Rollup merge of #73529 - pickfire:liballoc-specfromelem-i8, r=cuviper

[rust.git] / src / liballoc / vec.rs

diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 1265d0e56b576ceed08c1f12091a4abd8053b043..c2cf64393adf8db1a1b62438629a9eac8521a920 100644 (file)
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -1801,6 +1801,21 @@ impl<T: Clone> SpecFromElem for T {
     }
 }
 
+impl SpecFromElem for i8 {
+    #[inline]
+    fn from_elem(elem: i8, n: usize) -> Vec<i8> {
+        if elem == 0 {
+            return Vec { buf: RawVec::with_capacity_zeroed(n), len: n };
+        }
+        unsafe {
+            let mut v = Vec::with_capacity(n);
+            ptr::write_bytes(v.as_mut_ptr(), elem as u8, n);
+            v.set_len(n);
+            v
+        }
+    }
+}
+
 impl SpecFromElem for u8 {
     #[inline]
     fn from_elem(elem: u8, n: usize) -> Vec<u8> {
@@ -1845,7 +1860,6 @@ fn is_zero(&self) -> bool {
     };
 }
 
-impl_is_zero!(i8, |x| x == 0);
 impl_is_zero!(i16, |x| x == 0);
 impl_is_zero!(i32, |x| x == 0);
 impl_is_zero!(i64, |x| x == 0);