diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs index c4a92927937a..80d369eb067d 100644 --- a/library/std/src/fs.rs +++ b/library/std/src/fs.rs @@ -260,7 +260,8 @@ pub fn read>(path: P) -> io::Result> { fn inner(path: &Path) -> io::Result> { let mut file = File::open(path)?; let size = file.metadata().map(|m| m.len() as usize).ok(); - let mut bytes = Vec::with_capacity(size.unwrap_or(0)); + let mut bytes = Vec::new(); + bytes.try_reserve_exact(size.unwrap_or(0)).map_err(|_| io::ErrorKind::OutOfMemory)?; io::default_read_to_end(&mut file, &mut bytes, size)?; Ok(bytes) } @@ -302,7 +303,8 @@ pub fn read_to_string>(path: P) -> io::Result { fn inner(path: &Path) -> io::Result { let mut file = File::open(path)?; let size = file.metadata().map(|m| m.len() as usize).ok(); - let mut string = String::with_capacity(size.unwrap_or(0)); + let mut string = String::new(); + string.try_reserve_exact(size.unwrap_or(0)).map_err(|_| io::ErrorKind::OutOfMemory)?; io::default_read_to_string(&mut file, &mut string, size)?; Ok(string) } @@ -774,14 +776,14 @@ impl Read for &File { // Reserves space in the buffer based on the file size when available. fn read_to_end(&mut self, buf: &mut Vec) -> io::Result { let size = buffer_capacity_required(self); - buf.reserve(size.unwrap_or(0)); + buf.try_reserve_exact(size.unwrap_or(0)).map_err(|_| io::ErrorKind::OutOfMemory)?; io::default_read_to_end(self, buf, size) } // Reserves space in the buffer based on the file size when available. fn read_to_string(&mut self, buf: &mut String) -> io::Result { let size = buffer_capacity_required(self); - buf.reserve(size.unwrap_or(0)); + buf.try_reserve_exact(size.unwrap_or(0)).map_err(|_| io::ErrorKind::OutOfMemory)?; io::default_read_to_string(self, buf, size) } }