Auto merge of #76 - autumnai:docs/cuda_examples, r=hobofan

docs/readme: clarify CUDA requirement for examples

README.md

@@ -99,6 +99,7 @@ networks (e.g. Alexnet, Overfeat, VGG). To run them on your machine, just follow
 the install guide, clone this repoistory and then run
 
 ```bash
+# The examples currently require CUDA support.
 cargo run --release --example benchmarks
 ```
 
@@ -132,8 +133,7 @@ Want to contribute? Awesome! We have [instructions to help you get started][cont
 Leaf has a near real-time collaboration culture and happens here on Github and
 on the [Leaf Gitter Channel][gitter-leaf].
 
-Unless you explicitly state otherwise, any contribution intentionally
-submitted for inclusion in the work by you, as defined in the Apache-2.0
+Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0
 license, shall be dual licensed as below, without any additional terms or
 conditions.
 

examples/benchmarks.rs

@@ -113,7 +113,10 @@ fn get_time_scale<'a>(sec: f64) -> (f64, &'a str) {
 }
 
 #[cfg(not(feature = "cuda"))]
-fn bench_alexnet() {}
+fn bench_alexnet() {
+    println!("Examples run only with CUDA support at the moment, because of missing native convolution implementation for the Collenchyma NN Plugin.");
+    println!("Try compiling with the \"cuda\" feature flag.");
+}
 #[cfg(feature = "cuda")]
 fn bench_alexnet() {
     let mut cfg = SequentialConfig::default();
@@ -194,6 +197,7 @@ fn bench_alexnet() {
 #[cfg(not(feature = "cuda"))]
 fn bench_overfeat() {
     println!("Examples run only with CUDA support at the moment, because of missing native convolution implementation for the Collenchyma NN Plugin.");
+    println!("Try compiling with the \"cuda\" feature flag.");
 }
 #[cfg(feature = "cuda")]
 fn bench_overfeat() {
@@ -275,6 +279,7 @@ fn bench_overfeat() {
 #[cfg(not(feature = "cuda"))]
 fn bench_vgg_a() {
     println!("Examples run only with CUDA support at the moment, because of missing native convolution implementation for the Collenchyma NN Plugin.");
+    println!("Try compiling with the \"cuda\" feature flag.");
 }
 #[cfg(feature = "cuda")]
 fn bench_vgg_a() {