Add trait implementations for Vec<T>, [T], Option<T>

maud/src/lib.rs

@@ -11,7 +11,7 @@
 
 extern crate alloc;
 
-use alloc::{borrow::Cow, boxed::Box, string::String, sync::Arc};
+use alloc::{borrow::Cow, boxed::Box, string::String, sync::Arc, vec::Vec};
 use core::fmt::{self, Arguments, Display, Write};
 
 pub use maud_macros::html;
@@ -156,6 +156,30 @@ impl<T: Render + ?Sized> Render for Arc<T> {
     }
 }
 
+impl<T: Render> Render for Vec<T> {
+    fn render_to(&self, w: &mut String) {
+        for item in self {
+            item.render_to(w);
+        }
+    }
+}
+
+impl<T: Render> Render for [T] {
+    fn render_to(&self, w: &mut String) {
+        for item in self {
+            item.render_to(w);
+        }
+    }
+}
+
+impl<T: Render> Render for Option<T> {
+    fn render_to(&self, w: &mut String) {
+        if let Some(ref value) = *self {
+            value.render_to(w);
+        }
+    }
+}
+
 macro_rules! impl_render_with_display {
     ($($ty:ty)*) => {
         $(

maud/tests/misc.rs

@@ -1,4 +1,4 @@
-use maud::html;
+use maud::{html, Render};
 
 #[test]
 fn issue_13() {
@@ -143,3 +143,35 @@ fn render_arc() {
     let arc = std::sync::Arc::new("foo");
     assert_eq!(html! { (arc) }.into_string(), "foo");
 }
+
+#[test]
+fn render_vec_generics() {
+    let vec = vec![1, 2, 3];
+    assert_eq!(vec.render().into_string(), "123");
+    let vec = vec!["a", "b", "c"];
+    assert_eq!(vec.render().into_string(), "abc");
+    let vec = vec![String::from("a"), String::from("b"), String::from("c")];
+    assert_eq!(vec.render().into_string(), "abc");
+}
+
+#[test]
+fn render_slice_generics() {
+    let slice = &[1, 2, 3];
+    assert_eq!(slice.render().into_string(), "123");
+    let slice = &["a", "b", "c"];
+    assert_eq!(slice.render().into_string(), "abc");
+    let slice = &[String::from("a"), String::from("b"), String::from("c")];
+    assert_eq!(slice.render().into_string(), "abc");
+}
+
+#[test]
+fn render_option_generics() {
+    let option = Some(42);
+    assert_eq!(option.render().into_string(), "42");
+    let option = Some("foo");
+    assert_eq!(option.render().into_string(), "foo");
+    let option = Some(String::from("bar"));
+    assert_eq!(option.render().into_string(), "bar");
+    let option: Option<String> = None;
+    assert_eq!(option.render().into_string(), "");
+}