Implement Sum/Product

Author: termoshtt

src/lib.rs

@@ -25,9 +25,10 @@ use std::fmt;
 #[cfg(test)]
 use std::hash;
 use std::ops::{Add, Div, Mul, Neg, Sub, Rem};
+use std::iter::{Sum, Product};
 use std::str::FromStr;
 
-use traits::{Zero, One, Num, Float};
+use traits::{Zero, One, Num, NumAssign, Float};
 
 // FIXME #1284: handle complex NaN & infinity etc. This
 // probably doesn't map to C's _Complex correctly.
@@ -1046,6 +1047,46 @@ impl<T: Num + Clone> Num for Complex<T> {
     }
 }
 
+impl<T: Clone + NumAssign> Sum for Complex<T> {
+    fn sum<I>(iter: I) -> Self where I: Iterator<Item = Self> {
+        let mut s = Self::zero();
+        for c in iter {
+            s += c;
+        }
+        s
+    }
+}
+
+impl<'a, T: 'a + Clone + NumAssign> Sum<&'a Complex<T>> for Complex<T> {
+    fn sum<I>(iter: I) -> Self where I: Iterator<Item = &'a Complex<T>> {
+        let mut s = Self::zero();
+        for c in iter {
+            s += c;
+        }
+        s
+    }
+}
+
+impl<T: Clone + NumAssign> Product for Complex<T> {
+    fn product<I>(iter: I) -> Self where I: Iterator<Item = Self> {
+        let mut s = Self::one();
+        for c in iter {
+            s *= c;
+        }
+        s
+    }
+}
+
+impl<'a, T: 'a + Clone + NumAssign> Product<&'a Complex<T>> for Complex<T> {
+    fn product<I>(iter: I) -> Self where I: Iterator<Item = &'a Complex<T>> {
+        let mut s = Self::one();
+        for c in iter {
+            s *= c;
+        }
+        s
+    }
+}
+
 #[cfg(feature = "serde")]
 impl<T> serde::Serialize for Complex<T>
     where T: serde::Serialize