4 files changed, 28 insertions, 7 deletions
diff --git a/src/api/android/mod.rs b/src/api/android/mod.rs
index f42caeb..433472c 100644
--- a/src/api/android/mod.rs
+++ b/src/api/android/mod.rs
@@ -65,6 +65,11 @@ impl MonitorId {
     }
 }
 
+#[derive(Default)]
+pub struct PlatformSpecificWindowBuilderAttributes;
+#[derive(Default)]
+pub struct PlatformSpecificHeadlessBuilderAttributes;
+
 pub struct PollEventsIterator<'a> {
     window: &'a Window,
 }
@@ -116,7 +121,8 @@ impl<'a> Iterator for WaitEventsIterator<'a> {
 
 impl Window {
     pub fn new(win_attribs: &WindowAttributes, pf_reqs: &PixelFormatRequirements,
-               opengl: &GlAttributes<&Window>) -> Result<Window, CreationError>
+               opengl: &GlAttributes<&Window>, _: &PlatformSpecificWindowBuilderAttributes)
+               -> Result<Window, CreationError>
     {
         use std::{mem, ptr};
 
@@ -302,7 +308,9 @@ pub struct HeadlessContext(EglContext);
 impl HeadlessContext {
     /// See the docs in the crate root file.
     pub fn new(dimensions: (u32, u32), pf_reqs: &PixelFormatRequirements,
-               opengl: &GlAttributes<&HeadlessContext>) -> Result<HeadlessContext, CreationError>
+               opengl: &GlAttributes<&HeadlessContext>,
+               _: &PlatformSpecificHeadlessBuilderAttributes)
+               -> Result<HeadlessContext, CreationError>
     {
         let opengl = opengl.clone().map_sharing(|c| &c.0);
         let context = try!(EglContext::new(egl::ffi::egl::Egl, pf_reqs, &opengl,
diff --git a/src/api/cocoa/headless.rs b/src/api/cocoa/headless.rs
index 7fe2046..ac6c4e0 100644
--- a/src/api/cocoa/headless.rs
+++ b/src/api/cocoa/headless.rs
@@ -13,6 +13,9 @@ use cocoa::appkit::*;
 use PixelFormat;
 use api::cocoa::helpers;
 
+#[derive(Default)]
+pub struct PlatformSpecificHeadlessBuilderAttributes;
+
 pub struct HeadlessContext {
     width: u32,
     height: u32,
@@ -21,7 +24,9 @@ pub struct HeadlessContext {
 
 impl HeadlessContext {
     pub fn new((width, height): (u32, u32), pf_reqs: &PixelFormatRequirements,
-               opengl: &GlAttributes<&HeadlessContext>) -> Result<HeadlessContext, CreationError>
+               opengl: &GlAttributes<&HeadlessContext>,
+               _: &PlatformSpecificHeadlessBuilderAttributes)
+               -> Result<HeadlessContext, CreationError>
     {
         let context = unsafe {
 
diff --git a/src/api/cocoa/mod.rs b/src/api/cocoa/mod.rs
index d35182e..4502405 100644
--- a/src/api/cocoa/mod.rs
+++ b/src/api/cocoa/mod.rs
@@ -1,7 +1,5 @@
 #![cfg(target_os = "macos")]
 
-pub use self::headless::HeadlessContext;
-
 use {CreationError, Event, MouseCursor, CursorState};
 use CreationError::OsError;
 use libc;
@@ -50,6 +48,8 @@ use events::MouseButton;
 use events;
 
 pub use self::monitor::{MonitorId, get_available_monitors, get_primary_monitor};
+pub use self::headless::HeadlessContext;
+pub use self::headless::PlatformSpecificHeadlessBuilderAttributes;
 
 mod monitor;
 mod event;
@@ -179,6 +179,9 @@ impl Drop for WindowDelegate {
     }
 }
 
+#[derive(Default)]
+pub struct PlatformSpecificWindowBuilderAttributes;
+
 pub struct Window {
     view: IdRef,
     window: IdRef,
@@ -264,7 +267,8 @@ impl<'a> Iterator for WaitEventsIterator<'a> {
 
 impl Window {
     pub fn new(win_attribs: &WindowAttributes, pf_reqs: &PixelFormatRequirements,
-               opengl: &GlAttributes<&Window>) -> Result<Window, CreationError>
+               opengl: &GlAttributes<&Window>, _: &PlatformSpecificWindowBuilderAttributes)
+               -> Result<Window, CreationError>
     {
         if opengl.sharing.is_some() {
             unimplemented!()
diff --git a/src/api/ios/mod.rs b/src/api/ios/mod.rs
index 852d97c..afcc6f4 100644
--- a/src/api/ios/mod.rs
+++ b/src/api/ios/mod.rs
@@ -177,10 +177,14 @@ impl MonitorId {
     }
 }
 
+#[derive(Default)]
+pub struct PlatformSpecificWindowBuilderAttributes;
 
 impl Window {
 
-    pub fn new(builder: &WindowAttributes, _: &PixelFormatRequirements, _: &GlAttributes<&Window>) -> Result<Window, CreationError> {
+    pub fn new(builder: &WindowAttributes, _: &PixelFormatRequirements, _: &GlAttributes<&Window>,
+               _: &PlatformSpecificWindowBuilderAttributes) -> Result<Window, CreationError>
+    {
         unsafe {
             if setjmp(mem::transmute(&mut jmpbuf)) != 0 {
                 let app: id = msg_send![Class::get("UIApplication").unwrap(), sharedApplication];