Fix #168

CHANGELOG.md

@@ -1,3 +1,7 @@
+# v0.2.15 (2018-03-08)
+
+* Fix [#168](https://github.com/TeXitoi/structopt/issues/168) by [@TeXitoi](https://github.com/TeXitoi)
+
 # v0.2.14 (2018-12-10)
 
 * Introduce smarter parsing of doc comments by [@0ndorio](https://github.com/0ndorio)

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "structopt"
-version = "0.2.14"
+version = "0.2.15"
 authors = ["Guillaume Pinot <[email protected]>", "others"]
 description = "Parse command line argument by defining a struct."
 documentation = "https://docs.rs/structopt"
@@ -27,6 +27,6 @@ travis-ci = { repository = "TeXitoi/structopt" }
 
 [dependencies]
 clap = { version = "2.21", default-features = false }
-structopt-derive = { path = "structopt-derive", version = "0.2.14" }
+structopt-derive = { path = "structopt-derive", version = "0.2.15" }
 
 [workspace]

examples/doc_comments.rs

@@ -9,7 +9,6 @@
 #[macro_use]
 extern crate structopt;
 
-use std::path::PathBuf;
 use structopt::StructOpt;
 
 /// A basic example for the usage of doc comments as replacement

structopt-derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "structopt-derive"
-version = "0.2.14"
+version = "0.2.15"
 authors = ["Guillaume Pinot <[email protected]>"]
 description = "Parse command line argument by defining a struct, derive crate."
 documentation = "https://docs.rs/structopt-derive"

structopt-derive/src/lib.rs

@@ -220,7 +220,6 @@ fn gen_constructor(fields: &Punctuated<Field, Comma>, parent_attribute: &Attrs)
                     Ty::Bool => quote!(matches.is_present(#name)),
                     Ty::Option => quote! {
                         matches.#value_of(#name)
-                            .as_ref()
                             .map(#parse)
                     },
                     Ty::Vec => quote! {

tests/options.rs

@@ -130,3 +130,24 @@ fn empy_default_value() {
         Opt::from_iter(&["test", "-afoo"])
     );
 }
+
+#[test]
+fn option_from_str() {
+    #[derive(Debug, PartialEq)]
+    struct A;
+
+    impl<'a> From<&'a str> for A {
+        fn from(_: &str) -> A {
+            A
+        }
+    }
+
+    #[derive(Debug, StructOpt, PartialEq)]
+    struct Opt {
+        #[structopt(parse(from_str))]
+        a: Option<A>,
+    }
+
+    assert_eq!(Opt { a: None }, Opt::from_iter(&["test"]));
+    assert_eq!(Opt { a: Some(A) }, Opt::from_iter(&["test", "foo"]));
+}