Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

18 files changed, 1157 insertions, 0 deletions

diff --git a/third_party/rust/clap/examples/tutorial_derive/01_quick.rs b/third_party/rust/clap/examples/tutorial_derive/01_quick.rs
new file mode 100644
index 0000000000..f840b8a9b2
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/01_quick.rs
@@ -0,0 +1,68 @@
+use std::path::PathBuf;
+
+use clap::{Parser, Subcommand};
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    /// Optional name to operate on
+    name: Option<String>,
+
+    /// Sets a custom config file
+    #[clap(short, long, parse(from_os_str), value_name = "FILE")]
+    config: Option<PathBuf>,
+
+    /// Turn debugging information on
+    #[clap(short, long, parse(from_occurrences))]
+    debug: usize,
+
+    #[clap(subcommand)]
+    command: Option<Commands>,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    /// does testing things
+    Test {
+        /// lists test values
+        #[clap(short, long)]
+        list: bool,
+    },
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    // You can check the value provided by positional arguments, or option arguments
+    if let Some(name) = cli.name.as_deref() {
+        println!("Value for name: {}", name);
+    }
+
+    if let Some(config_path) = cli.config.as_deref() {
+        println!("Value for config: {}", config_path.display());
+    }
+
+    // You can see how many times a particular flag or argument occurred
+    // Note, only flags can have multiple occurrences
+    match cli.debug {
+        0 => println!("Debug mode is off"),
+        1 => println!("Debug mode is kind of on"),
+        2 => println!("Debug mode is on"),
+        _ => println!("Don't be crazy"),
+    }
+
+    // You can check for the existence of subcommands, and if found use their
+    // matches just as you would the top level cmd
+    match &cli.command {
+        Some(Commands::Test { list }) => {
+            if *list {
+                println!("Printing testing lists...");
+            } else {
+                println!("Not printing testing lists...");
+            }
+        }
+        None => {}
+    }
+
+    // Continued program logic goes here...
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/02_app_settings.rs b/third_party/rust/clap/examples/tutorial_derive/02_app_settings.rs
new file mode 100644
index 0000000000..bccd353f60
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/02_app_settings.rs
@@ -0,0 +1,20 @@
+use clap::{AppSettings, Parser};
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+#[clap(args_override_self = true)]
+#[clap(allow_negative_numbers = true)]
+#[clap(global_setting(AppSettings::DeriveDisplayOrder))]
+struct Cli {
+    #[clap(long)]
+    two: String,
+    #[clap(long)]
+    one: String,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("two: {:?}", cli.two);
+    println!("one: {:?}", cli.one);
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/02_apps.rs b/third_party/rust/clap/examples/tutorial_derive/02_apps.rs
new file mode 100644
index 0000000000..442e928a9f
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/02_apps.rs
@@ -0,0 +1,20 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(name = "MyApp")]
+#[clap(author = "Kevin K. <kbknapp@gmail.com>")]
+#[clap(version = "1.0")]
+#[clap(about = "Does awesome things", long_about = None)]
+struct Cli {
+    #[clap(long)]
+    two: String,
+    #[clap(long)]
+    one: String,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("two: {:?}", cli.two);
+    println!("one: {:?}", cli.one);
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/02_crate.rs b/third_party/rust/clap/examples/tutorial_derive/02_crate.rs
new file mode 100644
index 0000000000..93f7888af3
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/02_crate.rs
@@ -0,0 +1,17 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    #[clap(long)]
+    two: String,
+    #[clap(long)]
+    one: String,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("two: {:?}", cli.two);
+    println!("one: {:?}", cli.one);
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/03_01_flag_bool.rs b/third_party/rust/clap/examples/tutorial_derive/03_01_flag_bool.rs
new file mode 100644
index 0000000000..8b574b7481
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/03_01_flag_bool.rs
@@ -0,0 +1,14 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    #[clap(short, long)]
+    verbose: bool,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("verbose: {:?}", cli.verbose);
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/03_01_flag_count.rs b/third_party/rust/clap/examples/tutorial_derive/03_01_flag_count.rs
new file mode 100644
index 0000000000..2ab883977a
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/03_01_flag_count.rs
@@ -0,0 +1,14 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    #[clap(short, long, parse(from_occurrences))]
+    verbose: usize,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("verbose: {:?}", cli.verbose);
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/03_02_option.rs b/third_party/rust/clap/examples/tutorial_derive/03_02_option.rs
new file mode 100644
index 0000000000..b09aadf20d
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/03_02_option.rs
@@ -0,0 +1,14 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    #[clap(short, long)]
+    name: Option<String>,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("name: {:?}", cli.name.as_deref());
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/03_03_positional.rs b/third_party/rust/clap/examples/tutorial_derive/03_03_positional.rs
new file mode 100644
index 0000000000..f7850ddccf
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/03_03_positional.rs
@@ -0,0 +1,13 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    name: Option<String>,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("name: {:?}", cli.name.as_deref());
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/03_04_subcommands.rs b/third_party/rust/clap/examples/tutorial_derive/03_04_subcommands.rs
new file mode 100644
index 0000000000..86cf444c21
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/03_04_subcommands.rs
@@ -0,0 +1,27 @@
+use clap::{Parser, Subcommand};
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+#[clap(propagate_version = true)]
+struct Cli {
+    #[clap(subcommand)]
+    command: Commands,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    /// Adds files to myapp
+    Add { name: Option<String> },
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    // You can check for the existence of subcommands, and if found use their
+    // matches just as you would the top level cmd
+    match &cli.command {
+        Commands::Add { name } => {
+            println!("'myapp add' was used, name is: {:?}", name)
+        }
+    }
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/03_04_subcommands_alt.rs b/third_party/rust/clap/examples/tutorial_derive/03_04_subcommands_alt.rs
new file mode 100644
index 0000000000..0a5b60682d
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/03_04_subcommands_alt.rs
@@ -0,0 +1,32 @@
+use clap::{Args, Parser, Subcommand};
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+#[clap(propagate_version = true)]
+struct Cli {
+    #[clap(subcommand)]
+    command: Commands,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    /// Adds files to myapp
+    Add(Add),
+}
+
+#[derive(Args)]
+struct Add {
+    name: Option<String>,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    // You can check for the existence of subcommands, and if found use their
+    // matches just as you would the top level cmd
+    match &cli.command {
+        Commands::Add(name) => {
+            println!("'myapp add' was used, name is: {:?}", name.name)
+        }
+    }
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/03_05_default_values.rs b/third_party/rust/clap/examples/tutorial_derive/03_05_default_values.rs
new file mode 100644
index 0000000000..af4532bbc7
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/03_05_default_values.rs
@@ -0,0 +1,14 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    #[clap(default_value_t = String::from("alice"))]
+    name: String,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("name: {:?}", cli.name);
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/04_01_enum.rs b/third_party/rust/clap/examples/tutorial_derive/04_01_enum.rs
new file mode 100644
index 0000000000..3a2df391ff
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/04_01_enum.rs
@@ -0,0 +1,28 @@
+use clap::{ArgEnum, Parser};
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    /// What mode to run the program in
+    #[clap(arg_enum)]
+    mode: Mode,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, ArgEnum)]
+enum Mode {
+    Fast,
+    Slow,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    match cli.mode {
+        Mode::Fast => {
+            println!("Hare");
+        }
+        Mode::Slow => {
+            println!("Tortoise");
+        }
+    }
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/04_02_parse.rs b/third_party/rust/clap/examples/tutorial_derive/04_02_parse.rs
new file mode 100644
index 0000000000..5f4cbadc04
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/04_02_parse.rs
@@ -0,0 +1,15 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    /// Network port to use
+    #[clap(parse(try_from_str))]
+    port: usize,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("PORT = {}", cli.port);
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/04_02_validate.rs b/third_party/rust/clap/examples/tutorial_derive/04_02_validate.rs
new file mode 100644
index 0000000000..434f40c869
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/04_02_validate.rs
@@ -0,0 +1,34 @@
+use std::ops::RangeInclusive;
+
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    /// Network port to use
+    #[clap(parse(try_from_str=port_in_range))]
+    port: usize,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("PORT = {}", cli.port);
+}
+
+const PORT_RANGE: RangeInclusive<usize> = 1..=65535;
+
+fn port_in_range(s: &str) -> Result<usize, String> {
+    let port: usize = s
+        .parse()
+        .map_err(|_| format!("`{}` isn't a port number", s))?;
+    if PORT_RANGE.contains(&port) {
+        Ok(port)
+    } else {
+        Err(format!(
+            "Port not in range {}-{}",
+            PORT_RANGE.start(),
+            PORT_RANGE.end()
+        ))
+    }
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/04_03_relations.rs b/third_party/rust/clap/examples/tutorial_derive/04_03_relations.rs
new file mode 100644
index 0000000000..f0e1e5913b
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/04_03_relations.rs
@@ -0,0 +1,72 @@
+use clap::{ArgGroup, Parser};
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+#[clap(group(
+            ArgGroup::new("vers")
+                .required(true)
+                .args(&["set-ver", "major", "minor", "patch"]),
+        ))]
+struct Cli {
+    /// set version manually
+    #[clap(long, value_name = "VER")]
+    set_ver: Option<String>,
+
+    /// auto inc major
+    #[clap(long)]
+    major: bool,
+
+    /// auto inc minor
+    #[clap(long)]
+    minor: bool,
+
+    /// auto inc patch
+    #[clap(long)]
+    patch: bool,
+
+    /// some regular input
+    #[clap(group = "input")]
+    input_file: Option<String>,
+
+    /// some special input argument
+    #[clap(long, group = "input")]
+    spec_in: Option<String>,
+
+    #[clap(short, requires = "input")]
+    config: Option<String>,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    // Let's assume the old version 1.2.3
+    let mut major = 1;
+    let mut minor = 2;
+    let mut patch = 3;
+
+    // See if --set-ver was used to set the version manually
+    let version = if let Some(ver) = cli.set_ver.as_deref() {
+        ver.to_string()
+    } else {
+        // Increment the one requested (in a real program, we'd reset the lower numbers)
+        let (maj, min, pat) = (cli.major, cli.minor, cli.patch);
+        match (maj, min, pat) {
+            (true, _, _) => major += 1,
+            (_, true, _) => minor += 1,
+            (_, _, true) => patch += 1,
+            _ => unreachable!(),
+        };
+        format!("{}.{}.{}", major, minor, patch)
+    };
+
+    println!("Version: {}", version);
+
+    // Check for usage of -c
+    if let Some(config) = cli.config.as_deref() {
+        let input = cli
+            .input_file
+            .as_deref()
+            .unwrap_or_else(|| cli.spec_in.as_deref().unwrap());
+        println!("Doing work using input {} and config {}", input, config);
+    }
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/04_04_custom.rs b/third_party/rust/clap/examples/tutorial_derive/04_04_custom.rs
new file mode 100644
index 0000000000..a03345b829
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/04_04_custom.rs
@@ -0,0 +1,92 @@
+use clap::{CommandFactory, ErrorKind, Parser};
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    /// set version manually
+    #[clap(long, value_name = "VER")]
+    set_ver: Option<String>,
+
+    /// auto inc major
+    #[clap(long)]
+    major: bool,
+
+    /// auto inc minor
+    #[clap(long)]
+    minor: bool,
+
+    /// auto inc patch
+    #[clap(long)]
+    patch: bool,
+
+    /// some regular input
+    input_file: Option<String>,
+
+    /// some special input argument
+    #[clap(long)]
+    spec_in: Option<String>,
+
+    #[clap(short)]
+    config: Option<String>,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    // Let's assume the old version 1.2.3
+    let mut major = 1;
+    let mut minor = 2;
+    let mut patch = 3;
+
+    // See if --set-ver was used to set the version manually
+    let version = if let Some(ver) = cli.set_ver.as_deref() {
+        if cli.major || cli.minor || cli.patch {
+            let mut cmd = Cli::command();
+            cmd.error(
+                ErrorKind::ArgumentConflict,
+                "Can't do relative and absolute version change",
+            )
+            .exit();
+        }
+        ver.to_string()
+    } else {
+        // Increment the one requested (in a real program, we'd reset the lower numbers)
+        let (maj, min, pat) = (cli.major, cli.minor, cli.patch);
+        match (maj, min, pat) {
+            (true, false, false) => major += 1,
+            (false, true, false) => minor += 1,
+            (false, false, true) => patch += 1,
+            _ => {
+                let mut cmd = Cli::command();
+                cmd.error(
+                    ErrorKind::ArgumentConflict,
+                    "Can only modify one version field",
+                )
+                .exit();
+            }
+        };
+        format!("{}.{}.{}", major, minor, patch)
+    };
+
+    println!("Version: {}", version);
+
+    // Check for usage of -c
+    if let Some(config) = cli.config.as_deref() {
+        // todo: remove `#[allow(clippy::or_fun_call)]` lint when MSRV is bumped.
+        #[allow(clippy::or_fun_call)]
+        let input = cli
+            .input_file
+            .as_deref()
+            // 'or' is preferred to 'or_else' here since `Option::as_deref` is 'const'
+            .or(cli.spec_in.as_deref())
+            .unwrap_or_else(|| {
+                let mut cmd = Cli::command();
+                cmd.error(
+                    ErrorKind::MissingRequiredArgument,
+                    "INPUT_FILE or --spec-in is required when using --config",
+                )
+                .exit()
+            });
+        println!("Doing work using input {} and config {}", input, config);
+    }
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/05_01_assert.rs b/third_party/rust/clap/examples/tutorial_derive/05_01_assert.rs
new file mode 100644
index 0000000000..12fdba9b92
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/05_01_assert.rs
@@ -0,0 +1,21 @@
+use clap::Parser;
+
+#[derive(Parser)]
+#[clap(author, version, about, long_about = None)]
+struct Cli {
+    /// Network port to use
+    #[clap(parse(try_from_str))]
+    port: usize,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("PORT = {}", cli.port);
+}
+
+#[test]
+fn verify_app() {
+    use clap::CommandFactory;
+    Cli::command().debug_assert()
+}
diff --git a/third_party/rust/clap/examples/tutorial_derive/README.md b/third_party/rust/clap/examples/tutorial_derive/README.md
new file mode 100644
index 0000000000..706e76c09e
--- /dev/null
+++ b/third_party/rust/clap/examples/tutorial_derive/README.md
@@ -0,0 +1,642 @@
+# Tutorial
+
+*Jump to [builder tutorial](../tutorial_builder/README.md)*
+
+1. [Quick Start](#quick-start)
+2. [Configuring the Parser](#configuring-the-parser)
+3. [Adding Arguments](#adding-arguments)
+    1. [Positionals](#positionals)
+    2. [Options](#options)
+    3. [Flags](#flags)
+    4. [Subcommands](#subcommands)
+    5. [Defaults](#defaults)
+4. Validation
+    1. [Enumerated values](#enumerated-values)
+    2. [Validated values](#validated-values)
+    3. [Argument Relations](#argument-relations)
+    4. [Custom Validation](#custom-validation)
+5. [Tips](#tips)
+6. [Contributing](#contributing)
+
+## Quick Start
+
+You can create an application declaratively with a `struct` and some
+attributes.  **This requires enabling the `derive` feature flag.**
+
+[Example:](01_quick.rs)
+```console
+$ 01_quick_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    01_quick_derive[EXE] [OPTIONS] [NAME] [SUBCOMMAND]
+
+ARGS:
+    <NAME>    Optional name to operate on
+
+OPTIONS:
+    -c, --config <FILE>    Sets a custom config file
+    -d, --debug            Turn debugging information on
+    -h, --help             Print help information
+    -V, --version          Print version information
+
+SUBCOMMANDS:
+    help    Print this message or the help of the given subcommand(s)
+    test    does testing things
+
+```
+
+By default, the program does nothing:
+```console
+$ 01_quick_derive
+Debug mode is off
+
+```
+
+But you can mix and match the various features
+```console
+$ 01_quick_derive -dd test
+Debug mode is on
+Not printing testing lists...
+
+```
+
+In addition to this tutorial, see the [derive reference](../derive_ref/README.md).
+
+## Configuring the Parser
+
+You use derive `Parser` the start building a parser.
+
+[Example:](02_apps.rs)
+```console
+$ 02_apps_derive --help
+MyApp 1.0
+Kevin K. <kbknapp@gmail.com>
+Does awesome things
+
+USAGE:
+    02_apps_derive[EXE] --two <TWO> --one <ONE>
+
+OPTIONS:
+    -h, --help         Print help information
+        --one <ONE>    
+        --two <TWO>    
+    -V, --version      Print version information
+
+$ 02_apps_derive --version
+MyApp 1.0
+
+```
+
+You can use `#[clap(author, version, about)]` attribute defaults to fill these fields in from your `Cargo.toml` file.
+
+[Example:](02_crate.rs)
+```console
+$ 02_crate_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    02_crate_derive[EXE] --two <TWO> --one <ONE>
+
+OPTIONS:
+    -h, --help         Print help information
+        --one <ONE>    
+        --two <TWO>    
+    -V, --version      Print version information
+
+$ 02_crate_derive --version
+clap [..]
+
+```
+
+You can use attributes to change the application level behavior of clap.  Any `Command` builder function can be used as an attribute.
+
+[Example:](02_app_settings.rs)
+```console
+$ 02_app_settings_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    02_app_settings_derive[EXE] --two <TWO> --one <ONE>
+
+OPTIONS:
+        --two <TWO>    
+        --one <ONE>    
+    -h, --help         Print help information
+    -V, --version      Print version information
+
+$ 02_app_settings_derive --one -1 --one -3 --two 10
+two: "10"
+one: "-3"
+
+```
+
+## Adding Arguments
+
+### Positionals
+
+You can have users specify values by their position on the command-line:
+
+[Example:](03_03_positional.rs)
+```console
+$ 03_03_positional_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    03_03_positional_derive[EXE] [NAME]
+
+ARGS:
+    <NAME>    
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+$ 03_03_positional_derive
+name: None
+
+$ 03_03_positional_derive bob
+name: Some("bob")
+
+```
+
+### Options
+
+You can name your arguments with a flag:
+- Order doesn't matter
+- They can be optional
+- Intent is clearer
+
+The `#[clap(short = 'c')]` and `#[clap(long = "name")]` attributes that define
+the flags are `Arg` methods that are derived from the field name when no value
+is specified (`#[clap(short)]` and `#[clap(long)]`).
+
+[Example:](03_02_option.rs)
+```console
+$ 03_02_option_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    03_02_option_derive[EXE] [OPTIONS]
+
+OPTIONS:
+    -h, --help           Print help information
+    -n, --name <NAME>    
+    -V, --version        Print version information
+
+$ 03_02_option_derive
+name: None
+
+$ 03_02_option_derive --name bob
+name: Some("bob")
+
+$ 03_02_option_derive --name=bob
+name: Some("bob")
+
+$ 03_02_option_derive -n bob
+name: Some("bob")
+
+$ 03_02_option_derive -n=bob
+name: Some("bob")
+
+$ 03_02_option_derive -nbob
+name: Some("bob")
+
+```
+
+### Flags
+
+Flags can also be switches that can be on/off.  This is enabled via the
+`#[clap(parse(from_flag)]` attribute though this is implied when the field is a
+`bool`.
+
+[Example:](03_01_flag_bool.rs)
+```console
+$ 03_01_flag_bool_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    03_01_flag_bool_derive[EXE] [OPTIONS]
+
+OPTIONS:
+    -h, --help       Print help information
+    -v, --verbose    
+    -V, --version    Print version information
+
+$ 03_01_flag_bool_derive
+verbose: false
+
+$ 03_01_flag_bool_derive --verbose
+verbose: true
+
+$ 03_01_flag_bool_derive --verbose --verbose
+? failed
+error: The argument '--verbose' was provided more than once, but cannot be used multiple times
+
+USAGE:
+    03_01_flag_bool_derive[EXE] [OPTIONS]
+
+For more information try --help
+
+```
+
+Or counted with `#[clap(parse(from_occurrences))]`:
+
+[Example:](03_01_flag_count.rs)
+```console
+$ 03_01_flag_count_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    03_01_flag_count_derive[EXE] [OPTIONS]
+
+OPTIONS:
+    -h, --help       Print help information
+    -v, --verbose    
+    -V, --version    Print version information
+
+$ 03_01_flag_count_derive
+verbose: 0
+
+$ 03_01_flag_count_derive --verbose
+verbose: 1
+
+$ 03_01_flag_count_derive --verbose --verbose
+verbose: 2
+
+```
+
+### Subcommands
+
+Subcommands are derived with `#[derive(Subcommand)]` and be added via `#[clap(subcommand)]` attribute. Each
+instance of a Subcommand can have its own version, author(s), Args, and even its own
+subcommands.
+
+[Example:](03_04_subcommands.rs)
+```console
+$ 03_04_subcommands_derive help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    03_04_subcommands_derive[EXE] <SUBCOMMAND>
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+SUBCOMMANDS:
+    add     Adds files to myapp
+    help    Print this message or the help of the given subcommand(s)
+
+$ 03_04_subcommands_derive help add
+03_04_subcommands_derive[EXE]-add [..]
+Adds files to myapp
+
+USAGE:
+    03_04_subcommands_derive[EXE] add [NAME]
+
+ARGS:
+    <NAME>    
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+$ 03_04_subcommands_derive add bob
+'myapp add' was used, name is: Some("bob")
+
+```
+
+Above, we used a struct-variant to define the `add` subcommand.  Alternatively,
+you can
+[use a struct for your subcommand's arguments](03_04_subcommands_alt.rs).
+
+Because we used `command: Commands` instead of `command: Option<Commands>`:
+```console
+$ 03_04_subcommands_derive
+? failed
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    03_04_subcommands_derive[EXE] <SUBCOMMAND>
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+SUBCOMMANDS:
+    add     Adds files to myapp
+    help    Print this message or the help of the given subcommand(s)
+
+```
+
+Because we added `#[clap(propagate_version = true)]`:
+```console
+$ 03_04_subcommands_derive --version
+clap [..]
+
+$ 03_04_subcommands_derive add --version
+03_04_subcommands_derive[EXE]-add [..]
+
+```
+
+### Defaults
+
+We've previously showed that arguments can be `required` or optional.  When
+optional, you work with an `Option` and can `unwrap_or`.  Alternatively, you can
+set `#[clap(default_value_t)]`.
+
+[Example:](03_05_default_values.rs)
+```console
+$ 03_05_default_values_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    03_05_default_values_derive[EXE] [NAME]
+
+ARGS:
+    <NAME>    [default: alice]
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+$ 03_05_default_values_derive
+name: "alice"
+
+$ 03_05_default_values_derive bob
+name: "bob"
+
+```
+
+## Validation
+
+### Enumerated values
+
+If you have arguments of specific values you want to test for, you can derive
+`ArgEnum`.
+
+This allows you specify the valid values for that argument. If the user does not use one of
+those specific values, they will receive a graceful exit with error message informing them
+of the mistake, and what the possible valid values are
+
+[Example:](04_01_enum.rs)
+```console
+$ 04_01_enum_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    04_01_enum_derive[EXE] <MODE>
+
+ARGS:
+    <MODE>    What mode to run the program in [possible values: fast, slow]
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+$ 04_01_enum_derive fast
+Hare
+
+$ 04_01_enum_derive slow
+Tortoise
+
+$ 04_01_enum_derive medium
+? failed
+error: "medium" isn't a valid value for '<MODE>'
+	[possible values: fast, slow]
+
+USAGE:
+    04_01_enum_derive[EXE] <MODE>
+
+For more information try --help
+
+```
+
+### Validated values
+
+More generally, you can validate and parse into any data type.
+
+[Example:](04_02_parse.rs)
+```console
+$ 04_02_parse_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    04_02_parse_derive[EXE] <PORT>
+
+ARGS:
+    <PORT>    Network port to use
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+$ 04_02_parse_derive 22
+PORT = 22
+
+$ 04_02_parse_derive foobar
+? failed
+error: Invalid value "foobar" for '<PORT>': invalid digit found in string
+
+For more information try --help
+
+```
+
+A custom parser can be used to improve the error messages or provide additional validation:
+
+[Example:](04_02_validate.rs)
+```console
+$ 04_02_validate_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    04_02_validate_derive[EXE] <PORT>
+
+ARGS:
+    <PORT>    Network port to use
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+$ 04_02_validate_derive 22
+PORT = 22
+
+$ 04_02_validate_derive foobar
+? failed
+error: Invalid value "foobar" for '<PORT>': `foobar` isn't a port number
+
+For more information try --help
+
+$ 04_02_validate_derive 0
+? failed
+error: Invalid value "0" for '<PORT>': Port not in range 1-65535
+
+For more information try --help
+
+```
+
+### Argument Relations
+
+You can declare dependencies or conflicts between `Arg`s or even `ArgGroup`s.  
+
+`ArgGroup`s  make it easier to declare relations instead of having to list each
+individually, or when you want a rule to apply "any but not all" arguments.
+
+Perhaps the most common use of `ArgGroup`s is to require one and *only* one argument to be
+present out of a given set. Imagine that you had multiple arguments, and you want one of them to
+be required, but making all of them required isn't feasible because perhaps they conflict with
+each other.
+
+[Example:](04_03_relations.rs)
+```console
+$ 04_03_relations_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    04_03_relations_derive[EXE] [OPTIONS] <--set-ver <VER>|--major|--minor|--patch> [INPUT_FILE]
+
+ARGS:
+    <INPUT_FILE>    some regular input
+
+OPTIONS:
+    -c <CONFIG>                
+    -h, --help                 Print help information
+        --major                auto inc major
+        --minor                auto inc minor
+        --patch                auto inc patch
+        --set-ver <VER>        set version manually
+        --spec-in <SPEC_IN>    some special input argument
+    -V, --version              Print version information
+
+$ 04_03_relations_derive
+? failed
+error: The following required arguments were not provided:
+    <--set-ver <VER>|--major|--minor|--patch>
+
+USAGE:
+    04_03_relations_derive[EXE] [OPTIONS] <--set-ver <VER>|--major|--minor|--patch> [INPUT_FILE]
+
+For more information try --help
+
+$ 04_03_relations_derive --major
+Version: 2.2.3
+
+$ 04_03_relations_derive --major --minor
+? failed
+error: The argument '--major' cannot be used with '--minor'
+
+USAGE:
+    04_03_relations_derive[EXE] <--set-ver <VER>|--major|--minor|--patch>
+
+For more information try --help
+
+$ 04_03_relations_derive --major -c config.toml
+? failed
+error: The following required arguments were not provided:
+    <INPUT_FILE|--spec-in <SPEC_IN>>
+
+USAGE:
+    04_03_relations_derive[EXE] -c <CONFIG> <--set-ver <VER>|--major|--minor|--patch> <INPUT_FILE|--spec-in <SPEC_IN>>
+
+For more information try --help
+
+$ 04_03_relations_derive --major -c config.toml --spec-in input.txt
+Version: 2.2.3
+Doing work using input input.txt and config config.toml
+
+```
+
+### Custom Validation
+
+As a last resort, you can create custom errors with the basics of clap's formatting.
+
+[Example:](04_04_custom.rs)
+```console
+$ 04_04_custom_derive --help
+clap [..]
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    04_04_custom_derive[EXE] [OPTIONS] [INPUT_FILE]
+
+ARGS:
+    <INPUT_FILE>    some regular input
+
+OPTIONS:
+    -c <CONFIG>                
+    -h, --help                 Print help information
+        --major                auto inc major
+        --minor                auto inc minor
+        --patch                auto inc patch
+        --set-ver <VER>        set version manually
+        --spec-in <SPEC_IN>    some special input argument
+    -V, --version              Print version information
+
+$ 04_04_custom_derive
+? failed
+error: Can only modify one version field
+
+USAGE:
+    clap [OPTIONS] [INPUT_FILE]
+
+For more information try --help
+
+$ 04_04_custom_derive --major
+Version: 2.2.3
+
+$ 04_04_custom_derive --major --minor
+? failed
+error: Can only modify one version field
+
+USAGE:
+    clap [OPTIONS] [INPUT_FILE]
+
+For more information try --help
+
+$ 04_04_custom_derive --major -c config.toml
+? failed
+Version: 2.2.3
+error: INPUT_FILE or --spec-in is required when using --config
+
+USAGE:
+    clap [OPTIONS] [INPUT_FILE]
+
+For more information try --help
+
+$ 04_04_custom_derive --major -c config.toml --spec-in input.txt
+Version: 2.2.3
+Doing work using input input.txt and config config.toml
+
+```
+
+## Tips
+
+- For more complex demonstration of features, see our [examples](../README.md).
+- See the [derive reference](../derive_ref/README.md) to understand how to use
+  anything in the [builder API](https://docs.rs/clap/) in the derive API.
+- Proactively check for bad `Command` configurations by calling `Command::debug_assert` in a test ([example](05_01_assert.rs))
+
+## Contributing
+
+New example code:
+- Please update the corresponding section in the [builder tutorial](../tutorial_builder/README.md)
+- Building: They must be added to [Cargo.toml](../../Cargo.toml) with the appropriate `required-features`.
+- Testing: Ensure there is a markdown file with [trycmd](https://docs.rs/trycmd) syntax (generally they'll go in here).
+
+See also the general [CONTRIBUTING](../../CONTRIBUTING.md).