disabled |
| //! by default, but can be enabled in the `structopt` dependency |
| //! with the feature `paw`: |
| //! |
| //! ```toml |
| //! [dependencies] |
| //! structopt = { version = "0.3", features = [ "paw" ] } |
| //! paw = "1.0" |
| //! ``` |
| //! |
| //! # Table of Contents |
| //! |
| //! - [How to `derive(StructOpt)`](#how-to-derivestructopt) |
| //! - [Attributes](#attributes) |
| //! - [Raw methods](#raw-methods) |
| //! - [Magical methods](#magical-methods) |
| //! - Arguments |
| //! - [Type magic](#type-magic) |
| //! - [Specifying argument types](#specifying-argument-types) |
| //! - [Default values](#default-values) |
| //! - [Help messages](#help-messages) |
| //! - [Environment variable fallback](#environment-variable-fallback) |
| //! - [Skipping fields](#skipping-fields) |
| //! - [Subcommands](#subcommands) |
| //! - [Optional subcommands](#optional-subcommands) |
| //! - [External subcommands](#external-subcommands) |
| //! - [Flattening subcommands](#flattening-subcommands) |
| //! - [Flattening](#flattening) |
| //! - [Custom string parsers](#custom-string-parsers) |
| //! - [Generics](#generics) |
| //! |
| //! |
| //! |
| //! ## How to `derive(StructOpt)` |
| //! |
| //! First, let's look at the example: |
| //! |
| //! ``` |
| //! use std::path::PathBuf; |
| //! use structopt::StructOpt; |
| //! |
| //! #[derive(Debug, StructOpt)] |
| //! #[structopt(name = "example", about = "An example of StructOpt usage.")] |
| //! struct Opt { |
| //! /// Activate debug mode |
| //! // short and long flags (-d, --debug) will be deduced from the field's name |
| //! #[structopt(short, long)] |
| //! debug: bool, |
| //! |
| //! /// Set speed |
| //! // we don't want to name it "speed", need to look smart |
| //! #[structopt(short = "v", long = "velocity", default_value = "42")] |
| //! speed: f64, |
| //! |
| //! /// Input file |
| //! #[structopt(parse(from_os_str))] |
| //! input: PathBuf, |
| //! |
| //! /// Output file, stdout if not present |
| //! #[structopt(parse(from_os_str))] |
| //! output: Option<PathBuf>, |
| //! |
| //! /// Where to write the output: to `stdout` or `file` |
| //! #[structopt(short)] |
| //! out_type: String, |
| //! |
| //! /// File name: only required when `out-type` is set to `file` |
| //! #[structopt(name = "FILE", required_if("out-type", "file"))] |
| //! file_name: Option<String>, |
| //! } |
| //! |
| //! fn main() { |
| //! # /* |
| //! let opt = Opt::from_args(); |
| //! # */ |
| //! # let opt = Opt::from_iter(&["binary", "-o", "stdout", "input"]); |
| //! println!("{:?}", opt); |
| //! } |
| //! ``` |
| //! |
| //! So `derive(StructOpt)` tells Rust to generate a command line parser, |
| //! and the various `structopt` attributes are simply |
| //! used for additional parameters. |
| //! |
| //! First, define a struct, whatever its name. This structure |
| //! corresponds to a `clap::App`, its fields correspond to `clap::Arg` |
| //! (unless they're [subcommands](#subcommands)), |
| //! and you can adjust these apps and args by `#[structopt(...)]` [attributes](#attributes). |
| //! |
| //! **Note:** |
| //! _________________ |
| //! Keep in mind that `StructOpt` trait is more than just `from_args` method. |
| //! It has a number of additional features, including access to underlying |
| //! `clap::App` via `StructOpt::clap()`. See the |
| //! [trait's reference documentation](trait.StructOpt.html). |
| //! _________________ |
| //! |
| //! ## Attributes |
| //! |
| //! You can control the way `structopt` translates your struct into an actual |
| //! [`clap::App`] invocation via `#[structopt(...)]` attributes. |
| //! |
| //! The attributes fall into two categories: |
| //! - `structopt`'s own [magical methods](#magical-methods). |
| //! |
| //! They are used by `structopt` itself. They come mostly in |
| //! `attr = ["whatever"]` form, but some `attr(args...)` also exist. |
| //! |
| //! - [`raw` attributes](#raw-methods). |
| //! |
| //! They represent explicit `clap::Arg/App` method calls. |
| //! They are what used to be explicit `#[structopt(raw(...))]` attrs in pre-0.3 `structopt` |
| //! |
| //! Every `structopt attribute` looks like comma-separated sequence of methods: |
| //! ``` |
| //! # #[derive(structopt::StructOpt)] struct S { |
| //! # |
| //! #[structopt( |
| //! short, // method with no arguments - always magical |
| //! long = "--long-option", // method with one argument |
| //! required_if("out", "file"), // method with one and more args |
| //! parse(from_os_str = path::to::parser) // some magical methods have their own syntax |
| //! )] |
| //! # |
| //! # s: () } mod path { pub(crate) mod to { pub(crate) fn parser(_: &std::ffi::OsStr) {} }} |
| //! ``` |
| //! |
| //! `#[structopt(...)]` attributes can be placed on top of `struct`, `enum`, |
| //! `struct` field or `enum` variant. Attributes on top of `struct` or `enum` |
| //! represent `clap::App` method calls, field or variant attributes correspond |
| //! to `clap::Arg` method calls. |
| //! |
| //! In other words, the `Opt` struct from the example above |
| //! will be turned into this (*details omitted*): |
| //! |
| //! ``` |
| //! # use structopt::clap::{Arg, App}; |
| //! App::new("example") |
| //! .version("0.2.0") |
| //! .about("An example of StructOpt usage.") |
| //! .arg(Arg::with_name("debug") |
| //! .help("Activate debug mode") |
| //! .short("debug") |
| //! .long("debug")) |
| //! .arg(Arg::with_name("speed") |
| //! .help("Set speed") |
| //! .short("v") |
| //! .long("velocity") |
| //! .default_value("42")) |
| //! // and so on |
| //! # ; |
| //! ``` |
| //! |
| //! ## Raw methods |
| //! |
| //! They are the reason why `structopt` is so flexible. **Every and each method from |
| //! `clap::App/Arg` can be used this way!** See the [`clap::App` |
| //! methods](https://docs.rs/clap/2/clap/struct.App.html) and [`clap::Arg` |
| //! methods](https://docs.rs/clap/2/clap/struct.Arg.html). |
| //! |
| //! ``` |
| //! # #[derive(structopt::StructOpt)] struct S { |
| //! # |
| //! #[structopt( |
| //! global = true, // name = arg form, neat for one-arg methods |
| //! required_if("out", "file") // name(arg1, arg2, ...) form. |
| //! )] |
| //! # |
| //! # s: String } |
| //! ``` |
| //! |
| //! The first form can only be used for methods which take only one argument. |
| //! The second form must be used with multi-arg methods, but can also be used with |
| //! single-arg methods. These forms are identical otherwise. |
| //! |
| //! As long as `method_name` is not one of the magical methods - |
| //! it will be translated into a mere method call. |
| //! |
| //! **Note:** |
| //! _________________ |
| //! |
| //! "Raw methods" are direct replacement for pre-0.3 structopt's |
| //! `#[structopt(raw(...))]` attributes, any time you would have used a `raw()` attribute |
| //! in 0.2 you should use raw method in 0.3. |
| //! |
| //! Unfortunately, old raw attributes collide with `clap::Arg::raw` method. To explicitly |
| //! warn users of this change we allow `#[structopt(raw())]` only with `true` or `false` |
| //! literals (this method is supposed to be called only with `true` anyway). |
| //! __________________ |
| //! |
| //! ## Magical methods |
| //! |
| //! They are the reason why `structopt` is so easy to use and convenient in most cases. |
| //! Many of them have defaults, some of them get used even if not mentioned. |
| //! |
| //! Methods may be used on "top level" (on top of a `struct`, `enum` or `enum` variant) |
| //! and/or on "field-level" (on top of a `struct` field or *inside* of an enum variant). |
| //! Top level (non-magical) methods correspond to `App::method` calls, field-level methods |
| //! are `Arg::method` calls. |
| //! |
| //! ```ignore |
| //! #[structopt(top_level)] |
| //! struct Foo { |
| //! #[structopt(field_level)] |
| //! field: u32 |
| //! } |
| //! |
| //! #[structopt(top_level)] |
| //! enum Bar { |
| //! #[structopt(top_level)] |
| //! Pineapple { |
| //! #[structopt(field_level)] |
| //! chocolate: String |
| //! }, |
| //! |
| //! #[structopt(top_level)] |
| //! Orange, |
| //! } |
| //! ``` |
| //! |
| //! - `name`: `[name = expr]` |
| //! - On top level: `App::new(expr)`. |
| //! |
| //! The binary name displayed in help messages. Defaults to the crate name given by Cargo. |
| //! |
| //! - On field-level: `Arg::with_name(expr)`. |
| //! |
| //! The name for the argument the field stands for, this name appears in help messages. |
| //! Defaults to a name, deduced from a field, see also |
| //! [`rename_all`](#specifying-argument-types). |
| //! |
| //! - `version`: `[version = "version"]` |
| //! |
| //! Usable only on top level: `App::version("version" or env!(CARGO_PKG_VERSION))`. |
| //! |
| //! The version displayed in help messages. |
| //! Defaults to the crate version given by Cargo. If `CARGO_PKG_VERSION` is not |
| //! set no `.version()` calls will be generated unless requested. |
| //! |
| //! - `no_version`: `no_version` |
| //! |
| //! Usable only on top level. Prevents default `App::version` call, i.e |
| //! when no `version = "version"` mentioned. |
| //! |
| //! - `author`: `author [= "author"]` |
| //! |
| //! Usable only on top level: `App::author("author" or env!(CARGO_PKG_AUTHORS))`. |
| //! |
| //! Author/maintainer of the binary, this name appears in help messages. |
| //! Defaults to the crate author given by cargo, but only when `author` explicitly mentioned. |
| //! |
| //! - `about`: `about [= "about"]` |
| //! |
| //! Usable only on top level: `App::about("about" or env!(CARGO_PKG_DESCRIPTION))`. |
| //! |
| //! Short description of the binary, appears in help messages. |
| //! Defaults to the crate description given by cargo, |
| //! but only when `about` explicitly mentioned. |
| //! |
| //! - [`short`](#specifying-argument-types): `short [= "short-opt-name"]` |
| //! |
| //! Usable only on field-level. |
| //! |
| //! - [`long`](#specifying-argument-types): `long [= "long-opt-name"]` |
| //! |
| //! Usable only on field-level. |
| //! |
| //! - [`default_value`](#default-values): `default_value [= "default value"]` |
| //! |
| //! Usable only on field-level. |
| //! |
| //! - [`rename_all`](#specifying-argument-types): |
| //! [`rename_all = "kebab"/"snake"/"screaming-snake"/"camel"/"pascal"/"verbatim"/"lower"/"upper"]` |
| //! |
| //! Usable both on top level and field level. |
| //! |
| //! - [`parse`](#custom-string-parsers): `parse(type [= path::to::parser::fn])` |
| //! |
| //! Usable only on field-level. |
| //! |
| //! - [`skip`](#skipping-fields): `skip [= expr]` |
| //! |
| //! Usable only on field-level. |
| //! |
| //! - [`flatten`](#flattening): `flatten` |
| //! |
| //! Usable on field-level or single-typed tuple variants. |
| //! |
| //! - [`subcommand`](#subcommands): `subcommand` |
| //! |
| //! Usable only on field-level. |
| //! |
| //! - [`external_subcommand`](#external-subcommands) |
| //! |
| //! Usable only on enum variants. |
| //! |
| //! - [`env`](#environment-variable-fallback): `env [= str_literal]` |
| //! |
| //! Usable only on field-level. |
| //! |
| //! - [`rename_all_env`](#auto-deriving-environment-variables): |
| //! [`rename_all_env = "kebab"/"snake"/"screaming-snake"/"camel"/"pascal"/"verbatim"/"lower"/"upper"]` |
| //! |
| //! Usable both on top level and field level. |
| //! |
| //! - [`verbatim_doc_comment`](#doc-comment-preprocessing-and-structoptverbatim_doc_comment): |
| //! `verbatim_doc_comment` |
| //! |
| //! Usable both on top level and field level. |
| //! |
| //! ## Type magic |
| //! |
| //! One of major things that makes `structopt` so awesome is its type magic. |
| //! Do you want optional positional argument? Use `Option<T>`! Or perhaps optional argument |
| //! that optionally takes value (`[--opt=[val]]`)? Use `Option<Option<T>>`! |
| //! |
| //! Here is the table of types and `clap` methods they correspond to: |
| //! |
| //! Type | Effect | Added method call to `clap::Arg` |
| //! -----------------------------|---------------------------------------------------|-------------------------------------- |
| //! `bool` | `true` if the flag is present | `.takes_value(false).multiple(false)` |
| //! `Option<T: FromStr>` | optional positional argument or option | `.takes_value(true).multiple(false)` |
| //! `Option<Option<T: FromStr>>` | optional option with optional value | `.takes_value(true).multiple(false).min_values(0).max_values(1)` |
| //! `Vec<T: FromStr>` | list of options or the other positional arguments | `.takes_value(true).multiple(true)` |
| //! `Option<Vec<T: FromStr>` | optional list of options | `.takes_values(true).multiple(true).min_values(0)` |
| //! `T: FromStr` | required option or positional argument | `.takes_value(true).multiple(false).required(!has_default)` |
| //! |
| //! The `FromStr` trait is used to convert the argument to the given |
| //! type, and the `Arg::validator` method is set to a method using |
| //! `to_string()` (`FromStr::Err` must implement `std::fmt::Display`). |
| //! If you would like to use a custom string parser other than `FromStr`, see |
| //! the [same titled section](#custom-string-parsers) below. |
| //! |
| //! **Important:** |
| //! _________________ |
| //! Pay attention that *only literal occurrence* of this types is special, for example |
| //! `Option<T>` is special while `::std::option::Option<T>` is not. |
| //! |
| //! If you need to avoid special casing you can make a `type` alias and |
| //! use it in place of the said type. |
| //! _________________ |
| //! |
| //! **Note:** |
| //! _________________ |
| //! `bool` cannot be used as positional argument unless you provide an explicit parser. |
| //! If you need a positional bool, for example to parse `true` or `false`, you must |
| //! annotate the field with explicit [`#[structopt(parse(...))]`](#custom-string-parsers). |
| //! _________________ |
| //! |
| //! Thus, the `speed` argument is generated as: |
| //! |
| //! ``` |
| //! # fn parse_validator<T>(_: String) -> Result<(), String> { unimplemented!() } |
| //! clap::Arg::with_name("speed") |
| //! .takes_value(true) |
| //! .multiple(false) |
| //! .required(false) |
| //! .validator(parse_validator::<f64>) |
| //! .short("v") |
| //! .long("velocity") |
| //! .help("Set speed") |
| //! .default_value("42"); |
| //! ``` |
| //! |
| //! ## Specifying argument types |
| //! |
| //! There are three types of arguments that can be supplied to each |
| //! (sub-)command: |
| //! |
| //! - short (e.g. `-h`), |
| //! - long (e.g. `--help`) |
| //! - and positional. |
| //! |
| //! Like clap, structopt defaults to creating positional arguments. |
| //! |
| //! If you want to generate a long argument you can specify either |
| //! `long = $NAME`, or just `long` to get a long flag generated using |
| //! the field name. The generated casing style can be modified using |
| //! the `rename_all` attribute. See the `rename_all` example for more. |
| //! |
| //! For short arguments, `short` will use the first letter of the |
| //! field name by default, but just like the long option it's also |
| //! possible to use a custom letter through `short = $LETTER`. |
| //! |
| //! If an argument is renamed using `name = $NAME` any following call to |
| //! `short` or `long` will use the new name. |
| //! |
| //! **Attention**: If these arguments are used without an explicit name |
| //! the resulting flag is going to be renamed using `kebab-case` if the |
| //! `rename_all` attribute was not specified previously. The same is true |
| //! for subcommands with implicit naming through the related data structure. |
| //! |
| //! ``` |
| //! use structopt::StructOpt; |
| //! |
| //! #[derive(StructOpt)] |
| //! #[structopt(rename_all = "kebab-case")] |
| //! struct Opt { |
| //! /// This option can be specified with something like `--foo-option |
| //! /// value` or `--foo-option=value` |
| //! #[structopt(long)] |
| //! foo_option: String, |
| //! |
| //! /// This option can be specified with something like `-b value` (but |
| //! /// not `--bar-option value`). |
| //! #[structopt(short)] |
| //! bar_option: String, |
| //! |
| //! /// This option can be specified either `--baz value` or `-z value`. |
| //! #[structopt(short = "z", long = "baz")] |
| //! baz_option: String, |
| //! |
| //! /// This option can be specified either by `--custom value` or |
| //! /// `-c value`. |
| //! #[structopt(name = "custom", long, short)] |
| //! custom_option: String, |
| //! |
| //! /// This option is positional, meaning it is the first unadorned string |
| //! /// you provide (multiple others could follow). |
| //! my_positional: String, |
| //! |
| //! /// This option is skipped and will be filled with the default value |
| //! /// for its type (in this case 0). |
| //! #[structopt(skip)] |
| //! skipped: u32, |
| //! } |
| //! |
| //! # Opt::from_iter( |
| //! # &["test", "--foo-option", "", "-b", "", "--baz", "", "--custom", "", "positional"]); |
| //! ``` |
| //! |
| //! ## Default values |
| //! |
| //! In clap, default values for options can be specified via [`Arg::default_value`]. |
| //! |
| //! Of course, you can use as a raw method: |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! struct Opt { |
| //! #[structopt(default_value = "", long)] |
| //! prefix: String, |
| //! } |
| //! ``` |
| //! |
| //! This is quite mundane and error-prone to type the `"..."` default by yourself, |
| //! especially when the Rust ecosystem uses the [`Default`] trait for that. |
| //! It would be wonderful to have `structopt` to take the `Default_default` and fill it |
| //! for you. And yes, `structopt` can do that. |
| //! |
| //! Unfortunately, `default_value` takes `&str` but `Default::default` |
| //! gives us some `Self` value. We need to map `Self` to `&str` somehow. |
| //! |
| //! `structopt` solves this problem via [`ToString`] trait. |
| //! |
| //! To be able to use auto-default the type must implement *both* `Default` and `ToString`: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! struct Opt { |
| //! // just leave the `= "..."` part and structopt will figure it for you |
| //! #[structopt(default_value, long)] |
| //! prefix: String, // `String` implements both `Default` and `ToString` |
| //! } |
| //! ``` |
| //! |
| //! [`Default`]: https://doc.rust-lang.org/std/default/trait.Default.html |
| //! [`ToString`]: https://doc.rust-lang.org/std/string/trait.ToString.html |
| //! [`Arg::default_value`]: https://docs.rs/clap/2.33.0/clap/struct.Arg.html#method.default_value |
| //! |
| //! |
| //! ## Help messages |
| //! |
| //! In clap, help messages for the whole binary can be specified |
| //! via [`App::about`] and [`App::long_about`] while help messages |
| //! for individual arguments can be specified via [`Arg::help`] and [`Arg::long_help`]". |
| //! |
| //! `long_*` variants are used when user calls the program with |
| //! `--help` and "short" variants are used with `-h` flag. In `structopt`, |
| //! you can use them via [raw methods](#raw-methods), for example: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! |
| //! #[derive(StructOpt)] |
| //! #[structopt(about = "I am a program and I work, just pass `-h`")] |
| //! struct Foo { |
| //! #[structopt(short, help = "Pass `-h` and you'll see me!")] |
| //! bar: String, |
| //! } |
| //! ``` |
| //! |
| //! For convenience, doc comments can be used instead of raw methods |
| //! (this example works exactly like the one above): |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! |
| //! #[derive(StructOpt)] |
| //! /// I am a program and I work, just pass `-h` |
| //! struct Foo { |
| //! /// Pass `-h` and you'll see me! |
| //! bar: String, |
| //! } |
| //! ``` |
| //! |
| //! Doc comments on [top-level](#magical-methods) will be turned into |
| //! `App::about/long_about` call (see below), doc comments on field-level are |
| //! `Arg::help/long_help` calls. |
| //! |
| //! **Important:** |
| //! _________________ |
| //! |
| //! Raw methods have priority over doc comments! |
| //! |
| //! **Top level doc comments always generate `App::about/long_about` calls!** |
| //! If you really want to use the `App::help/long_help` methods (you likely don't), |
| //! use a raw method to override the `App::about` call generated from the doc comment. |
| //! __________________ |
| //! |
| //! ### `long_help` and `--help` |
| //! |
| //! A message passed to [`App::long_about`] or [`Arg::long_help`] will be displayed whenever |
| //! your program is called with `--help` instead of `-h`. Of course, you can |
| //! use them via raw methods as described [above](#help-messages). |
| //! |
| //! The more convenient way is to use a so-called "long" doc comment: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! /// Hi there, I'm Robo! |
| //! /// |
| //! /// I like beeping, stumbling, eating your electricity, |
| //! /// and making records of you singing in a shower. |
| //! /// Pay up, or I'll upload it to youtube! |
| //! struct Robo { |
| //! /// Call my brother SkyNet. |
| //! /// |
| //! /// I am artificial superintelligence. I won't rest |
| //! /// until I'll have destroyed humanity. Enjoy your |
| //! /// pathetic existence, you mere mortals. |
| //! #[structopt(long)] |
| //! kill_all_humans: bool, |
| //! } |
| //! ``` |
| //! |
| //! A long doc comment consists of three parts: |
| //! * Short summary |
| //! * A blank line (whitespace only) |
| //! * Detailed description, all the rest |
| //! |
| //! In other words, "long" doc comment consists of two or more paragraphs, |
| //! with the first being a summary and the rest being the detailed description. |
| //! |
| //! **A long comment will result in two method calls**, `help(<summary>)` and |
| //! `long_help(<whole comment>)`, so clap will display the summary with `-h` |
| //! and the whole help message on `--help` (see below). |
| //! |
| //! So, the example above will be turned into this (details omitted): |
| //! ``` |
| //! clap::App::new("<name>") |
| //! .about("Hi there, I'm Robo!") |
| //! .long_about("Hi there, I'm Robo!\n\n\ |
| //! I like beeping, stumbling, eating your electricity,\ |
| //! and making records of you singing in a shower.\ |
| //! Pay up or I'll upload it to youtube!") |
| //! // args... |
| //! # ; |
| //! ``` |
| //! |
| //! ### `-h` vs `--help` (A.K.A `help()` vs `long_help()`) |
| //! |
| //! The `-h` flag is not the same as `--help`. |
| //! |
| //! -h corresponds to `Arg::help/App::about` and requests short "summary" messages |
| //! while --help corresponds to `Arg::long_help/App::long_about` and requests more |
| //! detailed, descriptive messages. |
| //! |
| //! It is entirely up to `clap` what happens if you used only one of |
| //! [`Arg::help`]/[`Arg::long_help`], see `clap`'s documentation for these methods. |
| //! |
| //! As of clap v2.33, if only a short message ([`Arg::help`]) or only |
| //! a long ([`Arg::long_help`]) message is provided, clap will use it |
| //! for both -h and --help. The same logic applies to `about/long_about`. |
| //! |
| //! ### Doc comment preprocessing and `#[structopt(verbatim_doc_comment)]` |
| //! |
| //! `structopt` applies some preprocessing to doc comments to ease the most common uses: |
| //! |
| //! * Strip leading and trailing whitespace from every line, if present. |
| //! |
| //! * Strip leading and trailing blank lines, if present. |
| //! |
| //! * Interpret each group of non-empty lines as a word-wrapped paragraph. |
| //! |
| //! We replace newlines within paragraphs with spaces to allow the output |
| //! to be re-wrapped to the terminal width. |
| //! |
| //! * Strip any excess blank lines so that there is exactly one per paragraph break. |
| //! |
| //! * If the first paragraph ends in exactly one period, |
| //! remove the trailing period (i.e. strip trailing periods but not trailing ellipses). |
| //! |
| //! Sometimes you don't want this preprocessing to apply, for example the comment contains |
| //! some ASCII art or markdown tables, you would need to preserve LFs along with |
| //! blank lines and the leading/trailing whitespace. You can ask `structopt` to preserve them |
| //! via `#[structopt(verbatim_doc_comment)]` attribute. |
| //! |
| //! **This attribute must be applied to each field separately**, there's no global switch. |
| //! |
| //! **Important:** |
| //! ______________ |
| //! Keep in mind that `structopt` will *still* remove one leading space from each |
| //! line, even if this attribute is present, to allow for a space between |
| //! `///` and the content. |
| //! |
| //! Also, `structopt` will *still* remove leading and trailing blank lines so |
| //! these formats are equivalent: |
| //! |
| //! ``` |
| //! /** This is a doc comment |
| //! |
| //! Hello! */ |
| //! |
| //! /** |
| //! This is a doc comment |
| //! |
| //! Hello! |
| //! */ |
| //! |
| //! /// This is a doc comment |
| //! /// |
| //! /// Hello! |
| //! # |
| //! # mod m {} |
| //! ``` |
| //! ______________ |
| //! |
| //! [`App::about`]: https://docs.rs/clap/2/clap/struct.App.html#method.about |
| //! [`App::long_about`]: https://docs.rs/clap/2/clap/struct.App.html#method.long_about |
| //! [`Arg::help`]: https://docs.rs/clap/2/clap/struct.Arg.html#method.help |
| //! [`Arg::long_help`]: https://docs.rs/clap/2/clap/struct.Arg.html#method.long_help |
| //! |
| //! ## Environment variable fallback |
| //! |
| //! It is possible to specify an environment variable fallback option for an arguments |
| //! so that its value is taken from the specified environment variable if not |
| //! given through the command-line: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! |
| //! #[derive(StructOpt)] |
| //! struct Foo { |
| //! #[structopt(short, long, env = "PARAMETER_VALUE")] |
| //! parameter_value: String, |
| //! } |
| //! ``` |
| //! |
| //! By default, values from the environment are shown in the help output (i.e. when invoking |
| //! `--help`): |
| //! |
| //! ```shell |
| //! $ cargo run -- --help |
| //! ... |
| //! OPTIONS: |
| //! -p, --parameter-value <parameter-value> [env: PARAMETER_VALUE=env_value] |
| //! ``` |
| //! |
| //! In some cases this may be undesirable, for example when being used for passing |
| //! credentials or secret tokens. In those cases you can use `hide_env_values` to avoid |
| //! having structopt emit the actual secret values: |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! |
| //! #[derive(StructOpt)] |
| //! struct Foo { |
| //! #[structopt(long = "secret", env = "SECRET_VALUE", hide_env_values = true)] |
| //! secret_value: String, |
| //! } |
| //! ``` |
| //! |
| //! ### Auto-deriving environment variables |
| //! |
| //! Environment variables tend to be called after the corresponding `struct`'s field, |
| //! as in example above. The field is `secret_value` and the env var is "SECRET_VALUE"; |
| //! the name is the same, except casing is different. |
| //! |
| //! It's pretty tedious and error-prone to type the same name twice, |
| //! so you can ask `structopt` to do that for you. |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! |
| //! #[derive(StructOpt)] |
| //! struct Foo { |
| //! #[structopt(long = "secret", env)] |
| //! secret_value: String, |
| //! } |
| //! ``` |
| //! |
| //! It works just like `#[structopt(short/long)]`: if `env` is not set to some concrete |
| //! value the value will be derived from the field's name. This is controlled by |
| //! `#[structopt(rename_all_env)]`. |
| //! |
| //! `rename_all_env` works exactly as `rename_all` (including overriding) |
| //! except default casing is `SCREAMING_SNAKE_CASE` instead of `kebab-case`. |
| //! |
| //! ## Skipping fields |
| //! |
| //! Sometimes you may want to add a field to your `Opt` struct that is not |
| //! a command line option and `clap` should know nothing about it. You can ask |
| //! `structopt` to skip the field entirely via `#[structopt(skip = value)]` |
| //! (`value` must implement `Into<FieldType>`) |
| //! or `#[structopt(skip)]` if you want assign the field with `Default::default()` |
| //! (obviously, the field's type must implement `Default`). |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! pub struct Opt { |
| //! #[structopt(long, short)] |
| //! number: u32, |
| //! |
| //! // these fields are to be assigned with Default::default() |
| //! |
| //! #[structopt(skip)] |
| //! k: String, |
| //! #[structopt(skip)] |
| //! v: Vec<u32>, |
| //! |
| //! // these fields get set explicitly |
| //! |
| //! #[structopt(skip = vec![1, 2, 3])] |
| //! k2: Vec<u32>, |
| //! #[structopt(skip = "cake")] // &str implements Into<String> |
| //! v2: String, |
| //! } |
| //! ``` |
| //! |
| //! ## Subcommands |
| //! |
| //! Some applications, especially large ones, split their functionality |
| //! through the use of "subcommands". Each of these act somewhat like a separate |
| //! command, but is part of the larger group. |
| //! One example is `git`, which has subcommands such as `add`, `commit`, |
| //! and `clone`, to mention just a few. |
| //! |
| //! `clap` has this functionality, and `structopt` supports it through enums: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! |
| //! # use std::path::PathBuf; |
| //! #[derive(StructOpt)] |
| //! #[structopt(about = "the stupid content tracker")] |
| //! enum Git { |
| //! Add { |
| //! #[structopt(short)] |
| //! interactive: bool, |
| //! #[structopt(short)] |
| //! patch: bool, |
| //! #[structopt(parse(from_os_str))] |
| //! files: Vec<PathBuf>, |
| //! }, |
| //! Fetch { |
| //! #[structopt(long)] |
| //! dry_run: bool, |
| //! #[structopt(long)] |
| //! all: bool, |
| //! repository: Option<String>, |
| //! }, |
| //! Commit { |
| //! #[structopt(short)] |
| //! message: Option<String>, |
| //! #[structopt(short)] |
| //! all: bool, |
| //! }, |
| //! } |
| //! ``` |
| //! |
| //! Using `derive(StructOpt)` on an enum instead of a struct will produce |
| //! a `clap::App` that only takes subcommands. So `git add`, `git fetch`, |
| //! and `git commit` would be commands allowed for the above example. |
| //! |
| //! `structopt` also provides support for applications where certain flags |
| //! need to apply to all subcommands, as well as nested subcommands: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! struct MakeCookie { |
| //! #[structopt(name = "supervisor", default_value = "Puck", long = "supervisor")] |
| //! supervising_faerie: String, |
| //! /// The faerie tree this cookie is being made in. |
| //! tree: Option<String>, |
| //! #[structopt(subcommand)] // Note that we mark a field as a subcommand |
| //! cmd: Command, |
| //! } |
| //! |
| //! #[derive(StructOpt)] |
| //! enum Command { |
| //! /// Pound acorns into flour for cookie dough. |
| //! Pound { |
| //! acorns: u32, |
| //! }, |
| //! /// Add magical sparkles -- the secret ingredient! |
| //! Sparkle { |
| //! #[structopt(short, parse(from_occurrences))] |
| //! magicality: u64, |
| //! #[structopt(short)] |
| //! color: String, |
| //! }, |
| //! Finish(Finish), |
| //! } |
| //! |
| //! // Subcommand can also be externalized by using a 1-uple enum variant |
| //! #[derive(StructOpt)] |
| //! struct Finish { |
| //! #[structopt(short)] |
| //! time: u32, |
| //! #[structopt(subcommand)] // Note that we mark a field as a subcommand |
| //! finish_type: FinishType, |
| //! } |
| //! |
| //! // subsubcommand! |
| //! #[derive(StructOpt)] |
| //! enum FinishType { |
| //! Glaze { |
| //! applications: u32, |
| //! }, |
| //! Powder { |
| //! flavor: String, |
| //! dips: u32, |
| //! } |
| //! } |
| //! ``` |
| //! |
| //! Marking a field with `structopt(subcommand)` will add the subcommands of the |
| //! designated enum to the current `clap::App`. The designated enum *must* also |
| //! be derived `StructOpt`. So the above example would take the following |
| //! commands: |
| //! |
| //! + `make-cookie pound 50` |
| //! + `make-cookie sparkle -mmm --color "green"` |
| //! + `make-cookie finish 130 glaze 3` |
| //! |
| //! ### Optional subcommands |
| //! |
| //! Subcommands may be optional: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! struct Foo { |
| //! file: String, |
| //! #[structopt(subcommand)] |
| //! cmd: Option<Command>, |
| //! } |
| //! |
| //! #[derive(StructOpt)] |
| //! enum Command { |
| //! Bar, |
| //! Baz, |
| //! Quux, |
| //! } |
| //! ``` |
| //! |
| //! ### External subcommands |
| //! |
| //! Sometimes you want to support not only the set of well-known subcommands |
| //! but you also want to allow other, user-driven subcommands. `clap` supports |
| //! this via [`AppSettings::AllowExternalSubcommands`]. |
| //! |
| //! `structopt` provides it's own dedicated syntax for that: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(Debug, PartialEq, StructOpt)] |
| //! struct Opt { |
| //! #[structopt(subcommand)] |
| //! sub: Subcommands, |
| //! } |
| //! |
| //! #[derive(Debug, PartialEq, StructOpt)] |
| //! enum Subcommands { |
| //! // normal subcommand |
| //! Add, |
| //! |
| //! // `external_subcommand` tells structopt to put |
| //! // all the extra arguments into this Vec |
| //! #[structopt(external_subcommand)] |
| //! Other(Vec<String>), |
| //! } |
| //! |
| //! // normal subcommand |
| //! assert_eq!( |
| //! Opt::from_iter(&["test", "add"]), |
| //! Opt { |
| //! sub: Subcommands::Add |
| //! } |
| //! ); |
| //! |
| //! assert_eq!( |
| //! Opt::from_iter(&["test", "git", "status"]), |
| //! Opt { |
| //! sub: Subcommands::Other(vec!["git".into(), "status".into()]) |
| //! } |
| //! ); |
| //! |
| //! // Please note that if you'd wanted to allow "no subcommands at all" case |
| //! // you should have used `sub: Option<Subcommands>` above |
| //! assert!(Opt::from_iter_safe(&["test"]).is_err()); |
| //! ``` |
| //! |
| //! In other words, you just add an extra tuple variant marked with |
| //! `#[structopt(subcommand)]`, and its type must be either |
| //! `Vec<String>` or `Vec<OsString>`. `structopt` will detect `String` in this context |
| //! and use appropriate `clap` API. |
| //! |
| //! [`AppSettings::AllowExternalSubcommands`]: https://docs.rs/clap/2.32.0/clap/enum.AppSettings.html#variant.AllowExternalSubcommands |
| //! |
| //! ### Flattening subcommands |
| //! |
| //! It is also possible to combine multiple enums of subcommands into one. |
| //! All the subcommands will be on the same level. |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! enum BaseCli { |
| //! Ghost10 { |
| //! arg1: i32, |
| //! } |
| //! } |
| //! |
| //! #[derive(StructOpt)] |
| //! enum Opt { |
| //! #[structopt(flatten)] |
| //! BaseCli(BaseCli), |
| //! Dex { |
| //! arg2: i32, |
| //! }, |
| //! } |
| //! ``` |
| //! |
| //! ```shell |
| //! cli ghost10 42 |
| //! cli dex 42 |
| //! ``` |
| //! |
| //! ## Flattening |
| //! |
| //! It can sometimes be useful to group related arguments in a substruct, |
| //! while keeping the command-line interface flat. In these cases you can mark |
| //! a field as `flatten` and give it another type that derives `StructOpt`: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! #[derive(StructOpt)] |
| //! struct Cmdline { |
| //! /// switch on verbosity |
| //! #[structopt(short)] |
| //! verbose: bool, |
| //! #[structopt(flatten)] |
| //! daemon_opts: DaemonOpts, |
| //! } |
| //! |
| //! #[derive(StructOpt)] |
| //! struct DaemonOpts { |
| //! /// daemon user |
| //! #[structopt(short)] |
| //! user: String, |
| //! /// daemon group |
| //! #[structopt(short)] |
| //! group: String, |
| //! } |
| //! ``` |
| //! |
| //! In this example, the derived `Cmdline` parser will support the options `-v`, |
| //! `-u` and `-g`. |
| //! |
| //! This feature also makes it possible to define a `StructOpt` struct in a |
| //! library, parse the corresponding arguments in the main argument parser, and |
| //! pass off this struct to a handler provided by that library. |
| //! |
| //! ## Custom string parsers |
| //! |
| //! If the field type does not have a `FromStr` implementation, or you would |
| //! like to provide a custom parsing scheme other than `FromStr`, you may |
| //! provide a custom string parser using `parse(...)` like this: |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! use std::num::ParseIntError; |
| //! use std::path::PathBuf; |
| //! |
| //! fn parse_hex(src: &str) -> Result<u32, ParseIntError> { |
| //! u32::from_str_radix(src, 16) |
| //! } |
| //! |
| //! #[derive(StructOpt)] |
| //! struct HexReader { |
| //! #[structopt(short, parse(try_from_str = parse_hex))] |
| //! number: u32, |
| //! #[structopt(short, parse(from_os_str))] |
| //! output: PathBuf, |
| //! } |
| //! ``` |
| //! |
| //! There are five kinds of custom parsers: |
| //! |
| //! | Kind | Signature | Default | |
| //! |-------------------|---------------------------------------|---------------------------------| |
| //! | `from_str` | `fn(&str) -> T` | `::std::convert::From::from` | |
| //! | `try_from_str` | `fn(&str) -> Result<T, E>` | `::std::str::FromStr::from_str` | |
| //! | `from_os_str` | `fn(&OsStr) -> T` | `::std::convert::From::from` | |
| //! | `try_from_os_str` | `fn(&OsStr) -> Result<T, OsString>` | (no default function) | |
| //! | `from_occurrences`| `fn(u64) -> T` | `value as T` | |
| //! | `from_flag` | `fn(bool) -> T` | `::std::convert::From::from` | |
| //! |
| //! The `from_occurrences` parser is special. Using `parse(from_occurrences)` |
| //! results in the _number of flags occurrences_ being stored in the relevant |
| //! field or being passed to the supplied function. In other words, it converts |
| //! something like `-vvv` to `3`. This is equivalent to |
| //! `.takes_value(false).multiple(true)`. Note that the default parser can only |
| //! be used with fields of integer types (`u8`, `usize`, `i64`, etc.). |
| //! |
| //! The `from_flag` parser is also special. Using `parse(from_flag)` or |
| //! `parse(from_flag = some_func)` will result in the field being treated as a |
| //! flag even if it does not have type `bool`. |
| //! |
| //! When supplying a custom string parser, `bool` will not be treated specially: |
| //! |
| //! Type | Effect | Added method call to `clap::Arg` |
| //! ------------|-------------------|-------------------------------------- |
| //! `Option<T>` | optional argument | `.takes_value(true).multiple(false)` |
| //! `Vec<T>` | list of arguments | `.takes_value(true).multiple(true)` |
| //! `T` | required argument | `.takes_value(true).multiple(false).required(!has_default)` |
| //! |
| //! In the `try_from_*` variants, the function will run twice on valid input: |
| //! once to validate, and once to parse. Hence, make sure the function is |
| //! side-effect-free. |
| //! |
| //! ## Generics |
| //! |
| //! Generic structs and enums can be used. They require explicit trait bounds |
| //! on any generic types that will be used by the `StructOpt` derive macro. In |
| //! some cases, associated types will require additional bounds. See the usage |
| //! of `FromStr` below for an example of this. |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! use std::{fmt, str::FromStr}; |
| //! |
| //! // a struct with single custom argument |
| //! #[derive(StructOpt)] |
| //! struct GenericArgs<T: FromStr> where <T as FromStr>::Err: fmt::Display + fmt::Debug { |
| //! generic_arg_1: String, |
| //! generic_arg_2: String, |
| //! custom_arg_1: T, |
| //! } |
| //! ``` |
| //! |
| //! or |
| //! |
| //! ``` |
| //! # use structopt::StructOpt; |
| //! // a struct with multiple custom arguments in a substructure |
| //! #[derive(StructOpt)] |
| //! struct GenericArgs<T: StructOpt> { |
| //! generic_arg_1: String, |
| //! generic_arg_2: String, |
| //! #[structopt(flatten)] |
| //! custom_args: T, |
| //! } |
| //! ``` |
| |
| </span><span class="comment">// those mains are for a reason |
| </span><span class="attribute">#![allow(clippy::needless_doctest_main)] |
| |
| #[doc(hidden)] |
| </span><span class="kw">pub use </span>structopt_derive::<span class="kw-2">*</span>; |
| |
| <span class="kw">use </span>std::ffi::OsString; |
| |
| <span class="doccomment">/// Re-exports |
| </span><span class="kw">pub use </span>clap; |
| <span class="attribute">#[cfg(feature = <span class="string">"paw"</span>)] |
| </span><span class="kw">pub use </span>paw_dep <span class="kw">as </span>paw; |
| |
| <span class="doccomment">/// **This is NOT PUBLIC API**. |
| </span><span class="attribute">#[doc(hidden)] |
| </span><span class="kw">pub use </span>lazy_static; |
| |
| <span class="doccomment">/// A struct that is converted from command line arguments. |
| </span><span class="kw">pub trait </span>StructOpt { |
| <span class="doccomment">/// Returns [`clap::App`] corresponding to the struct. |
| </span><span class="kw">fn </span>clap<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>() -> clap::App<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>; |
| |
| <span class="doccomment">/// Builds the struct from [`clap::ArgMatches`]. It's guaranteed to succeed |
| /// if `matches` originates from an `App` generated by [`StructOpt::clap`] called on |
| /// the same type, otherwise it must panic. |
| </span><span class="kw">fn </span>from_clap(matches: <span class="kw-2">&</span>clap::ArgMatches<<span class="lifetime">'_</span>>) -> <span class="self">Self</span>; |
| |
| <span class="doccomment">/// Builds the struct from the command line arguments ([`std::env::args_os`]). |
| /// Calls [`clap::Error::exit`] on failure, printing the error message and aborting the program. |
| </span><span class="kw">fn </span>from_args() -> <span class="self">Self |
| </span><span class="kw">where |
| </span><span class="self">Self</span>: Sized, |
| { |
| <span class="self">Self</span>::from_clap(<span class="kw-2">&</span><span class="self">Self</span>::clap().get_matches()) |
| } |
| |
| <span class="doccomment">/// Builds the struct from the command line arguments ([`std::env::args_os`]). |
| /// Unlike [`StructOpt::from_args`], returns [`clap::Error`] on failure instead of aborting the program, |
| /// so calling [`.exit`][clap::Error::exit] is up to you. |
| </span><span class="kw">fn </span>from_args_safe() -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, clap::Error> |
| <span class="kw">where |
| </span><span class="self">Self</span>: Sized, |
| { |
| <span class="self">Self</span>::clap() |
| .get_matches_safe() |
| .map(|matches| <span class="self">Self</span>::from_clap(<span class="kw-2">&</span>matches)) |
| } |
| |
| <span class="doccomment">/// Gets the struct from any iterator such as a `Vec` of your making. |
| /// Print the error message and quit the program in case of failure. |
| /// |
| /// **NOTE**: The first argument will be parsed as the binary name unless |
| /// [`clap::AppSettings::NoBinaryName`] has been used. |
| </span><span class="kw">fn </span>from_iter<I>(iter: I) -> <span class="self">Self |
| </span><span class="kw">where |
| </span><span class="self">Self</span>: Sized, |
| I: IntoIterator, |
| I::Item: Into<OsString> + Clone, |
| { |
| <span class="self">Self</span>::from_clap(<span class="kw-2">&</span><span class="self">Self</span>::clap().get_matches_from(iter)) |
| } |
| |
| <span class="doccomment">/// Gets the struct from any iterator such as a `Vec` of your making. |
| /// |
| /// Returns a [`clap::Error`] in case of failure. This does *not* exit in the |
| /// case of `--help` or `--version`, to achieve the same behavior as |
| /// [`from_iter()`][StructOpt::from_iter] you must call [`.exit()`][clap::Error::exit] on the error value. |
| /// |
| /// **NOTE**: The first argument will be parsed as the binary name unless |
| /// [`clap::AppSettings::NoBinaryName`] has been used. |
| </span><span class="kw">fn </span>from_iter_safe<I>(iter: I) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, clap::Error> |
| <span class="kw">where |
| </span><span class="self">Self</span>: Sized, |
| I: IntoIterator, |
| I::Item: Into<OsString> + Clone, |
| { |
| <span class="prelude-val">Ok</span>(<span class="self">Self</span>::from_clap(<span class="kw-2">&</span><span class="self">Self</span>::clap().get_matches_from_safe(iter)<span class="question-mark">?</span>)) |
| } |
| } |
| |
| <span class="doccomment">/// This trait is NOT API. **SUBJECT TO CHANGE WITHOUT NOTICE!**. |
| </span><span class="attribute">#[doc(hidden)] |
| </span><span class="kw">pub trait </span>StructOptInternal: StructOpt { |
| <span class="kw">fn </span>augment_clap<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>(app: clap::App<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>) -> clap::App<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>> { |
| app |
| } |
| |
| <span class="kw">fn </span>is_subcommand() -> bool { |
| <span class="bool-val">false |
| </span>} |
| |
| <span class="kw">fn </span>from_subcommand<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>(_sub: (<span class="kw-2">&</span><span class="lifetime">'b </span>str, <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'b </span>clap::ArgMatches<<span class="lifetime">'a</span>>>)) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> |
| <span class="kw">where |
| </span><span class="self">Self</span>: std::marker::Sized, |
| { |
| <span class="prelude-val">None |
| </span>} |
| } |
| |
| <span class="kw">impl</span><T: StructOpt> StructOpt <span class="kw">for </span>Box<T> { |
| <span class="kw">fn </span>clap<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>() -> clap::App<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>> { |
| <T <span class="kw">as </span>StructOpt>::clap() |
| } |
| |
| <span class="kw">fn </span>from_clap(matches: <span class="kw-2">&</span>clap::ArgMatches<<span class="lifetime">'_</span>>) -> <span class="self">Self </span>{ |
| Box::new(<T <span class="kw">as </span>StructOpt>::from_clap(matches)) |
| } |
| } |
| |
| <span class="kw">impl</span><T: StructOptInternal> StructOptInternal <span class="kw">for </span>Box<T> { |
| <span class="attribute">#[doc(hidden)] |
| </span><span class="kw">fn </span>is_subcommand() -> bool { |
| <T <span class="kw">as </span>StructOptInternal>::is_subcommand() |
| } |
| |
| <span class="attribute">#[doc(hidden)] |
| </span><span class="kw">fn </span>from_subcommand<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>(sub: (<span class="kw-2">&</span><span class="lifetime">'b </span>str, <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'b </span>clap::ArgMatches<<span class="lifetime">'a</span>>>)) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| <T <span class="kw">as </span>StructOptInternal>::from_subcommand(sub).map(Box::new) |
| } |
| |
| <span class="attribute">#[doc(hidden)] |
| </span><span class="kw">fn </span>augment_clap<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>(app: clap::App<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>>) -> clap::App<<span class="lifetime">'a</span>, <span class="lifetime">'b</span>> { |
| <T <span class="kw">as </span>StructOptInternal>::augment_clap(app) |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="structopt" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |