Added FromIterator

Added a from iterator, and added a test case.

Author: CGMossa

soa-derive-internal/src/iter.rs

@@ -202,6 +202,19 @@ pub fn derive(input: &Input) -> TokenStream {
                 }
             }
 
+
+            impl<'a> std::iter::FromIterator<&'a #name> for #vec_name {
+                fn from_iter<T: IntoIterator<Item=&'a #name>>(iter: T) -> Self {
+                    let mut result = #vec_name::new();
+                    for element in iter {
+                        #(
+                            (result.#fields_names).push(element.#fields_names.clone());
+                        )*
+                    }
+                    result
+                }
+            }
+
             impl<'a, 'b> IntoIterator for &'a #slice_name<'b> {
                 type Item = #ref_name<'a>;
                 type IntoIter = #detail_mod::Iter<'a>;

tests/iter.rs

@@ -50,3 +50,20 @@ fn iter_mut() {
     assert_eq!(particles.mass[1], 2.0);
     assert_eq!(particles.mass[2], 2.0);
 }
+
+#[test]
+fn from_iter() {
+    let mut vec_with_particles = Vec::new();
+    vec_with_particles.push(Particle::new(String::from("Na"), 0.0));
+    vec_with_particles.push(Particle::new(String::from("Cl"), 0.0));
+    vec_with_particles.push(Particle::new(String::from("Zn"), 0.0));
+
+    let particles_from_iter: ParticleVec = vec_with_particles.iter().collect();
+
+    let mut particles = ParticleVec::new();
+    particles.push(Particle::new(String::from("Na"), 0.0));
+    particles.push(Particle::new(String::from("Cl"), 0.0));
+    particles.push(Particle::new(String::from("Zn"), 0.0));
+
+    assert_eq!(particles, particles_from_iter)
+}