Add CreationError::RobustnessNotSupported

src/api/cocoa/mod.rs

@@ -335,7 +335,7 @@ impl Window {
 
         match builder.gl_robustness {
             Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                return Err(CreationError::NotSupported);
+                return Err(CreationError::RobustnessNotSupported);
             },
             _ => ()
         }

src/api/egl/mod.rs

@@ -434,7 +434,7 @@ unsafe fn create_context(egl: &ffi::egl::Egl, display: ffi::egl::types::EGLDispl
                     context_attributes.push(ffi::egl::NO_RESET_NOTIFICATION as libc::c_int);
                     flags = flags | ffi::egl::CONTEXT_OPENGL_ROBUST_ACCESS as libc::c_int;
                 } else {
-                    return Err(CreationError::NotSupported);
+                    return Err(CreationError::RobustnessNotSupported);
                 }
             },
 
@@ -454,7 +454,7 @@ unsafe fn create_context(egl: &ffi::egl::Egl, display: ffi::egl::types::EGLDispl
                     context_attributes.push(ffi::egl::LOSE_CONTEXT_ON_RESET as libc::c_int);
                     flags = flags | ffi::egl::CONTEXT_OPENGL_ROBUST_ACCESS as libc::c_int;
                 } else {
-                    return Err(CreationError::NotSupported);
+                    return Err(CreationError::RobustnessNotSupported);
                 }
             },
 
@@ -488,7 +488,7 @@ unsafe fn create_context(egl: &ffi::egl::Egl, display: ffi::egl::types::EGLDispl
         // robustness is not supported
         match gl_robustness {
             Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                return Err(CreationError::NotSupported);
+                return Err(CreationError::RobustnessNotSupported);
             },
             _ => ()
         }

src/api/glx/mod.rs

@@ -301,7 +301,7 @@ fn create_context(glx: &ffi::glx::Glx, extra_functions: &ffi::glx_extra::Glx, ex
                 } else {
                     match robustness {
                         Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                            return Err(CreationError::NotSupported);
+                            return Err(CreationError::RobustnessNotSupported);
                         },
                         _ => ()
                     }

src/api/osmesa/mod.rs

@@ -41,7 +41,7 @@ impl OsMesaContext {
 
         match builder.gl_robustness {
             Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                return Err(CreationError::NotSupported.into());
+                return Err(CreationError::RobustnessNotSupported.into());
             },
             _ => ()
         }

src/api/wgl/mod.rs

@@ -290,7 +290,7 @@ unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'st
                 } else {
                     match builder.gl_robustness {
                         Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                            return Err(CreationError::NotSupported);
+                            return Err(CreationError::RobustnessNotSupported);
                         },
                         _ => ()
                     }

src/lib.rs

@@ -109,6 +109,7 @@ pub trait GlContext {
 pub enum CreationError {
     OsError(String),
     NotSupported,
+    RobustnessNotSupported,
 }
 
 impl CreationError {
@@ -116,6 +117,8 @@ impl CreationError {
         match *self {
             CreationError::OsError(ref text) => &text,
             CreationError::NotSupported => "Some of the requested attributes are not supported",
+            CreationError::RobustnessNotSupported => "Your requested robustness, but it is \
+                                                      not supported.",
         }
     }
 }