Add Capacity/length methods for OsString.

https://github.com/rust-lang/rust/issues/29453

1 files changed, 14 insertions, 0 deletions

diff --git a/src/libstd/sys/common/wtf8.rs b/src/libstd/sys/common/wtf8.rs
index bc997af3a27..68ba2fe20b4 100644
--- a/src/libstd/sys/common/wtf8.rs
+++ b/src/libstd/sys/common/wtf8.rs
@@ -178,6 +178,10 @@ impl Wtf8Buf {
         Wtf8Buf { bytes: <[_]>::to_vec(str.as_bytes()) }
     }
 
+    pub fn clear(&mut self) {
+        self.bytes.clear()
+    }
+
     /// Creates a WTF-8 string from a potentially ill-formed UTF-16 slice of 16-bit code units.
     ///
     /// This is lossless: calling `.encode_wide()` on the resulting string
@@ -234,6 +238,11 @@ impl Wtf8Buf {
         self.bytes.reserve(additional)
     }
 
+    #[inline]
+    pub fn reserve_exact(&mut self, additional: usize) {
+        self.bytes.reserve_exact(additional)
+    }
+
     /// Returns the number of bytes that this string buffer can hold without reallocating.
     #[inline]
     pub fn capacity(&self) -> usize {
@@ -443,6 +452,11 @@ impl Wtf8 {
         self.bytes.len()
     }
 
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.bytes.is_empty()
+    }
+
     /// Returns the code point at `position` if it is in the ASCII range,
     /// or `b'\xFF' otherwise.
     ///