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std: Redesign c_str and c_vec

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This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.

[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md

The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:

* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
  are now gone. These two methods are replaced with a `CString::from_slice`
  method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
  guarantee that there is a trailing nul byte with no internal nul bytes. This
  means that `CString` now implements `Deref<Target = [c_char]>`, which is where
  it gains most of its methods from. A few helper methods are added to acquire a
  slice of `u8` instead of `c_char`, as well as including a slice with the
  trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
  of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
  functions are now the one method used to convert a `*const c_char` to a Rust
  slice of `u8`.

Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:

[breaking-change]
Closes #20444
This commit is contained in:
Alex Crichton 2014-11-25 13:28:35 -08:00
parent 1f732ef53d
commit ec7a50d20d
59 changed files with 1018 additions and 1998 deletions
Download patch file Download diff file Expand all files Collapse all files

42
src/libcollections/string.rs
View file

@ -320,30 +320,6 @@ impl String {
}
}
/// Creates a `String` from a null-terminated `*const u8` buffer.
///
/// This function is unsafe because we dereference memory until we find the
/// NUL character, which is not guaranteed to be present. Additionally, the
/// slice is not checked to see whether it contains valid UTF-8
#[unstable = "just renamed from `mod raw`"]
pub unsafe fn from_raw_buf(buf: *const u8) -> String {
String::from_str(str::from_c_str(buf as *const i8))
}
/// Creates a `String` from a `*const u8` buffer of the given length.
///
/// This function is unsafe because it blindly assumes the validity of the
/// pointer `buf` for `len` bytes of memory. This function will copy the
/// memory from `buf` into a new allocation (owned by the returned
/// `String`).
///
/// This function is also unsafe because it does not validate that the
/// buffer is valid UTF-8 encoded data.
#[unstable = "just renamed from `mod raw`"]
pub unsafe fn from_raw_buf_len(buf: *const u8, len: uint) -> String {
String::from_utf8_unchecked(Vec::from_raw_buf(buf, len))
}
/// Converts a vector of bytes to a new `String` without checking if
/// it contains valid UTF-8. This is unsafe because it assumes that
/// the UTF-8-ness of the vector has already been validated.
@ -1126,24 +1102,6 @@ mod tests {
String::from_str("\u{FFFD}𐒋\u{FFFD}"));
}
#[test]
fn test_from_buf_len() {
unsafe {
let a = vec![65u8, 65, 65, 65, 65, 65, 65, 0];
assert_eq!(String::from_raw_buf_len(a.as_ptr(), 3), String::from_str("AAA"));
}
}
#[test]
fn test_from_buf() {
unsafe {
let a = vec![65, 65, 65, 65, 65, 65, 65, 0];
let b = a.as_ptr();
let c = String::from_raw_buf(b);
assert_eq!(c, String::from_str("AAAAAAA"));
}
}
#[test]
fn test_push_bytes() {
let mut s = String::from_str("ABC");