add "simd" test with nightly-2019-01-01 toolchain and get it working

.travis.yml

@@ -17,6 +17,9 @@ matrix:
       env: CARGO_FEATURES="simd"
     - rust: nightly
       env: CARGO_FEATURES="serde simd"
+    - rust: nightly-2019-01-01
+      # an old nightly build where "simd" still worked and "specialization"
+      env: CARGO_FEATURES="simd"
   allow_failures:
     - rust: nightly
 

Cargo.toml

@@ -26,8 +26,8 @@ mint = { version = "0.5", optional = true }
 num-traits = "0.2"
 rand = { version = "0.7", optional = true }
 serde = { version = "1.0", features = ["serde_derive"], optional = true }
-simd = { version = "0.2", optional = true }
+simd = { version = "0.2", optional = true }  # works only in rust toolchain up to 1.32
 
 [dev-dependencies]
-glium = "0.23"
+# glium = "0.23"  # causes problems with nightly-2019-01-01 needed for testing "simd"
 serde_json = "1.0"

src/conv.rs

@@ -4,6 +4,7 @@
 //! For example, when declaring `glium` uniforms, we need to convert to fixed
 //! length arrays. We can use the `Into` trait directly, but it is rather ugly!
 //!
+//! --- Doc-test disabled because glium causes problems with nightly-2019-01-01 needed for "simd"
 //! ` ` `rust
 //! #[macro_use]
 //! extern crate glium;
@@ -26,6 +27,7 @@
 //!
 //! Instead, we can use the conversion functions from the `conv` module:
 //!
+//! --- Doc-test disabled because glium causes problems nightly-2019-01-01 needed for "simd"
 //! ` ` `rust
 //! #[macro_use]
 //! extern crate glium;

src/macros.rs

@@ -17,12 +17,12 @@
 
 #![macro_use]
 
-#[cfg(feature = "specialization")]
+#[cfg(feature = "simd")]
 macro_rules! default_fn {
     { $($tt:tt)* } => { default fn $( $tt )* };
 }
 
-#[cfg(not(feature = "specialization"))]
+#[cfg(not(feature = "simd"))]
 macro_rules! default_fn {
     { $($tt:tt)* } => { fn $( $tt )* };
 }

src/quaternion_simd.rs

@@ -13,6 +13,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use quaternion::*;
+
+use structure::*;
+
+use std::mem;
+use std::ops::*;
+
 use simd::f32x4 as Simdf32x4;
 
 impl From<Simdf32x4> for Quaternion<f32> {

src/vector_simd.rs

@@ -13,6 +13,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use vector::*;
+
+use structure::*;
+
+use std::mem;
+use std::ops::*;
+
 use simd::f32x4 as Simdf32x4;
 use simd::i32x4 as Simdi32x4;
 use simd::u32x4 as Simdu32x4;