Add structopt dependency in version 0.3.7

This patch series replaces argparse with structopt in the argument
handling code. As a first step, we need structopt as a dependency.

Import subrepo structopt/:structopt at efbdda4753592e27bc430fb01f7b9650b2f3174d
Import subrepo bitflags/:bitflags at 30668016aca6bd3b02c766e8347e0b4080d4c296
Import subrepo clap/:clap at 784524f7eb193e35f81082cc69454c8c21b948f7
Import subrepo heck/:heck at 093d56fbf001e1506e56dbfa38631d99b1066df1
Import subrepo proc-macro-error/:proc-macro-error at 6c4cfe79a622c5de8ae68557993542be46eacae2
Import subrepo proc-macro2/:proc-macro2 at d5d48eddca4566e5438e8a2cbed4a74e049544de
Import subrepo quote/:quote at 727436c6c137b20f0f34dde5d8fda2679b9747ad
Import subrepo rustversion/:rustversion at 0c5663313516263059ce9059ef81fc7a1cf655ca
Import subrepo syn-mid/:syn-mid at 5d3d85414a9e6674e1857ec22a87b96e04a6851a
Import subrepo syn/:syn at e87c27e87f6f4ef8919d0372bdb056d53ef0d8f3
Import subrepo textwrap/:textwrap at abcd618beae3f74841032aa5b53c1086b0a57ca2
Import subrepo unicode-segmentation/:unicode-segmentation at 637c9874c4fe0c205ff27787faf150a40295c6c3
Import subrepo unicode-width/:unicode-width at 3033826f8bf05e82724140a981d5941e48fce393
Import subrepo unicode-xid/:unicode-xid at 4baae9fffb156ba229665b972a9cd5991787ceb7

1 files changed, 68 insertions, 0 deletions

diff --git a/clap/examples/13a_enum_values_automatic.rs b/clap/examples/13a_enum_values_automatic.rs
new file mode 100644
index 0000000..1abe5cb
--- /dev/null
+++ b/clap/examples/13a_enum_values_automatic.rs
@@ -0,0 +1,68 @@
+// You can use clap's value_t! macro with a custom enum by implementing the std::str::FromStr
+// trait which is very straight forward. There are three ways to do this, for simple enums
+// meaning those that don't require 'pub' or any '#[derive()]' directives you can use clap's
+// simple_enum! macro. For those that require 'pub' or any '#[derive()]'s you can use clap's
+// arg_enum! macro. The third way is to implement std::str::FromStr manually.
+//
+// In most circumstances using either simple_enum! or arg_enum! is fine.
+//
+// In the following example we will create two enums using macros, assign a positional argument
+// that accepts only one of those values, and use clap to parse the argument.
+
+// Add clap like normal
+#[macro_use]
+extern crate clap;
+
+use clap::{App, Arg};
+
+// Using arg_enum! is more like traditional enum declarations
+//
+// **NOTE:** Only bare variants are supported
+arg_enum!{
+    #[derive(Debug)]
+    pub enum Oof {
+        Rab,
+        Zab,
+        Xuq
+    }
+}
+
+arg_enum!{
+    #[derive(Debug)]
+    enum Foo {
+        Bar,
+        Baz,
+        Qux
+    }
+}
+
+fn main() {
+    // Create the application like normal
+    let enum_vals = ["fast", "slow"];
+    let m = App::new("myapp")
+                    // Use a single positional argument that is required
+                    .arg(Arg::from_usage("<foo> 'The Foo to use'")
+                        .possible_values(&Foo::variants()))
+                    .arg(Arg::from_usage("<speed> 'The speed to use'")
+                            // You can define a list of possible values if you want the values to be
+                            // displayed in the help information. Whether you use possible_values() or
+                            // not, the valid values will ALWAYS be displayed on a failed parse.
+                            .possible_values(&enum_vals))
+                    // For the second positional, lets not use possible_values() just to show the difference
+                    .arg_from_usage("<oof> 'The Oof to use'")
+                    .get_matches();
+
+    let t = value_t!(m.value_of("foo"), Foo).unwrap_or_else(|e| e.exit());
+    let t2 = value_t!(m.value_of("oof"), Oof).unwrap_or_else(|e| e.exit());
+
+
+    // Now we can use our enum like normal.
+    match t {
+        Foo::Bar => println!("Found a Bar"),
+        Foo::Baz => println!("Found a Baz"),
+        Foo::Qux => println!("Found a Qux")
+    }
+
+    // Since our Oof derives Debug, we can do this:
+    println!("Oof: {:?}", t2);
+}