版本配套 回退0.7.1

Signed-off-by: ljy9810 <longjianyin@h-partners.com>

.github/workflows/ci.yml

@@ -33,7 +33,6 @@ jobs:
           - 1.36.0  # Oldest supported with MaybeUninit
           - 1.40.0  # Oldest supported with cfg(doctest)
           - 1.51.0  # Oldest supported with ptr::addr_of!
-          - 1.65.0  # Oldest supported with stable const evaluation (sans cell)
           - stable
           - beta
           - nightly

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "memoffset"
-version = "0.8.0"
+version = "0.7.1"
 authors = ["Gilad Naaman <gilad.naaman@gmail.com>"]
 description = "offset_of functionality for Rust structs."
 license = "MIT"

README.OpenSource

@@ -3,7 +3,7 @@
     "Name": "memoffset",
     "License": "Apache License V2.0",
     "License File": "LICENSE",
-    "Version Number": "0.8.0",
+    "Version Number": "0.7.1",
     "Owner": "fangting12@huawei.com",
     "Upstream URL": "https://github.com/Gilnaa/memoffset",
     "Description": "A Rust library that provides support for calculating offsets in memory."

README.md

@@ -7,7 +7,6 @@ C-Like `offset_of` functionality for Rust structs.
 Introduces the following macros:
  * `offset_of!` for obtaining the offset of a member of a struct.
  * `offset_of_tuple!` for obtaining the offset of a member of a tuple. (Requires Rust 1.20+)
- * `offset_of_union!` for obtaining the offset of a member of a union.
  * `span_of!` for obtaining the range that a field, or fields, span.
 
 `memoffset` works under `no_std` environments.
@@ -17,7 +16,7 @@ Add the following dependency to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-memoffset = "0.8"
+memoffset = "0.7"
 ```
 
 These versions will compile fine with rustc versions greater or equal to 1.19.
@@ -46,39 +45,20 @@ fn main() {
 }
 ```
 
-## Usage in constants ##
-`memoffset` has support for compile-time `offset_of!` on rust>=1.65, or on older nightly compilers.
+## Feature flags ##
 
-### Usage on stable Rust ###
-Constant evaluation is automatically enabled and avilable on stable compilers starting with rustc 1.65.
+### Usage in constants ###
+`memoffset` has **experimental** support for compile-time `offset_of!` on a nightly compiler.
 
-This is an incomplete implementation with one caveat:
-Due to dependence on [`#![feature(const_refs_to_cell)]`](https://github.com/rust-lang/rust/issues/80384), you cannot get the offset of a `Cell` field in a const-context.
-
-This means that if need to get the offset of a cell, you'll have to remain on nightly for now.
-
-### Usage on recent nightlies ###
-
-If you're using a new-enough nightly and you require the ability to get the offset of a `Cell`,
-you'll have to enable the `unstable_const` cargo feature, as well as enabling `const_refs_to_cell` in your crate root.
-
-Do note that `unstable_const` is an unstable feature that is set to be removed in a future version of `memoffset`.
+In order to use it, you must enable the `unstable_const` crate feature and several compiler features.
 
 Cargo.toml:
 ```toml
 [dependencies.memoffset]
-version = "0.8"
+version = "0.7"
 features = ["unstable_const"]
 ```
 
-Your crate root: (`lib.rs`/`main.rs`)
-```rust,ignore
-#![feature(const_refs_to_cell)]
-```
-
-### Usage on older nightlies ###
-In order to use it on an older nightly compiler, you must enable the `unstable_const` crate feature and several compiler features.
-
 Your crate root: (`lib.rs`/`main.rs`)
 ```rust,ignore
 #![feature(const_ptr_offset_from, const_refs_to_cell)]

build.rs

@@ -19,7 +19,4 @@ fn main() {
     if ac.probe_rustc_version(1, 51) {
         println!("cargo:rustc-cfg=raw_ref_macros");
     }
-    if ac.probe_rustc_version(1, 65) {
-        println!("cargo:rustc-cfg=stable_const");
-    }
 }

src/lib.rs

@@ -57,10 +57,9 @@
 
 #![no_std]
 #![cfg_attr(
-    all(feature = "unstable_const", not(stable_const)),
-    feature(const_ptr_offset_from)
+    feature = "unstable_const",
+    feature(const_ptr_offset_from, const_refs_to_cell)
 )]
-#![cfg_attr(feature = "unstable_const", feature(const_refs_to_cell))]
 
 #[macro_use]
 #[cfg(doctests)]

src/offset_of.rs

@@ -46,7 +46,7 @@ macro_rules! _memoffset__let_base_ptr {
 }
 
 /// Macro to compute the distance between two pointers.
-#[cfg(any(feature = "unstable_const", stable_const))]
+#[cfg(feature = "unstable_const")]
 #[macro_export]
 #[doc(hidden)]
 macro_rules! _memoffset_offset_from_unsafe {
@@ -58,7 +58,7 @@ macro_rules! _memoffset_offset_from_unsafe {
         unsafe { (field as *const u8).offset_from(base as *const u8) as usize }
     }};
 }
-#[cfg(not(any(feature = "unstable_const", stable_const)))]
+#[cfg(not(feature = "unstable_const"))]
 #[macro_export]
 #[doc(hidden)]
 macro_rules! _memoffset_offset_from_unsafe {
@@ -312,7 +312,7 @@ mod tests {
         assert_eq!(f_ptr as usize + 0, raw_field_union!(f_ptr, Foo, c) as usize);
     }
 
-    #[cfg(any(feature = "unstable_const", stable_const))]
+    #[cfg(feature = "unstable_const")]
     #[test]
     fn const_offset() {
         #[repr(C)]
@@ -337,7 +337,7 @@ mod tests {
         assert_eq!([0; offset_of!(Foo, b)].len(), 4);
     }
 
-    #[cfg(any(feature = "unstable_const", stable_const))]
+    #[cfg(feature = "unstable_const")]
     #[test]
     fn const_fn_offset() {
         const fn test_fn() -> usize {