From fe38226bf4d882e7295f926f2099bd3520739e81 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Mon, 10 Apr 2017 11:47:28 -0700
Subject: [PATCH 01/16] Added attribute and hooks in derive_builder

---
 derive_builder/Cargo.toml                   |  1 +
 derive_builder/src/options/field_mode.rs    |  2 ++
 derive_builder/src/options/field_options.rs |  2 ++
 derive_builder/src/options/mod.rs           | 11 +++++++++++
 derive_builder/src/options/struct_mode.rs   |  1 +
 derive_builder/tests/try_setter.rs          | 18 ++++++++++++++++++
 6 files changed, 35 insertions(+)
 create mode 100644 derive_builder/tests/try_setter.rs

diff --git a/derive_builder/Cargo.toml b/derive_builder/Cargo.toml
index 962b2771..4bf760ee 100644
--- a/derive_builder/Cargo.toml
+++ b/derive_builder/Cargo.toml
@@ -25,6 +25,7 @@ proc-macro = true
 logging = [ "log", "env_logger", "derive_builder_core/logging" ]
 struct_default = []
 skeptic_tests = ["skeptic"]
+try_setter = []
 
 [dependencies]
 syn = "0.11"
diff --git a/derive_builder/src/options/field_mode.rs b/derive_builder/src/options/field_mode.rs
index 06159ed1..da012d4c 100644
--- a/derive_builder/src/options/field_mode.rs
+++ b/derive_builder/src/options/field_mode.rs
@@ -81,6 +81,7 @@ impl OptionsBuilder<FieldMode> {
             setter_vis: f!(setter_vis),
             default_expression: f!(default_expression),
             setter_into: f!(setter_into),
+            try_setter_enabled: f!(try_setter_enabled),
             no_std: f!(no_std),
             mode: mode,
         }
@@ -133,6 +134,7 @@ impl From<OptionsBuilder<FieldMode>> for FieldOptions {
             field_ident: field_ident,
             field_type: field_type,
             setter_into: b.setter_into.unwrap_or(false),
+            try_setter_enabled: b.try_setter_enabled.unwrap_or(false),
             deprecation_notes: b.mode.deprecation_notes.clone(),
             default_expression: b.default_expression.clone(),
             use_default_struct: b.mode.use_default_struct,
diff --git a/derive_builder/src/options/field_options.rs b/derive_builder/src/options/field_options.rs
index a17d1977..0ce7f54b 100644
--- a/derive_builder/src/options/field_options.rs
+++ b/derive_builder/src/options/field_options.rs
@@ -31,6 +31,8 @@ pub struct FieldOptions {
     pub attrs: Vec<syn::Attribute>,
     /// Bindings to libstd or libcore.
     pub bindings: Bindings,
+    /// Enables code generation for the TryInto setter.
+    pub try_setter_enabled: bool,
 }
 
 impl DefaultExpression {
diff --git a/derive_builder/src/options/mod.rs b/derive_builder/src/options/mod.rs
index e2b43a6c..6b8ed902 100644
--- a/derive_builder/src/options/mod.rs
+++ b/derive_builder/src/options/mod.rs
@@ -45,6 +45,7 @@ pub struct OptionsBuilder<Mode> {
     setter_vis: Option<syn::Visibility>,
     default_expression: Option<DefaultExpression>,
     setter_into: Option<bool>,
+    try_setter_enabled: Option<bool>,
     no_std: Option<bool>,
     mode: Mode,
 }
@@ -66,6 +67,7 @@ impl<Mode> From<Mode> for OptionsBuilder<Mode> {
             setter_prefix: None,
             setter_name: None,
             setter_vis: None,
+            try_setter_enabled: None,
             default_expression: None,
             setter_into: None,
             no_std: None,
@@ -100,6 +102,12 @@ impl<Mode> OptionsBuilder<Mode> where
         desc: "setter type conversion",
         map: |x: bool| { x },
     }
+    
+    impl_setter!{
+        ident: try_setter_enabled,
+        desc: "try_setter activation",
+        map: |x: bool| { x },
+    }
 
     impl_setter!{
         ident: default_expression,
@@ -198,6 +206,9 @@ impl<Mode> OptionsBuilder<Mode> where
                 // setter implicitly enabled
                 self.setter_enabled(true)
             },
+            "try_setter" => {
+                self.try_setter_enabled(true)
+            }
             "default" => {
                 if !cfg!(feature = "struct_default") && self.mode.struct_mode() {
                     let where_info = self.where_diagnostics();
diff --git a/derive_builder/src/options/struct_mode.rs b/derive_builder/src/options/struct_mode.rs
index a43e7d49..0c082f97 100644
--- a/derive_builder/src/options/struct_mode.rs
+++ b/derive_builder/src/options/struct_mode.rs
@@ -78,6 +78,7 @@ impl From<OptionsBuilder<StructMode>> for (StructOptions, OptionsBuilder<FieldMo
             setter_prefix: b.setter_prefix,
             setter_vis: b.setter_vis,
             setter_into: b.setter_into,
+            try_setter_enabled: b.try_setter_enabled,
             default_expression: field_default_expression,
             no_std: b.no_std,
             mode: {
diff --git a/derive_builder/tests/try_setter.rs b/derive_builder/tests/try_setter.rs
new file mode 100644
index 00000000..5eb232a7
--- /dev/null
+++ b/derive_builder/tests/try_setter.rs
@@ -0,0 +1,18 @@
+#[macro_use]
+extern crate derive_builder;
+
+mod struct_level {
+    use std::net::SocketAddr;
+    use std::str::FromStr;
+    
+    #[derive(Debug, Builder)]
+    #[builder(try_setter, setter(into))]
+    struct Lorem {
+        pub address: SocketAddr
+    }
+    
+    #[test]
+    fn infallible_set() {
+        let _ = LoremBuilder::default().address(SocketAddr::from_str("1.2.3.4:80").unwrap()).build();
+    }
+}
\ No newline at end of file

From f0772dfc137096f21286c0bf82125d1f8495afb9 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Mon, 10 Apr 2017 12:48:35 -0700
Subject: [PATCH 02/16] Happy path works.

NOT YET DONE
* Generate appropriate documentation for `try_` methods
* Confirm core::convert::TryInto exists
* Finalize declaration (`try_setter` vs. `setter(include_try)`

CAVEATS
* An error on a try_ with the owned builder pattern is irrecoverable because the builder was consumed and not returned
* Without error_chain or the like, error handling can be verbose
---
 derive_builder/src/options/field_options.rs |  1 +
 derive_builder/tests/try_setter.rs          | 64 +++++++++++++++++++--
 derive_builder_core/src/bindings.rs         |  9 +++
 derive_builder_core/src/setter.rs           | 26 ++++++++-
 4 files changed, 93 insertions(+), 7 deletions(-)

diff --git a/derive_builder/src/options/field_options.rs b/derive_builder/src/options/field_options.rs
index 0ce7f54b..521d9788 100644
--- a/derive_builder/src/options/field_options.rs
+++ b/derive_builder/src/options/field_options.rs
@@ -60,6 +60,7 @@ impl FieldOptions {
     pub fn as_setter<'a>(&'a self) -> Setter<'a> {
         Setter {
             enabled: self.setter_enabled,
+            try_enabled: self.try_setter_enabled,
             visibility: &self.setter_visibility,
             pattern: self.builder_pattern,
             attrs: &self.attrs,
diff --git a/derive_builder/tests/try_setter.rs b/derive_builder/tests/try_setter.rs
index 5eb232a7..93d3a560 100644
--- a/derive_builder/tests/try_setter.rs
+++ b/derive_builder/tests/try_setter.rs
@@ -1,18 +1,70 @@
+#![feature(try_from)]
+
 #[macro_use]
 extern crate derive_builder;
 
 mod struct_level {
-    use std::net::SocketAddr;
+    use std::convert::TryFrom;
+    use std::net::{IpAddr, AddrParseError};
     use std::str::FromStr;
-    
-    #[derive(Debug, Builder)]
+    use std::string::ToString;
+
+    #[derive(Debug, Clone, PartialEq)]
+    pub struct MyAddr(IpAddr);
+
+    impl From<IpAddr> for MyAddr {
+        fn from(v: IpAddr) -> Self {
+            MyAddr(v)
+        }
+    }
+
+    impl<'a> TryFrom<&'a str> for MyAddr {
+        type Err = AddrParseError;
+
+        fn try_from(v: &str) -> Result<Self, Self::Err> {
+            Ok(MyAddr(v.parse()?))
+        }
+    }
+
+    #[derive(Debug, PartialEq, Builder)]
     #[builder(try_setter, setter(into))]
     struct Lorem {
-        pub address: SocketAddr
+        pub source: MyAddr,
+        pub dest: MyAddr,
     }
-    
+
     #[test]
     fn infallible_set() {
-        let _ = LoremBuilder::default().address(SocketAddr::from_str("1.2.3.4:80").unwrap()).build();
+        let _ = LoremBuilder::default().source(IpAddr::from_str("1.2.3.4").unwrap()).build();
+    }
+
+    #[test]
+    fn fallible_set() {
+        let mut builder = LoremBuilder::default();
+        let try_result = builder.try_source("1.2.3.4");
+        let built = try_result.expect("Passed well-formed address")
+            .dest(IpAddr::from_str("0.0.0.0").unwrap())
+            .build()
+            .unwrap();
+        assert_eq!(built, exact_helper().unwrap());
+    }
+
+    fn exact_helper() -> Result<Lorem, String> {
+        LoremBuilder::default()
+            .source(IpAddr::from_str("1.2.3.4").unwrap())
+            .dest(IpAddr::from_str("0.0.0.0").unwrap())
+            .build()
+    }
+
+    fn try_helper() -> Result<Lorem, String> {
+        LoremBuilder::default()
+            .try_source("1.2.3.4").map_err(|e| e.to_string())?
+            .try_dest("0.0.0.0").map_err(|e| e.to_string())?
+            .build()
+    }
+
+    #[test]
+    fn with_helper() {
+        assert_eq!(exact_helper().unwrap(), try_helper().unwrap());
     }
 }
\ No newline at end of file
diff --git a/derive_builder_core/src/bindings.rs b/derive_builder_core/src/bindings.rs
index 099c1bc1..6edb3fa1 100644
--- a/derive_builder_core/src/bindings.rs
+++ b/derive_builder_core/src/bindings.rs
@@ -70,6 +70,15 @@ impl Bindings {
             ":: std :: convert :: Into"
         })
     }
+    
+    /// TryInto trait.
+    pub fn try_into_trait(&self) -> RawTokens<&'static str> {
+        RawTokens(if self.no_std {
+            ":: core :: convert :: TryInto"
+        } else {
+            ":: std :: convert :: TryInto"
+        })
+    }
 }
 
 #[test]
diff --git a/derive_builder_core/src/setter.rs b/derive_builder_core/src/setter.rs
index cfcc8908..61db6aee 100644
--- a/derive_builder_core/src/setter.rs
+++ b/derive_builder_core/src/setter.rs
@@ -34,6 +34,8 @@ use Bindings;
 pub struct Setter<'a> {
     /// Enables code generation for this setter fn.
     pub enabled: bool,
+    /// Enables code generation for the `try_` variant of this setter fn.
+    pub try_enabled: bool,
     /// Visibility of the setter, e.g. `syn::Visibility::Public`.
     pub visibility: &'a syn::Visibility,
     /// How the setter method takes and returns `self` (e.g. mutably).
@@ -58,7 +60,7 @@ pub struct Setter<'a> {
 
 impl<'a> ToTokens for Setter<'a> {
     fn to_tokens(&self, tokens: &mut Tokens) {
-        if self.enabled {
+        if self.enabled || self.try_enabled {
             trace!("Deriving setter for `{}`.", self.field_ident);
             let ty = self.field_type;
             let pattern = self.pattern;
@@ -117,6 +119,27 @@ impl<'a> ToTokens for Setter<'a> {
                     new.#field_ident = #option::Some(#into_value);
                     new
             }));
+            
+            if self.try_enabled {
+                let try_into = self.bindings.try_into_trait();
+                let try_ty_params = quote!(<VALUE: #try_into<#ty>>);
+                let try_ident = syn::Ident::new(format!("try_{}", ident));
+                let result = self.bindings.result_ty();
+                
+                tokens.append(quote!(
+                    #(#attrs)*
+                    #vis fn #try_ident #try_ty_params (#self_param, value: VALUE)
+                        -> #result<#return_ty, VALUE::Err>
+                    {
+                        #deprecation_notes
+                        let value : #ty = value.try_into()?;
+                        let mut new = #self_into_return_ty;
+                        new.#field_ident = #option::Some(value);
+                        Ok(new)
+                }));
+            } else {
+                trace!("Skipping try_setter for `{}`.", self.field_ident);
+            }
         } else {
             trace!("Skipping setter for `{}`.", self.field_ident);
         }
@@ -131,6 +154,7 @@ macro_rules! default_setter {
     () => {
         Setter {
             enabled: true,
+            try_enabled: false,
             visibility: &syn::Visibility::Public,
             pattern: BuilderPattern::Mutable,
             attrs: &vec![],

From 4cec554ed1e799168cb8401d71b8a06602cefd37 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Mon, 10 Apr 2017 12:51:03 -0700
Subject: [PATCH 03/16] Removed unused feature flag

---
 derive_builder/Cargo.toml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/derive_builder/Cargo.toml b/derive_builder/Cargo.toml
index 4bf760ee..962b2771 100644
--- a/derive_builder/Cargo.toml
+++ b/derive_builder/Cargo.toml
@@ -25,7 +25,6 @@ proc-macro = true
 logging = [ "log", "env_logger", "derive_builder_core/logging" ]
 struct_default = []
 skeptic_tests = ["skeptic"]
-try_setter = []
 
 [dependencies]
 syn = "0.11"

From 85f4d5aa84e1cff67da2065cee406e94244a30ac Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Mon, 10 Apr 2017 12:57:39 -0700
Subject: [PATCH 04/16] Enabled crate-level control over try_setter activation

---
 derive_builder/Cargo.toml                   | 1 +
 derive_builder/src/options/field_options.rs | 2 +-
 derive_builder/tests/try_setter.rs          | 9 ++++++++-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/derive_builder/Cargo.toml b/derive_builder/Cargo.toml
index 962b2771..4bf760ee 100644
--- a/derive_builder/Cargo.toml
+++ b/derive_builder/Cargo.toml
@@ -25,6 +25,7 @@ proc-macro = true
 logging = [ "log", "env_logger", "derive_builder_core/logging" ]
 struct_default = []
 skeptic_tests = ["skeptic"]
+try_setter = []
 
 [dependencies]
 syn = "0.11"
diff --git a/derive_builder/src/options/field_options.rs b/derive_builder/src/options/field_options.rs
index 521d9788..75f8e5d4 100644
--- a/derive_builder/src/options/field_options.rs
+++ b/derive_builder/src/options/field_options.rs
@@ -60,7 +60,7 @@ impl FieldOptions {
     pub fn as_setter<'a>(&'a self) -> Setter<'a> {
         Setter {
             enabled: self.setter_enabled,
-            try_enabled: self.try_setter_enabled,
+            try_enabled: cfg!(feature = "try_setter") && self.try_setter_enabled,
             visibility: &self.setter_visibility,
             pattern: self.builder_pattern,
             attrs: &self.attrs,
diff --git a/derive_builder/tests/try_setter.rs b/derive_builder/tests/try_setter.rs
index 93d3a560..0928cf5d 100644
--- a/derive_builder/tests/try_setter.rs
+++ b/derive_builder/tests/try_setter.rs
@@ -1,10 +1,13 @@
-#![feature(try_from)]
+#![cfg_attr(feature = "try_setter", feature(try_from))]
 
 #[macro_use]
 extern crate derive_builder;
 
+#[allow(unused_imports)]
 mod struct_level {
+    #[cfg(feature = "try_setter")]
     use std::convert::TryFrom;
+    
     use std::net::{IpAddr, AddrParseError};
     use std::str::FromStr;
     use std::string::ToString;
@@ -18,6 +21,7 @@ mod struct_level {
         }
     }
 
+    #[cfg(feature = "try_setter")]
     impl<'a> TryFrom<&'a str> for MyAddr {
         type Err = AddrParseError;
 
@@ -39,6 +43,7 @@ mod struct_level {
     }
 
     #[test]
+    #[cfg(feature = "try_setter")]
     fn fallible_set() {
         let mut builder = LoremBuilder::default();
         let try_result = builder.try_source("1.2.3.4");
@@ -56,6 +61,7 @@ mod struct_level {
             .build()
     }
 
+    #[cfg(feature = "try_setter")]
     fn try_helper() -> Result<Lorem, String> {
         LoremBuilder::default()
             .try_source("1.2.3.4").map_err(|e| e.to_string())?
@@ -64,6 +70,7 @@ mod struct_level {
     }
 
     #[test]
+    #[cfg(feature = "try_setter")]
     fn with_helper() {
         assert_eq!(exact_helper().unwrap(), try_helper().unwrap());
     }

From 0b59e93d5e76871fd24ca620bf40683dee6fbe76 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Mon, 10 Apr 2017 13:11:36 -0700
Subject: [PATCH 05/16] Fixed a dead_code warning in the try_setter test

---
 derive_builder/tests/try_setter.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/derive_builder/tests/try_setter.rs b/derive_builder/tests/try_setter.rs
index 0928cf5d..89b08fe2 100644
--- a/derive_builder/tests/try_setter.rs
+++ b/derive_builder/tests/try_setter.rs
@@ -54,6 +54,8 @@ mod struct_level {
         assert_eq!(built, exact_helper().unwrap());
     }
 
+    // Allow dead code here since the test that uses this depends on the try_setter feature.
+    #[cfg_attr(not(feature = "try_setter"), allow(dead_code))]
     fn exact_helper() -> Result<Lorem, String> {
         LoremBuilder::default()
             .source(IpAddr::from_str("1.2.3.4").unwrap())

From a56e870a54ae72fd46cec7575991aa2286c147b2 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 08:29:15 -0700
Subject: [PATCH 06/16] Incorporated requested source changes

* Renamed try_setter_enabled and try_enabled to `try_setter`
* Removed excess #deprecation_notes
* Removed `|| self.try_enabled`
---
 derive_builder/src/options/field_mode.rs    | 4 ++--
 derive_builder/src/options/field_options.rs | 4 ++--
 derive_builder/src/options/mod.rs           | 8 ++++----
 derive_builder/src/options/struct_mode.rs   | 2 +-
 derive_builder_core/src/setter.rs           | 9 ++++-----
 5 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/derive_builder/src/options/field_mode.rs b/derive_builder/src/options/field_mode.rs
index da012d4c..cea8a321 100644
--- a/derive_builder/src/options/field_mode.rs
+++ b/derive_builder/src/options/field_mode.rs
@@ -81,7 +81,7 @@ impl OptionsBuilder<FieldMode> {
             setter_vis: f!(setter_vis),
             default_expression: f!(default_expression),
             setter_into: f!(setter_into),
-            try_setter_enabled: f!(try_setter_enabled),
+            try_setter: f!(try_setter),
             no_std: f!(no_std),
             mode: mode,
         }
@@ -134,7 +134,7 @@ impl From<OptionsBuilder<FieldMode>> for FieldOptions {
             field_ident: field_ident,
             field_type: field_type,
             setter_into: b.setter_into.unwrap_or(false),
-            try_setter_enabled: b.try_setter_enabled.unwrap_or(false),
+            try_setter: b.try_setter.unwrap_or(false),
             deprecation_notes: b.mode.deprecation_notes.clone(),
             default_expression: b.default_expression.clone(),
             use_default_struct: b.mode.use_default_struct,
diff --git a/derive_builder/src/options/field_options.rs b/derive_builder/src/options/field_options.rs
index 75f8e5d4..0af51db7 100644
--- a/derive_builder/src/options/field_options.rs
+++ b/derive_builder/src/options/field_options.rs
@@ -32,7 +32,7 @@ pub struct FieldOptions {
     /// Bindings to libstd or libcore.
     pub bindings: Bindings,
     /// Enables code generation for the TryInto setter.
-    pub try_setter_enabled: bool,
+    pub try_setter: bool,
 }
 
 impl DefaultExpression {
@@ -60,7 +60,7 @@ impl FieldOptions {
     pub fn as_setter<'a>(&'a self) -> Setter<'a> {
         Setter {
             enabled: self.setter_enabled,
-            try_enabled: cfg!(feature = "try_setter") && self.try_setter_enabled,
+            try_setter: self.try_setter,
             visibility: &self.setter_visibility,
             pattern: self.builder_pattern,
             attrs: &self.attrs,
diff --git a/derive_builder/src/options/mod.rs b/derive_builder/src/options/mod.rs
index 6b8ed902..477270be 100644
--- a/derive_builder/src/options/mod.rs
+++ b/derive_builder/src/options/mod.rs
@@ -45,7 +45,7 @@ pub struct OptionsBuilder<Mode> {
     setter_vis: Option<syn::Visibility>,
     default_expression: Option<DefaultExpression>,
     setter_into: Option<bool>,
-    try_setter_enabled: Option<bool>,
+    try_setter: Option<bool>,
     no_std: Option<bool>,
     mode: Mode,
 }
@@ -67,7 +67,7 @@ impl<Mode> From<Mode> for OptionsBuilder<Mode> {
             setter_prefix: None,
             setter_name: None,
             setter_vis: None,
-            try_setter_enabled: None,
+            try_setter: None,
             default_expression: None,
             setter_into: None,
             no_std: None,
@@ -104,7 +104,7 @@ impl<Mode> OptionsBuilder<Mode> where
     }
     
     impl_setter!{
-        ident: try_setter_enabled,
+        ident: try_setter,
         desc: "try_setter activation",
         map: |x: bool| { x },
     }
@@ -207,7 +207,7 @@ impl<Mode> OptionsBuilder<Mode> where
                 self.setter_enabled(true)
             },
             "try_setter" => {
-                self.try_setter_enabled(true)
+                self.try_setter(true)
             }
             "default" => {
                 if !cfg!(feature = "struct_default") && self.mode.struct_mode() {
diff --git a/derive_builder/src/options/struct_mode.rs b/derive_builder/src/options/struct_mode.rs
index 0c082f97..bf843b65 100644
--- a/derive_builder/src/options/struct_mode.rs
+++ b/derive_builder/src/options/struct_mode.rs
@@ -78,7 +78,7 @@ impl From<OptionsBuilder<StructMode>> for (StructOptions, OptionsBuilder<FieldMo
             setter_prefix: b.setter_prefix,
             setter_vis: b.setter_vis,
             setter_into: b.setter_into,
-            try_setter_enabled: b.try_setter_enabled,
+            try_setter: b.try_setter,
             default_expression: field_default_expression,
             no_std: b.no_std,
             mode: {
diff --git a/derive_builder_core/src/setter.rs b/derive_builder_core/src/setter.rs
index 61db6aee..bec0dba4 100644
--- a/derive_builder_core/src/setter.rs
+++ b/derive_builder_core/src/setter.rs
@@ -35,7 +35,7 @@ pub struct Setter<'a> {
     /// Enables code generation for this setter fn.
     pub enabled: bool,
     /// Enables code generation for the `try_` variant of this setter fn.
-    pub try_enabled: bool,
+    pub try_setter: bool,
     /// Visibility of the setter, e.g. `syn::Visibility::Public`.
     pub visibility: &'a syn::Visibility,
     /// How the setter method takes and returns `self` (e.g. mutably).
@@ -60,7 +60,7 @@ pub struct Setter<'a> {
 
 impl<'a> ToTokens for Setter<'a> {
     fn to_tokens(&self, tokens: &mut Tokens) {
-        if self.enabled || self.try_enabled {
+        if self.enabled {
             trace!("Deriving setter for `{}`.", self.field_ident);
             let ty = self.field_type;
             let pattern = self.pattern;
@@ -120,7 +120,7 @@ impl<'a> ToTokens for Setter<'a> {
                     new
             }));
             
-            if self.try_enabled {
+            if self.try_setter {
                 let try_into = self.bindings.try_into_trait();
                 let try_ty_params = quote!(<VALUE: #try_into<#ty>>);
                 let try_ident = syn::Ident::new(format!("try_{}", ident));
@@ -131,7 +131,6 @@ impl<'a> ToTokens for Setter<'a> {
                     #vis fn #try_ident #try_ty_params (#self_param, value: VALUE)
                         -> #result<#return_ty, VALUE::Err>
                     {
-                        #deprecation_notes
                         let value : #ty = value.try_into()?;
                         let mut new = #self_into_return_ty;
                         new.#field_ident = #option::Some(value);
@@ -154,7 +153,7 @@ macro_rules! default_setter {
     () => {
         Setter {
             enabled: true,
-            try_enabled: false,
+            try_setter: false,
             visibility: &syn::Visibility::Public,
             pattern: BuilderPattern::Mutable,
             attrs: &vec![],

From 6d497bc2ca0462890f596a3af1e2f21b5a75fc6a Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 09:47:27 -0700
Subject: [PATCH 07/16] Tests and documentation

---
 .travis.yml                                   |  2 +-
 derive_builder/CHANGELOG.md                   | 10 +++
 derive_builder/Cargo.toml                     |  1 -
 derive_builder/examples/try_setter.rs         | 52 +++++++++++++++
 derive_builder/src/lib.rs                     | 28 ++++++++
 derive_builder_core/src/setter.rs             | 66 +++++++++++++++++--
 derive_builder_test/Cargo.toml                |  2 +-
 derive_builder_test/tests/compiletests.rs     |  2 +-
 .../tests/run-pass}/try_setter.rs             | 19 +++---
 9 files changed, 164 insertions(+), 18 deletions(-)
 create mode 100644 derive_builder/examples/try_setter.rs
 rename {derive_builder/tests => derive_builder_test/tests/run-pass}/try_setter.rs (79%)

diff --git a/.travis.yml b/.travis.yml
index 31926926..268fd9e5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,7 +10,7 @@ matrix:
     - rust: 1.15.0
       env: JOB=build CARGO_FEATURES="struct_default"
     - rust: nightly
-      env: JOB=build CARGO_FEATURES="compiletests logging"
+      env: JOB=build CARGO_FEATURES="nightlytests logging"
     - rust: nightly
       env: JOB=style_check
   allow_failures:
diff --git a/derive_builder/CHANGELOG.md b/derive_builder/CHANGELOG.md
index 959193bb..348fd1c4 100644
--- a/derive_builder/CHANGELOG.md
+++ b/derive_builder/CHANGELOG.md
@@ -2,6 +2,16 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## [0.4.3] - 2017-04-13
+
+### Added
+- try_setters, e.g. `#[builder(try_setter)]`. These setters are exposed alongside the
+  normal field setters and allow callers to pass in values which have fallible 
+  conversions to the needed type through `TryInto`. This attribute can be used on any 
+  Rust channel, but will only emit setters on nightly when `#![feature(try_from)]` is 
+  declared in the consuming crate's root; this will change when Rust issue 
+  [#33417](https://github.com/rust-lang/rust/issues/33417) is resolved.
+
 ## [0.4.2] - 2017-04-10
 
 ### Fixed
diff --git a/derive_builder/Cargo.toml b/derive_builder/Cargo.toml
index 4bf760ee..962b2771 100644
--- a/derive_builder/Cargo.toml
+++ b/derive_builder/Cargo.toml
@@ -25,7 +25,6 @@ proc-macro = true
 logging = [ "log", "env_logger", "derive_builder_core/logging" ]
 struct_default = []
 skeptic_tests = ["skeptic"]
-try_setter = []
 
 [dependencies]
 syn = "0.11"
diff --git a/derive_builder/examples/try_setter.rs b/derive_builder/examples/try_setter.rs
new file mode 100644
index 00000000..025c7e60
--- /dev/null
+++ b/derive_builder/examples/try_setter.rs
@@ -0,0 +1,52 @@
+//! This example illustrates the use of try-setters.
+#![feature(try_from)]
+
+#[macro_use]
+extern crate derive_builder;
+
+use std::convert::{From, TryFrom};
+use std::net::{IpAddr, AddrParseError};
+use std::str::FromStr;
+use std::string::ToString;
+
+/// Temporary newtype hack around lack of TryFrom implementations
+/// in std. The rust-lang issue on the subject says that there will be a
+/// blanket impl for everything that currently implements FromStr, which
+/// will make this feature much more useful for input validation.
+#[derive(Debug, Clone, PartialEq)]
+pub struct MyAddr(IpAddr);
+
+impl From<IpAddr> for MyAddr {
+    fn from(v: IpAddr) -> Self {
+        MyAddr(v)
+    }
+}
+
+impl<'a> TryFrom<&'a str> for MyAddr {
+    type Err = AddrParseError;
+
+    fn try_from(v: &str) -> Result<Self, AddrParseError> {
+        Ok(MyAddr(IpAddr::from_str(v)?))
+    }
+}
+
+#[derive(Builder, Debug, PartialEq)]
+#[builder(try_setter, setter(into))]
+struct Lorem {
+    pub name: String,
+    pub addr: MyAddr,
+}
+
+fn main() {
+    create("Jane", "1.2.3.4").unwrap();
+    create("Bobby", "").unwrap_err();
+}
+
+fn create(name: &str, addr: &str) -> Result<Lorem, String> {
+    // Fallible and infallible setters can be mixed freely when using
+    // the mutable builder pattern.
+    LoremBuilder::default()
+        .name(name)
+        .try_addr(addr).map_err(|e| e.to_string())?
+        .build()
+}
\ No newline at end of file
diff --git a/derive_builder/src/lib.rs b/derive_builder/src/lib.rs
index 854c5e3e..b14c208b 100644
--- a/derive_builder/src/lib.rs
+++ b/derive_builder/src/lib.rs
@@ -216,6 +216,31 @@
 //! }
 //! ```
 //!
+//! ## Fallible Setters
+//!
+//! Alongside the normal setter methods, you can expose fallible setters which are generic over
+//! the `TryInto` trait. TryInto is a not-yet-stable trait 
+//! (see rust-lang issue [#33417](https://github.com/rust-lang/rust/issues/33417)) similar to
+//! `Into` with the key distinction that the conversion can fail, and therefore produces a `Result`.
+//! 
+//! You can declare the `try_setter` attribute today, and your builder will work on stable Rust -
+//! the fallible setters will automatically light up in future when the `try_from` feature is
+//! stabilized.
+//!
+//!
+//! ```rust,ignore
+//! # #[macro_use]
+//! # extern crate derive_builder;
+//! #
+//! #[derive(Builder, Debug, PartialEq)]
+//! #[builder(try_setter, setter(into))]
+//! struct Lorem {
+//!     pub ipsum: u8,
+//! }
+//! ```
+//!
+//! A complete example of using fallible setters is available in `examples/try_setter.rs`.
+//!
 //! ## Default Values
 //!
 //! You can define default values for each field via annotation by `#[builder(default="...")]`,
@@ -366,6 +391,9 @@
 //! - If derive_builder depends on your crate, and vice versa, then a cyclic
 //!   dependency would occur. To break it you could try to depend on the
 //!   [`derive_builder_core`] crate instead.
+//! - The `try_setter` attribute and `owned` builder pattern are not compatible in practice;
+//!   an error during building will consume the builder, making it impossible to continue
+//!   construction.
 //!
 //! ## Debugging Info
 //!
diff --git a/derive_builder_core/src/setter.rs b/derive_builder_core/src/setter.rs
index bec0dba4..b8ef3ce8 100644
--- a/derive_builder_core/src/setter.rs
+++ b/derive_builder_core/src/setter.rs
@@ -131,9 +131,9 @@ impl<'a> ToTokens for Setter<'a> {
                     #vis fn #try_ident #try_ty_params (#self_param, value: VALUE)
                         -> #result<#return_ty, VALUE::Err>
                     {
-                        let value : #ty = value.try_into()?;
+                        let converted : #ty = value.try_into()?;
                         let mut new = #self_into_return_ty;
-                        new.#field_ident = #option::Some(value);
+                        new.#field_ident = #option::Some(converted);
                         Ok(new)
                 }));
             } else {
@@ -244,7 +244,7 @@ mod tests {
         ));
     }
 
-    // including
+    // including try_setter
     #[test]
     fn full() {
         let attrs = vec![syn::parse_outer_attr("#[some_attr]").unwrap()];
@@ -256,14 +256,36 @@ mod tests {
         setter.attrs = attrs.as_slice();
         setter.generic_into = true;
         setter.deprecation_notes = &deprecated;
+        setter.try_setter = true;
+
+        // Had to hoist these out to avoid a recursion limit in the quote!
+        // macro invocation below.
+        let action = quote!(
+            let mut new = self;
+            new.foo = ::std::option::Option::Some(value.into());
+            new
+        );
+        
+        let try_action = quote!(
+            let converted : Foo = value.try_into()?;
+            let mut new = self;
+            new.foo = ::std::option::Option::Some(converted);
+            Ok(new)
+        );
+
+        println!("{}", quote!(#setter));
 
         assert_eq!(quote!(#setter), quote!(
             #[some_attr]
             pub fn foo <VALUE: ::std::convert::Into<Foo>>(&mut self, value: VALUE) -> &mut Self {
                 #deprecated
-                let mut new = self;
-                new.foo = ::std::option::Option::Some(value.into());
-                new
+                #action
+            }
+                        
+            #[some_attr]
+            pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE) 
+                -> ::std::result::Result<&mut Self, VALUE::Err> {
+                #try_action
             }
         ));
     }
@@ -305,4 +327,36 @@ mod tests {
 
         assert_eq!(quote!(#setter), quote!());
     }
+    
+    #[test]
+    fn try_setter() {
+        let mut setter : Setter = default_setter!();
+        setter.pattern = BuilderPattern::Mutable;
+        setter.try_setter = true;
+        
+        let setter_quote = quote!(
+            pub fn foo(&mut self, value: Foo) -> &mut Self {
+                let mut new = self;
+                new.foo = ::std::option::Option::Some(value);
+                new
+            }
+        );
+        
+        // hoisting necessary to avoid recursion limit.
+        let try_setter_body = quote!(
+            let converted : Foo = value.try_into()?;
+            let mut new = self;
+            new.foo = ::std::option::Option::Some(converted);
+            Ok(new)
+        );
+        
+        assert_eq!(quote!(#setter), quote!(
+            #setter_quote
+            
+            pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE) 
+                -> ::std::result::Result<&mut Self, VALUE::Err> {
+                #try_setter_body
+            }
+        ));
+    }
 }
diff --git a/derive_builder_test/Cargo.toml b/derive_builder_test/Cargo.toml
index d93b78b1..a687f151 100644
--- a/derive_builder_test/Cargo.toml
+++ b/derive_builder_test/Cargo.toml
@@ -9,7 +9,7 @@ publish = false
 path = "src/lib.rs"
 
 [features]
-compiletests = ["compiletest_rs"]
+nightlytests = ["compiletest_rs"]
 logging = [ "derive_builder/logging" ]
 struct_default = [ "derive_builder/struct_default" ]
 
diff --git a/derive_builder_test/tests/compiletests.rs b/derive_builder_test/tests/compiletests.rs
index 23c07b02..022793cd 100644
--- a/derive_builder_test/tests/compiletests.rs
+++ b/derive_builder_test/tests/compiletests.rs
@@ -1,4 +1,4 @@
-#![cfg(feature = "compiletests")]
+#![cfg(feature = "nightlytests")]
 extern crate compiletest_rs as compiletest;
 
 // note:
diff --git a/derive_builder/tests/try_setter.rs b/derive_builder_test/tests/run-pass/try_setter.rs
similarity index 79%
rename from derive_builder/tests/try_setter.rs
rename to derive_builder_test/tests/run-pass/try_setter.rs
index 89b08fe2..f2492b2f 100644
--- a/derive_builder/tests/try_setter.rs
+++ b/derive_builder_test/tests/run-pass/try_setter.rs
@@ -1,11 +1,11 @@
-#![cfg_attr(feature = "try_setter", feature(try_from))]
+#![cfg_attr(feature = "nightlytests", feature(try_from))]
 
 #[macro_use]
 extern crate derive_builder;
 
 #[allow(unused_imports)]
 mod struct_level {
-    #[cfg(feature = "try_setter")]
+    #[cfg(feature = "try_from")]
     use std::convert::TryFrom;
     
     use std::net::{IpAddr, AddrParseError};
@@ -21,7 +21,7 @@ mod struct_level {
         }
     }
 
-    #[cfg(feature = "try_setter")]
+    #[cfg(feature = "nightlytests")]
     impl<'a> TryFrom<&'a str> for MyAddr {
         type Err = AddrParseError;
 
@@ -39,11 +39,14 @@ mod struct_level {
 
     #[test]
     fn infallible_set() {
-        let _ = LoremBuilder::default().source(IpAddr::from_str("1.2.3.4").unwrap()).build();
+        let _ = LoremBuilder::default()
+            .source(IpAddr::from_str("1.2.3.4").unwrap())
+            .dest(IpAddr::from_str("0.0.0.0").unwrap())
+            .build();
     }
 
     #[test]
-    #[cfg(feature = "try_setter")]
+    #[cfg(feature = "nightlytests")]
     fn fallible_set() {
         let mut builder = LoremBuilder::default();
         let try_result = builder.try_source("1.2.3.4");
@@ -55,7 +58,7 @@ mod struct_level {
     }
 
     // Allow dead code here since the test that uses this depends on the try_setter feature.
-    #[cfg_attr(not(feature = "try_setter"), allow(dead_code))]
+    #[cfg_attr(not(feature = "nightlytests"), allow(dead_code))]
     fn exact_helper() -> Result<Lorem, String> {
         LoremBuilder::default()
             .source(IpAddr::from_str("1.2.3.4").unwrap())
@@ -63,7 +66,7 @@ mod struct_level {
             .build()
     }
 
-    #[cfg(feature = "try_setter")]
+    #[cfg(feature = "nightlytests")]
     fn try_helper() -> Result<Lorem, String> {
         LoremBuilder::default()
             .try_source("1.2.3.4").map_err(|e| e.to_string())?
@@ -72,7 +75,7 @@ mod struct_level {
     }
 
     #[test]
-    #[cfg(feature = "try_setter")]
+    #[cfg(feature = "nightlytests")]
     fn with_helper() {
         assert_eq!(exact_helper().unwrap(), try_helper().unwrap());
     }

From 24d7eb4cbec8434963c34f9b4cad8c758efaf248 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 09:58:38 -0700
Subject: [PATCH 08/16] Updated integration tests

---
 .../tests/run-pass/try_setter.rs              | 95 ++++---------------
 1 file changed, 18 insertions(+), 77 deletions(-)

diff --git a/derive_builder_test/tests/run-pass/try_setter.rs b/derive_builder_test/tests/run-pass/try_setter.rs
index f2492b2f..4783809c 100644
--- a/derive_builder_test/tests/run-pass/try_setter.rs
+++ b/derive_builder_test/tests/run-pass/try_setter.rs
@@ -1,82 +1,23 @@
 #![cfg_attr(feature = "nightlytests", feature(try_from))]
 
+use std::net::IpAddr;
+
 #[macro_use]
 extern crate derive_builder;
 
-#[allow(unused_imports)]
-mod struct_level {
-    #[cfg(feature = "try_from")]
-    use std::convert::TryFrom;
-    
-    use std::net::{IpAddr, AddrParseError};
-    use std::str::FromStr;
-    use std::string::ToString;
-
-    #[derive(Debug, Clone, PartialEq)]
-    pub struct MyAddr(IpAddr);
-
-    impl From<IpAddr> for MyAddr {
-        fn from(v: IpAddr) -> Self {
-            MyAddr(v)
-        }
-    }
-
-    #[cfg(feature = "nightlytests")]
-    impl<'a> TryFrom<&'a str> for MyAddr {
-        type Err = AddrParseError;
-
-        fn try_from(v: &str) -> Result<Self, Self::Err> {
-            Ok(MyAddr(v.parse()?))
-        }
-    }
-
-    #[derive(Debug, PartialEq, Builder)]
-    #[builder(try_setter, setter(into))]
-    struct Lorem {
-        pub source: MyAddr,
-        pub dest: MyAddr,
-    }
-
-    #[test]
-    fn infallible_set() {
-        let _ = LoremBuilder::default()
-            .source(IpAddr::from_str("1.2.3.4").unwrap())
-            .dest(IpAddr::from_str("0.0.0.0").unwrap())
-            .build();
-    }
-
-    #[test]
-    #[cfg(feature = "nightlytests")]
-    fn fallible_set() {
-        let mut builder = LoremBuilder::default();
-        let try_result = builder.try_source("1.2.3.4");
-        let built = try_result.expect("Passed well-formed address")
-            .dest(IpAddr::from_str("0.0.0.0").unwrap())
-            .build()
-            .unwrap();
-        assert_eq!(built, exact_helper().unwrap());
-    }
-
-    // Allow dead code here since the test that uses this depends on the try_setter feature.
-    #[cfg_attr(not(feature = "nightlytests"), allow(dead_code))]
-    fn exact_helper() -> Result<Lorem, String> {
-        LoremBuilder::default()
-            .source(IpAddr::from_str("1.2.3.4").unwrap())
-            .dest(IpAddr::from_str("0.0.0.0").unwrap())
-            .build()
-    }
-
-    #[cfg(feature = "nightlytests")]
-    fn try_helper() -> Result<Lorem, String> {
-        LoremBuilder::default()
-            .try_source("1.2.3.4").map_err(|e| e.to_string())?
-            .try_dest("0.0.0.0").map_err(|e| e.to_string())?
-            .build()
-    }
-
-    #[test]
-    #[cfg(feature = "nightlytests")]
-    fn with_helper() {
-        assert_eq!(exact_helper().unwrap(), try_helper().unwrap());
-    }
-}
\ No newline at end of file
+#[derive(Debug, Clone, Builder)]
+#[builder(try_setter)]
+pub struct Lorem {
+    source: IpAddr,
+    dest: IpAddr,
+    name: String,
+}
+
+#[derive(Default, Debug, Clone, Builder)]
+#[builder(default, setter(prefix = "set", into), try_setter)]
+pub struct Ipsum {
+    source: Option<IpAddr>,
+    name: String,
+}
+
+fn main() { }

From 79491a563d3acb42a76f6056b34b83afb003da40 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 10:40:52 -0700
Subject: [PATCH 09/16] Fixed recursion limit for tests in derive_builder_core

---
 derive_builder_core/src/lib.rs    |  1 +
 derive_builder_core/src/setter.rs | 45 +++++++++----------------------
 2 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/derive_builder_core/src/lib.rs b/derive_builder_core/src/lib.rs
index e97873e0..9518ada5 100644
--- a/derive_builder_core/src/lib.rs
+++ b/derive_builder_core/src/lib.rs
@@ -22,6 +22,7 @@
 //! [`derive_builder_core`]: https://!crates.io/crates/derive_builder_core
 
 #![deny(warnings, missing_docs)]
+#![cfg_attr(test, recursion_limit = "100")]
 
 extern crate proc_macro;
 extern crate syn;
diff --git a/derive_builder_core/src/setter.rs b/derive_builder_core/src/setter.rs
index b8ef3ce8..0d6ea26d 100644
--- a/derive_builder_core/src/setter.rs
+++ b/derive_builder_core/src/setter.rs
@@ -258,34 +258,22 @@ mod tests {
         setter.deprecation_notes = &deprecated;
         setter.try_setter = true;
 
-        // Had to hoist these out to avoid a recursion limit in the quote!
-        // macro invocation below.
-        let action = quote!(
-            let mut new = self;
-            new.foo = ::std::option::Option::Some(value.into());
-            new
-        );
-        
-        let try_action = quote!(
-            let converted : Foo = value.try_into()?;
-            let mut new = self;
-            new.foo = ::std::option::Option::Some(converted);
-            Ok(new)
-        );
-
-        println!("{}", quote!(#setter));
-
         assert_eq!(quote!(#setter), quote!(
             #[some_attr]
             pub fn foo <VALUE: ::std::convert::Into<Foo>>(&mut self, value: VALUE) -> &mut Self {
                 #deprecated
-                #action
+                let mut new = self;
+                new.foo = ::std::option::Option::Some(value.into());
+                new
             }
                         
             #[some_attr]
             pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE) 
                 -> ::std::result::Result<&mut Self, VALUE::Err> {
-                #try_action
+                let converted : Foo = value.try_into()?;
+                let mut new = self;
+                new.foo = ::std::option::Option::Some(converted);
+                Ok(new)
             }
         ));
     }
@@ -334,28 +322,19 @@ mod tests {
         setter.pattern = BuilderPattern::Mutable;
         setter.try_setter = true;
         
-        let setter_quote = quote!(
+        assert_eq!(quote!(#setter), quote!(
             pub fn foo(&mut self, value: Foo) -> &mut Self {
                 let mut new = self;
                 new.foo = ::std::option::Option::Some(value);
                 new
             }
-        );
-        
-        // hoisting necessary to avoid recursion limit.
-        let try_setter_body = quote!(
-            let converted : Foo = value.try_into()?;
-            let mut new = self;
-            new.foo = ::std::option::Option::Some(converted);
-            Ok(new)
-        );
-        
-        assert_eq!(quote!(#setter), quote!(
-            #setter_quote
             
             pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE) 
                 -> ::std::result::Result<&mut Self, VALUE::Err> {
-                #try_setter_body
+                let converted : Foo = value.try_into()?;
+                let mut new = self;
+                new.foo = ::std::option::Option::Some(converted);
+                Ok(new)
             }
         ));
     }

From fd7deeb0b5b6a4b97b667f88cd1e1d259f0ac028 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 11:10:50 -0700
Subject: [PATCH 10/16] Updated docs and changelog to reflect lack of lightup

---
 derive_builder/CHANGELOG.md           |  8 ++++----
 derive_builder/examples/try_setter.rs |  4 +++-
 derive_builder/src/lib.rs             | 27 ++++++++++++++++++++++++---
 3 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/derive_builder/CHANGELOG.md b/derive_builder/CHANGELOG.md
index 348fd1c4..c5bb3a99 100644
--- a/derive_builder/CHANGELOG.md
+++ b/derive_builder/CHANGELOG.md
@@ -6,10 +6,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 - try_setters, e.g. `#[builder(try_setter)]`. These setters are exposed alongside the
-  normal field setters and allow callers to pass in values which have fallible 
-  conversions to the needed type through `TryInto`. This attribute can be used on any 
-  Rust channel, but will only emit setters on nightly when `#![feature(try_from)]` is 
-  declared in the consuming crate's root; this will change when Rust issue 
+  normal field setters and allow callers to pass in values which have 
+  fallible conversions to the needed type through `TryInto`. This attribute 
+  can only be used on nightly when until `#![feature(try_from)]` is declared 
+  in the consuming crate's root; this will change when Rust issue 
   [#33417](https://github.com/rust-lang/rust/issues/33417) is resolved.
 
 ## [0.4.2] - 2017-04-10
diff --git a/derive_builder/examples/try_setter.rs b/derive_builder/examples/try_setter.rs
index 025c7e60..6352ef32 100644
--- a/derive_builder/examples/try_setter.rs
+++ b/derive_builder/examples/try_setter.rs
@@ -1,10 +1,12 @@
 //! This example illustrates the use of try-setters.
+//! Tests are suppressed so that this doesn't break the build on stable.
+#![cfg(not(test))]
 #![feature(try_from)]
 
 #[macro_use]
 extern crate derive_builder;
 
-use std::convert::{From, TryFrom};
+use std::convert::TryFrom;
 use std::net::{IpAddr, AddrParseError};
 use std::str::FromStr;
 use std::string::ToString;
diff --git a/derive_builder/src/lib.rs b/derive_builder/src/lib.rs
index b14c208b..60bdf183 100644
--- a/derive_builder/src/lib.rs
+++ b/derive_builder/src/lib.rs
@@ -223,20 +223,41 @@
 //! (see rust-lang issue [#33417](https://github.com/rust-lang/rust/issues/33417)) similar to
 //! `Into` with the key distinction that the conversion can fail, and therefore produces a `Result`.
 //! 
-//! You can declare the `try_setter` attribute today, and your builder will work on stable Rust -
-//! the fallible setters will automatically light up in future when the `try_from` feature is
-//! stabilized.
+//! You can only declare the `try_setter` attribute today if you're targeting nightly, and you have
+//! to add `#![feature(try_from)]` to your crate to use it.
 //!
 //!
 //! ```rust,ignore
+//! #![feature(try_from)]
 //! # #[macro_use]
 //! # extern crate derive_builder;
 //! #
 //! #[derive(Builder, Debug, PartialEq)]
 //! #[builder(try_setter, setter(into))]
 //! struct Lorem {
+//!     pub name: String,
 //!     pub ipsum: u8,
 //! }
+//! 
+//! #[derive(Builder, Debug, PartialEq)]
+//! struct Ipsum {
+//!     #[builder(try_setter, setter(into, name = "foo"))]
+//!     pub dolor: u8,
+//! }
+//!
+//! fn main() {
+//!    LoremBuilder::default()
+//!        .try_ipsum(1u16).unwrap()
+//!        .name("hello")
+//!        .build()
+//!        .expect("1 fits into a u8");
+//!
+//!    IpsumBuilder::default()
+//!        .try_foo(1u16)
+//!        .unwrap()
+//!        .build()
+//!        .expect("1 fits into a u8");
+//! }
 //! ```
 //!
 //! A complete example of using fallible setters is available in `examples/try_setter.rs`.

From 79e447430fe53d600c2937c3d95dd257baf0ca96 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 11:12:16 -0700
Subject: [PATCH 11/16] Moved try_setter integration test out of compiletests

---
 derive_builder_test/tests/{run-pass => }/try_setter.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 rename derive_builder_test/tests/{run-pass => }/try_setter.rs (96%)

diff --git a/derive_builder_test/tests/run-pass/try_setter.rs b/derive_builder_test/tests/try_setter.rs
similarity index 96%
rename from derive_builder_test/tests/run-pass/try_setter.rs
rename to derive_builder_test/tests/try_setter.rs
index 4783809c..c5a238ae 100644
--- a/derive_builder_test/tests/run-pass/try_setter.rs
+++ b/derive_builder_test/tests/try_setter.rs
@@ -20,4 +20,4 @@ pub struct Ipsum {
     name: String,
 }
 
-fn main() { }
+fn main() { }
\ No newline at end of file

From 0600c052ff0b79b0ed7ff713d44727a0af94131d Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 11:47:32 -0700
Subject: [PATCH 12/16] Trying to fix tests again by blocking the try_setter
 example from running

---
 derive_builder/examples/try_setter.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/derive_builder/examples/try_setter.rs b/derive_builder/examples/try_setter.rs
index 6352ef32..76ccc326 100644
--- a/derive_builder/examples/try_setter.rs
+++ b/derive_builder/examples/try_setter.rs
@@ -1,6 +1,6 @@
 //! This example illustrates the use of try-setters.
-//! Tests are suppressed so that this doesn't break the build on stable.
-#![cfg(not(test))]
+//! Tests are suppressed using a fake feature so that this doesn't break the build on stable.
+#![cfg(feature = "try_from")]
 #![feature(try_from)]
 
 #[macro_use]

From 15104198b6b67f057143440ad94c9aa1a9319a13 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 12:57:25 -0700
Subject: [PATCH 13/16] Revived integration tests

---
 derive_builder_test/tests/try_setter.rs | 111 ++++++++++++++++++++----
 1 file changed, 93 insertions(+), 18 deletions(-)

diff --git a/derive_builder_test/tests/try_setter.rs b/derive_builder_test/tests/try_setter.rs
index c5a238ae..b0d9d0a8 100644
--- a/derive_builder_test/tests/try_setter.rs
+++ b/derive_builder_test/tests/try_setter.rs
@@ -1,23 +1,98 @@
 #![cfg_attr(feature = "nightlytests", feature(try_from))]
 
-use std::net::IpAddr;
-
 #[macro_use]
 extern crate derive_builder;
 
-#[derive(Debug, Clone, Builder)]
-#[builder(try_setter)]
-pub struct Lorem {
-    source: IpAddr,
-    dest: IpAddr,
-    name: String,
-}
-
-#[derive(Default, Debug, Clone, Builder)]
-#[builder(default, setter(prefix = "set", into), try_setter)]
-pub struct Ipsum {
-    source: Option<IpAddr>,
-    name: String,
-}
-
-fn main() { }
\ No newline at end of file
+#[allow(unused_imports)]
+mod struct_level {
+    #[cfg(feature = "nightlytests")]
+    use std::convert::TryFrom;
+    
+    use std::net::{IpAddr, AddrParseError};
+    use std::str::FromStr;
+    use std::string::ToString;
+
+    #[derive(Debug, Clone, PartialEq)]
+    pub struct MyAddr(IpAddr);
+
+    impl From<IpAddr> for MyAddr {
+        fn from(v: IpAddr) -> Self {
+            MyAddr(v)
+        }
+    }
+
+    #[cfg(feature = "nightlytests")]
+    impl<'a> TryFrom<&'a str> for MyAddr {
+        type Err = AddrParseError;
+
+        fn try_from(v: &str) -> Result<Self, Self::Err> {
+            Ok(MyAddr(v.parse()?))
+        }
+    }
+
+    #[derive(Debug, PartialEq, Builder)]
+    #[builder(try_setter, setter(into))]
+    struct Lorem {
+        pub source: MyAddr,
+        pub dest: MyAddr,
+    }
+    
+    #[derive(Debug, PartialEq, Builder)]
+    #[builder(try_setter, setter(into, prefix = "set"))]
+    struct Ipsum {
+        pub source: MyAddr
+    }
+    
+    // Allow dead code here since the test that uses this depends on the try_setter feature.
+    #[cfg_attr(not(feature = "nightlytests"), allow(dead_code))]
+    fn exact_helper() -> Result<Lorem, String> {
+        LoremBuilder::default()
+            .source(IpAddr::from_str("1.2.3.4").unwrap())
+            .dest(IpAddr::from_str("0.0.0.0").unwrap())
+            .build()
+    }
+
+    #[cfg(feature = "nightlytests")]
+    fn try_helper() -> Result<Lorem, String> {
+        LoremBuilder::default()
+            .try_source("1.2.3.4").map_err(|e| e.to_string())?
+            .try_dest("0.0.0.0").map_err(|e| e.to_string())?
+            .build()
+    }
+
+    #[test]
+    fn infallible_set() {
+        let _ = LoremBuilder::default()
+            .source(IpAddr::from_str("1.2.3.4").unwrap())
+            .dest(IpAddr::from_str("0.0.0.0").unwrap())
+            .build();
+    }
+
+    #[test]
+    #[cfg(feature = "nightlytests")]
+    fn fallible_set() {
+        let mut builder = LoremBuilder::default();
+        let try_result = builder.try_source("1.2.3.4");
+        let built = try_result.expect("Passed well-formed address")
+            .dest(IpAddr::from_str("0.0.0.0").unwrap())
+            .build()
+            .unwrap();
+        assert_eq!(built, exact_helper().unwrap());
+    }
+
+    #[test]
+    #[cfg(feature = "nightlytests")]
+    fn with_helper() {
+        assert_eq!(exact_helper().unwrap(), try_helper().unwrap());
+    }
+    
+    #[test]
+    #[cfg(feature = "nightlytests")]
+    fn renamed() {
+        IpsumBuilder::default()
+            .try_set_source("0.0.0.0")
+            .unwrap()
+            .build()
+            .expect("All fields were provided");
+    }
+}
\ No newline at end of file

From ec3cc06c6b6fcc0765545500647c53b54be91fa3 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 15:58:24 -0700
Subject: [PATCH 14/16] Removing the try_setter example outright.

That example seems to be causing many/all of the failures.
---
 derive_builder/examples/try_setter.rs | 54 ---------------------------
 derive_builder/src/lib.rs             |  2 -
 2 files changed, 56 deletions(-)
 delete mode 100644 derive_builder/examples/try_setter.rs

diff --git a/derive_builder/examples/try_setter.rs b/derive_builder/examples/try_setter.rs
deleted file mode 100644
index 76ccc326..00000000
--- a/derive_builder/examples/try_setter.rs
+++ /dev/null
@@ -1,54 +0,0 @@
-//! This example illustrates the use of try-setters.
-//! Tests are suppressed using a fake feature so that this doesn't break the build on stable.
-#![cfg(feature = "try_from")]
-#![feature(try_from)]
-
-#[macro_use]
-extern crate derive_builder;
-
-use std::convert::TryFrom;
-use std::net::{IpAddr, AddrParseError};
-use std::str::FromStr;
-use std::string::ToString;
-
-/// Temporary newtype hack around lack of TryFrom implementations
-/// in std. The rust-lang issue on the subject says that there will be a
-/// blanket impl for everything that currently implements FromStr, which
-/// will make this feature much more useful for input validation.
-#[derive(Debug, Clone, PartialEq)]
-pub struct MyAddr(IpAddr);
-
-impl From<IpAddr> for MyAddr {
-    fn from(v: IpAddr) -> Self {
-        MyAddr(v)
-    }
-}
-
-impl<'a> TryFrom<&'a str> for MyAddr {
-    type Err = AddrParseError;
-
-    fn try_from(v: &str) -> Result<Self, AddrParseError> {
-        Ok(MyAddr(IpAddr::from_str(v)?))
-    }
-}
-
-#[derive(Builder, Debug, PartialEq)]
-#[builder(try_setter, setter(into))]
-struct Lorem {
-    pub name: String,
-    pub addr: MyAddr,
-}
-
-fn main() {
-    create("Jane", "1.2.3.4").unwrap();
-    create("Bobby", "").unwrap_err();
-}
-
-fn create(name: &str, addr: &str) -> Result<Lorem, String> {
-    // Fallible and infallible setters can be mixed freely when using
-    // the mutable builder pattern.
-    LoremBuilder::default()
-        .name(name)
-        .try_addr(addr).map_err(|e| e.to_string())?
-        .build()
-}
\ No newline at end of file
diff --git a/derive_builder/src/lib.rs b/derive_builder/src/lib.rs
index 60bdf183..3a6e85c2 100644
--- a/derive_builder/src/lib.rs
+++ b/derive_builder/src/lib.rs
@@ -260,8 +260,6 @@
 //! }
 //! ```
 //!
-//! A complete example of using fallible setters is available in `examples/try_setter.rs`.
-//!
 //! ## Default Values
 //!
 //! You can define default values for each field via annotation by `#[builder(default="...")]`,

From 12daa64cc159678659b3d2ae4bba48bdcce2a0a4 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 16:31:29 -0700
Subject: [PATCH 15/16] Made the entire try_setter test dependent on nightly.

---
 derive_builder_test/tests/try_setter.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/derive_builder_test/tests/try_setter.rs b/derive_builder_test/tests/try_setter.rs
index b0d9d0a8..acdf5e17 100644
--- a/derive_builder_test/tests/try_setter.rs
+++ b/derive_builder_test/tests/try_setter.rs
@@ -3,6 +3,7 @@
 #[macro_use]
 extern crate derive_builder;
 
+#[cfg(feature = "nightlytests")]
 #[allow(unused_imports)]
 mod struct_level {
     #[cfg(feature = "nightlytests")]
@@ -43,8 +44,6 @@ mod struct_level {
         pub source: MyAddr
     }
     
-    // Allow dead code here since the test that uses this depends on the try_setter feature.
-    #[cfg_attr(not(feature = "nightlytests"), allow(dead_code))]
     fn exact_helper() -> Result<Lorem, String> {
         LoremBuilder::default()
             .source(IpAddr::from_str("1.2.3.4").unwrap())

From c629cbd1b1ed8662dac9d21ab960d9999fc2f1e0 Mon Sep 17 00:00:00 2001
From: Ted Driggs <ted.driggs@outlook.com>
Date: Tue, 11 Apr 2017 16:46:05 -0700
Subject: [PATCH 16/16] TryFrom's associated type was changed from Err to Error

https://github.com/rust-lang/rust/pull/40281
---
 derive_builder_core/src/setter.rs       | 6 +++---
 derive_builder_test/tests/try_setter.rs | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/derive_builder_core/src/setter.rs b/derive_builder_core/src/setter.rs
index 0d6ea26d..1841c1c7 100644
--- a/derive_builder_core/src/setter.rs
+++ b/derive_builder_core/src/setter.rs
@@ -129,7 +129,7 @@ impl<'a> ToTokens for Setter<'a> {
                 tokens.append(quote!(
                     #(#attrs)*
                     #vis fn #try_ident #try_ty_params (#self_param, value: VALUE)
-                        -> #result<#return_ty, VALUE::Err>
+                        -> #result<#return_ty, VALUE::Error>
                     {
                         let converted : #ty = value.try_into()?;
                         let mut new = #self_into_return_ty;
@@ -269,7 +269,7 @@ mod tests {
                         
             #[some_attr]
             pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE) 
-                -> ::std::result::Result<&mut Self, VALUE::Err> {
+                -> ::std::result::Result<&mut Self, VALUE::Error> {
                 let converted : Foo = value.try_into()?;
                 let mut new = self;
                 new.foo = ::std::option::Option::Some(converted);
@@ -330,7 +330,7 @@ mod tests {
             }
             
             pub fn try_foo<VALUE: ::std::convert::TryInto<Foo>>(&mut self, value: VALUE) 
-                -> ::std::result::Result<&mut Self, VALUE::Err> {
+                -> ::std::result::Result<&mut Self, VALUE::Error> {
                 let converted : Foo = value.try_into()?;
                 let mut new = self;
                 new.foo = ::std::option::Option::Some(converted);
diff --git a/derive_builder_test/tests/try_setter.rs b/derive_builder_test/tests/try_setter.rs
index acdf5e17..49d28086 100644
--- a/derive_builder_test/tests/try_setter.rs
+++ b/derive_builder_test/tests/try_setter.rs
@@ -24,9 +24,9 @@ mod struct_level {
 
     #[cfg(feature = "nightlytests")]
     impl<'a> TryFrom<&'a str> for MyAddr {
-        type Err = AddrParseError;
+        type Error = AddrParseError;
 
-        fn try_from(v: &str) -> Result<Self, Self::Err> {
+        fn try_from(v: &str) -> Result<Self, Self::Error> {
             Ok(MyAddr(v.parse()?))
         }
     }