impl FromIterator and From for Map

src/from.rs

@@ -0,0 +1,83 @@
+// Copyright (c) 2023 Yegor Bugayenko
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+use crate::Map;
+
+impl<K: Copy + PartialEq, V: Copy, const N: usize> FromIterator<(K, V)> for Map<K, V, N> {
+    #[inline]
+    fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> Self {
+        let mut m: Map<K, V, N> = Map::new();
+        for (k, v) in iter {
+            m.insert(k, v);
+        }
+        return m;
+    }
+}
+
+impl<K: Copy + PartialEq, V: Copy, const N: usize> From<[(K, V); N]> for Map<K, V, N> {
+    #[inline]
+    fn from(arr: [(K, V); N]) -> Self {
+        Self::from_iter(arr)
+    }
+}
+
+#[cfg(test)]
+use anyhow::Result;
+
+#[cfg(test)]
+const TEST_ARRAY: [(i32, &str); 5] = [(1, "sun"), (2, "mon"), (3, "tue"), (4, "wed"), (5, "thu")];
+
+#[test]
+fn from_iter() -> Result<()> {
+    let vec = Vec::from(TEST_ARRAY);
+    let m: Map<i32, &str, 10> = Map::from_iter(vec);
+    assert_eq!(m.len(), 5);
+    Ok(())
+}
+
+#[test]
+#[should_panic]
+fn from_larger_iter() {
+    let vec = Vec::from(TEST_ARRAY);
+    let _m: Map<i32, &str, 1> = Map::from_iter(vec);
+}
+
+#[test]
+fn from_array() -> Result<()> {
+    let m = Map::from(TEST_ARRAY);
+    assert_eq!(m.len(), 5);
+    Ok(())
+}
+
+#[test]
+fn array_into_map() -> Result<()> {
+    let m: Map<i32, &str, 5> = TEST_ARRAY.into();
+    assert_eq!(m.len(), 5);
+    Ok(())
+}
+
+#[test]
+fn from_with_duplicates() -> Result<()> {
+    let arr = [(1, "sun"), (2, "mon"), (3, "tue"), (1, "wed"), (2, "thu")];
+    let m = Map::from(arr);
+    assert_eq!(m.len(), 3);
+    assert_eq!(m[&2], "thu");
+    Ok(())
+}

src/lib.rs

@@ -48,6 +48,7 @@
 mod ctors;
 mod debug;
 mod eq;
+mod from;
 mod index;
 mod iterators;
 mod map;