Implement initial option for brace style for non-fn items.

src/config.rs

@@ -302,4 +302,5 @@ create_config! {
     take_source_hints: bool, true, "Retain some formatting characteristics from the source code";
     hard_tabs: bool, false, "Use tab characters for indentation, spaces for alignment";
     wrap_comments: bool, false, "Break comments to fit on the line";
+    item_brace_style: BraceStyle, BraceStyle::SameLineWhere, "Brace style for structs and enums";
 }

src/items.rs

@@ -634,10 +634,17 @@ impl<'a> FmtVisitor<'a> {
         let header_str = self.format_header("enum ", ident, vis);
         self.buffer.push_str(&header_str);
 
+        let separator = if self.config.item_brace_style == BraceStyle::AlwaysNextLine &&
+                           !enum_def.variants.is_empty() {
+            format!("\n{}", self.block_indent.to_string(self.config))
+        } else {
+            " ".to_owned()
+        };
         let enum_snippet = self.snippet(span);
         let body_start = span.lo + BytePos(enum_snippet.find_uncommented("{").unwrap() as u32 + 1);
         let generics_str = self.format_generics(generics,
                                                 "{",
+                                                &separator,
                                                 "{",
                                                 self.block_indent,
                                                 self.block_indent.block_indent(self.config),
@@ -813,16 +820,24 @@ impl<'a> FmtVisitor<'a> {
 
         let body_lo = span_after(span, "{", self.codemap);
 
+        let separator = if self.config.item_brace_style == BraceStyle::AlwaysNextLine &&
+                           !fields.is_empty() {
+            format!("\n{}", self.block_indent.to_string(self.config))
+        } else {
+            " ".to_owned()
+        };
+
         let generics_str = match generics {
             Some(g) => {
                 try_opt!(self.format_generics(g,
                                               "{",
+                                              &separator,
                                               "{",
                                               offset,
                                               offset + header_str.len(),
                                               mk_sp(span.lo, body_lo)))
             }
-            None => " {".to_owned(),
+            None => format!("{}{{", separator),
         };
         result.push_str(&generics_str);
 
@@ -954,6 +969,7 @@ impl<'a> FmtVisitor<'a> {
     fn format_generics(&self,
                        generics: &ast::Generics,
                        opener: &str,
+                       separator: &str,
                        terminator: &str,
                        offset: Indent,
                        generics_offset: Indent,
@@ -973,7 +989,7 @@ impl<'a> FmtVisitor<'a> {
             result.push_str(&self.block_indent.to_string(self.config));
             result.push_str(opener);
         } else {
-            result.push(' ');
+            result.push_str(separator);
             result.push_str(opener);
         }
 

tests/source/item-brace-style.rs

@@ -0,0 +1,16 @@
+// rustfmt-item_brace_style: AlwaysNextLine
+
+mod M {
+    enum A {
+        A,
+    }
+
+    struct B {
+        b: i32,
+    }
+
+    // For empty enums and structs, the brace remains on the same line.
+    enum C {}
+
+    struct D {}
+}

tests/target/item-brace-style.rs

@@ -0,0 +1,18 @@
+// rustfmt-item_brace_style: AlwaysNextLine
+
+mod M {
+    enum A
+    {
+        A,
+    }
+
+    struct B
+    {
+        b: i32,
+    }
+
+    // For empty enums and structs, the brace remains on the same line.
+    enum C {}
+
+    struct D {}
+}