plain-0.2.3/.gitignore01006440001750000175000000000036132060311750013025 0ustar0000000000000000/target /Cargo.lock /src/*.bk plain-0.2.3/.travis.yml01006440001750000175000000000066132060311750013151 0ustar0000000000000000language: rust rust: - stable - beta - nightly plain-0.2.3/Cargo.toml.orig01006440001750000175000000000702132060351310013720 0ustar0000000000000000[package] name = "plain" version = "0.2.3" authors = ["jzr"] license = "MIT/Apache-2.0" readme = "README.md" repository = "https://github.com/randomites/plain" homepage = "https://github.com/randomites/plain" documentation = "https://docs.rs/plain" description = "A small Rust library that allows users to reinterpret data of certain types safely." categories = ["no-std", "data-structures", "parsing"] keywords = ["plain", "pod", "ffi", "memory"] plain-0.2.3/Cargo.toml0000644000000017140007161 0ustar00# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO # # When uploading crates to the registry Cargo will automatically # "normalize" Cargo.toml files for maximal compatibility # with all versions of Cargo and also rewrite `path` dependencies # to registry (e.g. crates.io) dependencies # # If you believe there's an error in this file please file an # issue against the rust-lang/cargo repository. If you're # editing this file be aware that the upstream Cargo.toml # will likely look very different (and much more reasonable) [package] name = "plain" version = "0.2.3" authors = ["jzr"] description = "A small Rust library that allows users to reinterpret data of certain types safely." homepage = "https://github.com/randomites/plain" documentation = "https://docs.rs/plain" readme = "README.md" keywords = ["plain", "pod", "ffi", "memory"] categories = ["no-std", "data-structures", "parsing"] license = "MIT/Apache-2.0" repository = "https://github.com/randomites/plain" plain-0.2.3/LICENSE-APACHE01006440001750000175000000025137132060311750012772 0ustar0000000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. 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See the License for the specific language governing permissions and limitations under the License. plain-0.2.3/LICENSE-MIT01006440001750000175000000002046132060311750012474 0ustar0000000000000000Copyright (c) 2017 Plain contributors Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. plain-0.2.3/README.md01006440001750000175000000011157132060311750012322 0ustar0000000000000000# libplain [![Build Status](https://travis-ci.org/randomites/plain.svg?branch=master)](https://travis-ci.org/randomites/plain) [![Current Crates.io Version](https://img.shields.io/crates/v/plain.svg)](https://crates.io/crates/plain) [![Current Documentation](https://docs.rs/plain/badge.svg)](https://docs.rs/plain) A small Rust library that allows users to interpret arrays of bytes as certain kinds of structures safely. This crate provides an unsafe trait [`Plain`](https://docs.rs/plain/0.2.0/plain/trait.Plain.html), which the user of the crate uses to mark types for which operations of this library are safe. See [`Plain`](https://docs.rs/plain/0.2.0/plain/trait.Plain.html) for the contractual obligation. Other than that, everything else in this crate is perfectly safe to use as long as the `Plain` trait is not implemented on inadmissible types (similar to how `Send` and `Sync` in the standard library work). # Purpose In low level systems development, it is sometimes necessary to interpret locations in memory as data structures. Functions of this crate serve to avoid pitfalls associated with that, without having to resort to big, full-featured (de)serialization libraries. On the other hand, this crate contains no provisions when it comes to handling differences in encoding and byte ordering between platforms. As such, it is entirely unsuitable for processing external data such as file contents or network packets. # Examples To start using the crate, simply do `extern crate plain;`. If you want your plain types to have methods from this crate, also include `use plain.Plain;`. Then it's just a matter of marking the right types and using them. ``` extern crate plain; use plain::Plain; use std::mem; #[repr(C)] #[derive(Default)] struct ELF64Header { pub e_ident: [u8; 16], pub e_type: u16, pub e_machine: u16, pub e_version: u32, pub e_entry: u64, pub e_phoff: u64, pub e_shoff: u64, pub e_flags: u32, pub e_ehsize: u16, pub e_phentsize: u16, pub e_phnum: u16, pub e_shentsize: u16, pub e_shnum: u16, pub e_shstrndx: u16, } // SAFE: ELF64Header satisfies all the requirements of `Plain`. unsafe impl Plain for ELF64Header {} impl ELF64Header { fn from_bytes(buf: &[u8]) -> &ELF64Header { plain::from_bytes(buf).expect("The buffer is either too short or not aligned!") } fn from_mut_bytes(buf: &mut [u8]) -> &mut ELF64Header { plain::from_mut_bytes(buf).expect("The buffer is either too short or not aligned!") } fn copy_from_bytes(buf: &[u8]) -> ELF64Header { let mut h = ELF64Header::default(); h.copy_from_bytes(buf).expect("The buffer is too short!"); h } } # fn process_elf(elf: &ELF64Header) {} // Conditional copying for ultimate hackery. fn opportunistic_elf_processing(buf: &[u8]) { if plain::is_aligned::(buf) { // No copy necessary. let elf_ref = ELF64Header::from_bytes(buf); process_elf(elf_ref); } else { // Not aligned properly, copy to stack first. let elf = ELF64Header::copy_from_bytes(buf); process_elf(&elf); } } #[repr(C)] #[derive(Default, Copy, Clone)] struct ArrayEntry { pub name: [u8; 32], pub tag: u32, pub score: u32, } // SAFE: ArrayEntry satisfies all the requirements of `Plain`. unsafe impl Plain for ArrayEntry {} fn array_from_bytes(buf: &[u8]) -> &[ArrayEntry] { // NOTE: length is not a concern here, // since slice_from_bytes() can return empty slice. match plain::slice_from_bytes(buf) { Err(_) => panic!("The buffer is not aligned!"), Ok(arr) => arr, } } fn array_from_unaligned_bytes(buf: &[u8]) -> Vec { let length = buf.len() / mem::size_of::(); let mut result = vec![ArrayEntry::default(); length]; (&mut result).copy_from_bytes(buf).expect("Cannot fail here."); result } # fn main() {} ``` # Comparison to [`pod`](https://crates.io/crates/pod) [`pod`](https://crates.io/crates/pod) is another crate created to help working with plain data. The major difference between `pod` and `plain` is scope. `plain` currently provides only a few functions (+method wrappers) and its implementation involves very few lines of unsafe code. It can be used in `no_std` code. Also, it doesn't deal with [endianness](https://en.wikipedia.org/wiki/Endianness) in any way, so it is only suitable for certain kinds of low-level work. `pod`, on the other hand, provides a wide arsenal of various methods, most of which may be unnecessary for a given use case. It has dependencies on `std` as well as other crates, but among other things it provides tools to handle endianness properly. In short, `plain` is much, much _plainer_... plain-0.2.3/src/error.rs01006440001750000175000000000141132060311750013320 0ustar0000000000000000 #[derive(Debug, Copy, Clone, Eq, PartialEq)] pub enum Error { TooShort, BadAlignment, } plain-0.2.3/src/lib.rs01006440001750000175000000012154132060311750012744 0ustar0000000000000000//! A small Rust library that allows users to interpret arrays of bytes //! as certain kinds of structures safely. //! //! This crate provides an unsafe trait [`Plain`](trait.Plain.html), which the user //! of the crate uses to mark types for which operations of this library are safe. //! See [`Plain`](trait.Plain.html) for the contractual obligation. //! //! Other than that, everything else in this crate is perfectly safe to use as long //! as the `Plain` trait is not implemented on inadmissible types (similar to how //! `Send` and `Sync` in the standard library work). //! //! # Purpose //! //! In low level systems development, it is sometimes necessary to //! interpret locations in memory as data structures. Functions of //! this crate serve to avoid pitfalls associated with that, without //! having to resort to big, full-featured (de)serialization libraries. //! //! On the other hand, this crate contains no provisions when it comes //! to handling differences in encoding and byte ordering between //! platforms. As such, it is entirely unsuitable for processing //! external data such as file contents or network packets. //! //! # Examples //! //! To start using the crate, simply do `extern crate plain;`. //! //! If you want your plain types to have methods from this crate, also include `use plain.Plain;`. //! //! Then it's just a matter of marking the right types and using them. //! //! ``` //! //! extern crate plain; //! use plain::Plain; //! use std::mem; //! //! //! #[repr(C)] //! #[derive(Default)] //! struct ELF64Header { //! pub e_ident: [u8; 16], //! pub e_type: u16, //! pub e_machine: u16, //! pub e_version: u32, //! pub e_entry: u64, //! pub e_phoff: u64, //! pub e_shoff: u64, //! pub e_flags: u32, //! pub e_ehsize: u16, //! pub e_phentsize: u16, //! pub e_phnum: u16, //! pub e_shentsize: u16, //! pub e_shnum: u16, //! pub e_shstrndx: u16, //! } //! //! // SAFE: ELF64Header satisfies all the requirements of `Plain`. //! unsafe impl Plain for ELF64Header {} //! //! impl ELF64Header { //! fn from_bytes(buf: &[u8]) -> &ELF64Header { //! plain::from_bytes(buf).expect("The buffer is either too short or not aligned!") //! } //! //! fn from_mut_bytes(buf: &mut [u8]) -> &mut ELF64Header { //! plain::from_mut_bytes(buf).expect("The buffer is either too short or not aligned!") //! } //! //! fn copy_from_bytes(buf: &[u8]) -> ELF64Header { //! let mut h = ELF64Header::default(); //! h.copy_from_bytes(buf).expect("The buffer is too short!"); //! h //! } //! } //! //! # fn process_elf(elf: &ELF64Header) {} //! //! // Conditional copying for ultimate hackery. //! fn opportunistic_elf_processing(buf: &[u8]) { //! if plain::is_aligned::(buf) { //! // No copy necessary. //! let elf_ref = ELF64Header::from_bytes(buf); //! process_elf(elf_ref); //! } else { //! // Not aligned properly, copy to stack first. //! let elf = ELF64Header::copy_from_bytes(buf); //! process_elf(&elf); //! } //! } //! //! #[repr(C)] //! #[derive(Default, Copy, Clone)] //! struct ArrayEntry { //! pub name: [u8; 32], //! pub tag: u32, //! pub score: u32, //! } //! //! // SAFE: ArrayEntry satisfies all the requirements of `Plain`. //! unsafe impl Plain for ArrayEntry {} //! //! fn array_from_bytes(buf: &[u8]) -> &[ArrayEntry] { //! // NOTE: length is not a concern here, //! // since slice_from_bytes() can return empty slice. //! //! match plain::slice_from_bytes(buf) { //! Err(_) => panic!("The buffer is not aligned!"), //! Ok(arr) => arr, //! } //! } //! //! fn array_from_unaligned_bytes(buf: &[u8]) -> Vec { //! let length = buf.len() / mem::size_of::(); //! let mut result = vec![ArrayEntry::default(); length]; //! (&mut result).copy_from_bytes(buf).expect("Cannot fail here."); //! result //! } //! //! # fn main() {} //! //! ``` //! //! # Comparison to [`pod`](https://crates.io/crates/pod) //! //! [`pod`](https://crates.io/crates/pod) is another crate created to help working with plain data. //! The major difference between `pod` and `plain` is scope. //! //! `plain` currently provides only a few functions (+method wrappers) and its implementation //! involves very few lines of unsafe code. It can be used in `no_std` code. Also, it doesn't //! deal with [endianness](https://en.wikipedia.org/wiki/Endianness) in any way, //! so it is only suitable for certain kinds of low-level work. //! //! `pod`, on the other hand, provides a wide arsenal //! of various methods, most of which may be unnecessary for a given use case. //! It has dependencies on `std` as well as other crates, but among other things //! it provides tools to handle endianness properly. //! //! In short, `plain` is much, much _plainer_... #![no_std] mod error; pub use error::Error; mod plain; pub use plain::Plain; mod methods; pub use methods::{as_bytes, as_mut_bytes, copy_from_bytes, from_bytes, from_mut_bytes, is_aligned, slice_from_bytes, slice_from_bytes_len, slice_from_mut_bytes, slice_from_mut_bytes_len}; #[cfg(test)] #[macro_use] extern crate std; #[cfg(test)] mod tests; plain-0.2.3/src/methods.rs01006440001750000175000000012533132060351120013635 0ustar0000000000000000 use core::{mem, slice}; use {Error, Plain}; /// Check if a byte slice is aligned suitably for type T. #[inline] pub fn is_aligned(bytes: &[u8]) -> bool { ((bytes.as_ptr() as usize) % mem::align_of::()) == 0 } #[inline(always)] fn check_alignment(bytes: &[u8]) -> Result<(), Error> { if is_aligned::(bytes) { Ok(()) } else { Err(Error::BadAlignment) } } #[inline(always)] fn check_length(bytes: &[u8], len: usize) -> Result<(), Error> { if mem::size_of::() > 0 && (bytes.len() / mem::size_of::()) < len { Err(Error::TooShort) } else { Ok(()) } } /// Interpret data as bytes. Not safe for data with padding. #[inline(always)] pub unsafe fn as_bytes(s: &S) -> &[u8] where S: ?Sized, { let bptr = s as *const S as *const u8; let bsize = mem::size_of_val(s); slice::from_raw_parts(bptr, bsize) } /// Interpret data as mutable bytes. /// Reading is not safe for data with padding. Writing is ok. #[inline(always)] pub unsafe fn as_mut_bytes(s: &mut S) -> &mut [u8] where S: Plain + ?Sized, { let bptr = s as *mut S as *mut u8; let bsize = mem::size_of_val(s); slice::from_raw_parts_mut(bptr, bsize) } /// Safely converts a byte slice to a reference. /// /// However, if the byte slice is not long enough /// to contain target type, or if it doesn't /// satisfy the type's alignment requirements, /// the function returns an error. /// /// The function will not fail when the /// byte slice is longer than necessary, since it is /// a common practice to interpret the beginning of /// a slice as a fixed-size header. /// /// In many cases it is preferrable to allocate /// a value/slice of the target type and use /// [`copy_from_bytes()`](fn.copy_from_bytes.html) to copy /// data instead. That way, any issues with alignment /// are implicitly avoided. /// #[inline] pub fn from_bytes(bytes: &[u8]) -> Result<&T, Error> where T: Plain, { try!(check_alignment::(bytes)); try!(check_length::(bytes, 1)); Ok(unsafe { &*(bytes.as_ptr() as *const T) }) } /// Similar to [`from_bytes()`](fn.from_bytes.html), /// except that the output is a slice of T, instead /// of a reference to a single T. All concerns about /// alignment also apply here, but size is handled /// differently. /// /// The result slice's length is set to be /// `bytes.len() / size_of::()`, and there /// are no requirements for input size. I.e. /// the result may be empty slice, and the input /// slice doesn't necessarily have to end on `T`'s /// boundary. The latter has pragmatic reasons: If the /// length of the array is not known in advance, /// e.g. if it's terminated by a special element, /// it's perfectly legal to turn the whole rest /// of data into `&[T]` and set the proper length /// after inspecting the array. /// /// In many cases it is preferrable to allocate /// a value/slice of the target type and use /// [`copy_from_bytes()`](fn.copy_from_bytes.html) to copy /// data instead. That way, any issues with alignment /// are implicitly avoided. /// #[inline] pub fn slice_from_bytes(bytes: &[u8]) -> Result<&[T], Error> where T: Plain, { let len = bytes.len() / mem::size_of::(); slice_from_bytes_len(bytes, len) } /// Same as [`slice_from_bytes()`](fn.slice_from_bytes.html), /// except that it takes explicit length of the result slice. /// /// If the input slice cannot satisfy the length, returns error. /// The input slice is allowed to be longer than necessary. /// #[inline] pub fn slice_from_bytes_len(bytes: &[u8], len: usize) -> Result<&[T], Error> where T: Plain, { try!(check_alignment::(bytes)); try!(check_length::(bytes, len)); Ok(unsafe { slice::from_raw_parts(bytes.as_ptr() as *const T, len) }) } /// See [`from_bytes()`](fn.from_bytes.html). /// /// Does the same, except with mutable references. /// #[inline] pub fn from_mut_bytes(bytes: &mut [u8]) -> Result<&mut T, Error> where T: Plain, { try!(check_alignment::(bytes)); try!(check_length::(bytes, 1)); Ok(unsafe { &mut *(bytes.as_mut_ptr() as *mut T) }) } /// See [`slice_from_bytes()`](fn.slice_from_bytes.html). /// /// Does the same, except with mutable references. /// #[inline] pub fn slice_from_mut_bytes(bytes: &mut [u8]) -> Result<&mut [T], Error> where T: Plain, { let len = bytes.len() / mem::size_of::(); slice_from_mut_bytes_len(bytes, len) } /// See [`slice_from_bytes_len()`](fn.slice_from_bytes_len.html). /// /// Does the same, except with mutable references. /// #[inline] pub fn slice_from_mut_bytes_len(bytes: &mut [u8], len: usize) -> Result<&mut [T], Error> where T: Plain, { try!(check_alignment::(bytes)); try!(check_length::(bytes, len)); Ok(unsafe { slice::from_raw_parts_mut(bytes.as_ptr() as *mut T, len) }) } /// Copies data from a byte slice into existing memory. /// Suitable when [`from_bytes()`](fn.from_bytes.html) would normally /// be used, but the data is not aligned properly in memory. /// /// For an example how to use it, see crate-level documentation. /// #[inline] pub fn copy_from_bytes(into: &mut T, bytes: &[u8]) -> Result<(), Error> where T: Plain + ?Sized, { let sz = mem::size_of_val(into); if bytes.len() < sz { return Err(Error::TooShort); } unsafe { as_mut_bytes(into).copy_from_slice(&bytes[..sz]); } Ok(()) } plain-0.2.3/src/plain.rs01006440001750000175000000004761132060311750013306 0ustar0000000000000000use Error; /// A trait for plain data types that can be safely read from a byte slice. /// /// A type can be [`Plain`](trait.Plain.html) if it is `#repr(C)` and only contains /// data with no possible invalid values. Types that _can't_ be `Plain` /// include, but are not limited to, `bool`, `char`, `enum`s, tuples, /// pointers and references. /// /// At this moment, `Drop` types are also not legal, because /// compiler adds a special "drop flag" into the type. This is slated /// to change in the future. /// /// On the other hand, arrays of a `Plain` type, and /// structures where all members are plain (and not `Drop`), are okay. /// /// Structures that are not `#repr(C)`, while not necessarily illegal /// in principle, are largely useless because they don't have a stable /// layout. For example, the compiler is allowed to reorder fields /// arbitrarily. /// /// All methods of this trait are implemented automatically as wrappers /// for crate-level funtions. /// pub unsafe trait Plain { #[inline(always)] fn from_bytes(bytes: &[u8]) -> Result<&Self, Error> where Self: Sized, { ::from_bytes(bytes) } #[inline(always)] fn slice_from_bytes(bytes: &[u8]) -> Result<&[Self], Error> where Self: Sized, { ::slice_from_bytes(bytes) } #[inline(always)] fn slice_from_bytes_len(bytes: &[u8], len: usize) -> Result<&[Self], Error> where Self: Sized, { ::slice_from_bytes_len(bytes, len) } #[inline(always)] fn from_mut_bytes(bytes: &mut [u8]) -> Result<&mut Self, Error> where Self: Sized, { ::from_mut_bytes(bytes) } #[inline(always)] fn slice_from_mut_bytes(bytes: &mut [u8]) -> Result<&mut [Self], Error> where Self: Sized, { ::slice_from_mut_bytes(bytes) } #[inline(always)] fn slice_from_mut_bytes_len(bytes: &mut [u8], len: usize) -> Result<&mut [Self], Error> where Self: Sized, { ::slice_from_mut_bytes_len(bytes, len) } #[inline(always)] fn copy_from_bytes(&mut self, bytes: &[u8]) -> Result<(), Error> { ::copy_from_bytes(self, bytes) } } unsafe impl Plain for u8 {} unsafe impl Plain for u16 {} unsafe impl Plain for u32 {} unsafe impl Plain for u64 {} unsafe impl Plain for usize {} unsafe impl Plain for i8 {} unsafe impl Plain for i16 {} unsafe impl Plain for i32 {} unsafe impl Plain for i64 {} unsafe impl Plain for isize {} unsafe impl Plain for [S] where S: Plain, { } plain-0.2.3/src/tests.rs01006440001750000175000000005344132060311750013343 0ustar0000000000000000 #![allow(dead_code)] use ::*; use core::mem; #[repr(C)] #[derive(Debug, Default, Copy, Eq, Clone, PartialEq)] struct Dummy1 { field1: u64, field2: u32, field3: u16, field4: u8, field5: u8, } unsafe impl Plain for Dummy1 {} #[repr(C)] #[derive(Debug, Default, Copy, Eq, Clone, PartialEq)] struct Dummy2 { field1: u8, field2: u8, field3: u16, field4: u32, field5: u64, } unsafe impl Plain for Dummy2 {} fn as_bytes(r: &T) -> &[u8] { unsafe { methods::as_bytes(r) } } fn as_mut_bytes(r: &mut T) -> &mut [u8] { unsafe { methods::as_mut_bytes(r) } } #[test] fn one_too_short() { let b = vec![0u8; mem::size_of::() - 1]; let r = Dummy1::from_bytes(&b); assert!(r == Err(Error::TooShort)); } #[test] fn unaligned() { let b = vec![0u8; mem::size_of::() + 1]; let b = &b[1..]; let r = Dummy1::from_bytes(&b); assert!(r == Err(Error::BadAlignment)); } #[test] fn copy_test() { let t1 = Dummy1 { field1: 0xaaaaaaaaaaaaaaaau64, field2: 0xbbbbbbbbu32, field3: 0xccccu16, field4: 0xddu8, field5: 0xeeu8, }; let mut t2 = Dummy2::default(); assert!(t2.copy_from_bytes(as_bytes(&t1)) == Ok(())); assert!(t2.field1 == 0xaau8); assert!(t2.field2 == 0xaau8); assert!(t2.field3 == 0xaaaau16); assert!(t2.field4 == 0xaaaaaaaau32); assert!(t2.field5 == 0xbbbbbbbbccccddeeu64 || t2.field5 == 0xeeddccccbbbbbbbbu64); let sz = mem::size_of::(); assert!(t2.copy_from_bytes(&as_bytes(&t1)[..sz - 1]) == Err(Error::TooShort)); } #[test] fn basic_function() { let t1 = Dummy1 { field1: 0xaaaaaaaaaaaaaaaau64, field2: 0xbbbbbbbbu32, field3: 0xccccu16, field4: 0xddu8, field5: 0xeeu8, }; let r1: &Dummy2 = from_bytes(as_bytes(&t1)).unwrap(); assert!(r1.field1 == 0xaau8); assert!(r1.field2 == 0xaau8); assert!(r1.field3 == 0xaaaau16); assert!(r1.field4 == 0xaaaaaaaau32); assert!(r1.field5 == 0xbbbbbbbbccccddeeu64 || r1.field5 == 0xeeddccccbbbbbbbbu64); let r2 = as_bytes(r1); assert!(r2.len() == mem::size_of::()); assert!(r2[5] == 0xaa); let size = r2.len(); let r3 = as_bytes(r2); assert!(r3.len() == size); let r4 = Dummy1::from_bytes(r3).unwrap(); let r5 = from_bytes::(as_bytes(r4)).unwrap(); { let r6 = slice_from_bytes::(as_bytes(r5)).unwrap(); assert!(r6.len() == 1); assert!(t1 == r6[0]); } let r7 = slice_from_bytes::(as_bytes(r5)).unwrap(); assert!(r7.len() == 2); assert!(r7[0] == 0xaaaaaaaaaaaaaaaau64); assert!(r7[1] == 0xbbbbbbbbccccddeeu64 || r7[1] == 0xeeddccccbbbbbbbbu64); }