diff options
| -rw-r--r-- | src/libstd/fs.rs | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs index 479e4d08f4b..7bd1adc411a 100644 --- a/src/libstd/fs.rs +++ b/src/libstd/fs.rs @@ -231,7 +231,9 @@ fn initial_buffer_size(file: &File) -> usize { /// Read the entire contents of a file into a bytes vector. /// /// This is a convenience function for using [`File::open`] and [`read_to_end`] -/// with fewer imports and without an intermediate variable. +/// with fewer imports and without an intermediate variable. It pre-allocates a +/// buffer based on the file size when available, so it is generally faster than +/// reading into a vector created with `Vec::new()`. /// /// [`File::open`]: struct.File.html#method.open /// [`read_to_end`]: ../io/trait.Read.html#method.read_to_end @@ -270,7 +272,9 @@ pub fn read<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> { /// Read the entire contents of a file into a string. /// /// This is a convenience function for using [`File::open`] and [`read_to_string`] -/// with fewer imports and without an intermediate variable. +/// with fewer imports and without an intermediate variable. It pre-allocates a +/// buffer based on the file size when available, so it is generally faster than +/// reading into a string created with `String::new()`. /// /// [`File::open`]: struct.File.html#method.open /// [`read_to_string`]: ../io/trait.Read.html#method.read_to_string |