From f73bb2bfe637b7e0edd8086fe8ba45032d8e3320 Mon Sep 17 00:00:00 2001
From: Birunthan Mohanathas <birunthan@mohanathas.com>
Date: Wed, 24 Jul 2013 22:37:48 +0300
Subject: [PATCH] Implement std::num::Zero for bool Closes #8024.
---
src/libstd/bool.rs | 15 +++++++++++----
src/test/run-pass/deriving-zero.rs | 1 +
2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/src/libstd/bool.rs b/src/libstd/bool.rs
index 126650981cd..eeaea6a2cff 100644
--- a/src/libstd/bool.rs
+++ b/src/libstd/bool.rs
@@ -24,6 +24,7 @@ Implementations of the following traits:
* `Ord`
* `TotalOrd`
* `Eq`
+* `Zero`
## Various functions to compare `bool`s
@@ -36,14 +37,14 @@ Finally, some inquries into the nature of truth: `is_true` and `is_false`.
*/
-#[cfg(not(test))]
-use cmp::{Eq, Ord, TotalOrd, Ordering};
-#[cfg(not(test))]
-use ops::Not;
use option::{None, Option, Some};
use from_str::FromStr;
use to_str::ToStr;
+#[cfg(not(test))] use cmp::{Eq, Ord, TotalOrd, Ordering};
+#[cfg(not(test))] use ops::Not;
+#[cfg(not(test))] use num::Zero;
+
/**
* Negation of a boolean value.
*
@@ -330,6 +331,12 @@ impl Eq for bool {
fn ne(&self, other: &bool) -> bool { (*self) != (*other) }
}
+#[cfg(not(test))]
+impl Zero for bool {
+ fn zero() -> bool { false }
+ fn is_zero(&self) -> bool { *self == false }
+}
+
#[cfg(test)]
mod tests {
use super::*;
diff --git a/src/test/run-pass/deriving-zero.rs b/src/test/run-pass/deriving-zero.rs
index 2ee57624112..f2c5a7e94ef 100644
--- a/src/test/run-pass/deriving-zero.rs
+++ b/src/test/run-pass/deriving-zero.rs
@@ -33,6 +33,7 @@ struct Lots {
g: (f32, char),
h: ~[util::NonCopyable],
i: @mut (int, int),
+ j: bool,
}
fn main() {