Does not compile on recent nightly builds

[zesterer]

Hello, when depending on staticvec with default-features = false, I get:

error: `~const` can only be applied to `#[const_trait]` traits
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1420:26
     |
1420 |   where T: Copy + ~const PartialOrd {
     |                          ^^^^^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1455:26
     |
1455 |   where T: Copy + ~const PartialOrd {
     |                          ^^^^^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/utils.rs:177:57
    |
177 | pub(crate) const fn quicksort_internal<T: Copy + ~const PartialOrd>(
    |                                                         ^^^^^^^^^^

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/string_utils.rs:179:7
    |
179 |       $str_var.as_ptr().copy_to_nonoverlapping(dest, $str_len_var);
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
   ::: /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/mod.rs:548:5
    |
548 |     push_str_unchecked_internal!(self, string, old_length, string_length);
    |     --------------------------------------------------------------------- in this macro invocation
    |
    = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable
    = note: this error originates in the macro `push_str_unchecked_internal` (in Nightly builds, run with -Z macro-backtrace for more info)

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/string_utils.rs:163:11
    |
163 | /           $crate::string::string_utils::encode_utf8_raw($char_var, $len)
164 | |             .as_ptr()
165 | |             .copy_to_nonoverlapping($self_var.vec.mut_ptr_at_unchecked(old_length), $len);
    | |_________________________________________________________________________________________^
    |
   ::: /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/mod.rs:649:5
    |
649 |       push_char_unchecked_internal!(self, character as u32, char_len);
    |       --------------------------------------------------------------- in this macro invocation
    |
    = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable
    = note: this error originates in the macro `push_char_unchecked_internal` (in Nightly builds, run with -Z macro-backtrace for more info)

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/string_utils.rs:163:11
    |
163 | /           $crate::string::string_utils::encode_utf8_raw($char_var, $len)
164 | |             .as_ptr()
165 | |             .copy_to_nonoverlapping($self_var.vec.mut_ptr_at_unchecked(old_length), $len);
    | |_________________________________________________________________________________________^
    |
   ::: /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/mod.rs:670:5
    |
670 |       push_char_unchecked_internal!(self, character as u32, char_len);
    |       --------------------------------------------------------------- in this macro invocation
    |
    = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable
    = note: this error originates in the macro `push_char_unchecked_internal` (in Nightly builds, run with -Z macro-backtrace for more info)

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/string_utils.rs:163:11
    |
163 | /           $crate::string::string_utils::encode_utf8_raw($char_var, $len)
164 | |             .as_ptr()
165 | |             .copy_to_nonoverlapping($self_var.vec.mut_ptr_at_unchecked(old_length), $len);
    | |_________________________________________________________________________________________^
    |
   ::: /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/mod.rs:693:9
    |
693 |           push_char_unchecked_internal!(self, character as u32, char_len);
    |           --------------------------------------------------------------- in this macro invocation
    |
    = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable
    = note: this error originates in the macro `push_char_unchecked_internal` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0015]: cannot perform deref coercion on `StaticString<N>` in constant functions
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/mod.rs:720:36
    |
720 |       assert!(str_is_char_boundary(self, new_len));
    |                                    ^^^^
    |
    = note: attempting to deref into `str`
note: deref defined here
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/string_trait_impls.rs:114:3
    |
114 |   type Target = str;
    |   ^^^^^^^^^^^
note: impl defined here, but it is not `const`
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/string/string_trait_impls.rs:113:1
    |
113 | impl<const N: usize> const Deref for StaticString<N> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: add `#![feature(effects)]` to the crate attributes to enable
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:68:1
    |
68  + #![feature(effects)]
    |

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
  --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/utils.rs:80:7
   |
80 |       src.add(i - 1).copy_to_nonoverlapping(dest, 1);
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error[E0015]: cannot call non-const operator in constant functions
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/utils.rs:192:15
    |
192 |         while *values.offset(i) < p {
    |               ^^^^^^^^^^^^^^^^^^^^^
    |
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider further restricting this bound
    |
177 | pub(crate) const fn quicksort_internal<T: Copy + ~const PartialOrd + ~const core::cmp::PartialOrd>(
    |                                                                    ++++++++++++++++++++++++++++++
help: add `#![feature(effects)]` to the crate attributes to enable
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:68:1
    |
68  + #![feature(effects)]
    |

error[E0015]: cannot call non-const operator in constant functions
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/utils.rs:195:15
    |
195 |         while *values.offset(j) > p {
    |               ^^^^^^^^^^^^^^^^^^^^^
    |
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider further restricting this bound
    |
177 | pub(crate) const fn quicksort_internal<T: Copy + ~const PartialOrd + ~const core::cmp::PartialOrd>(
    |                                                                    ++++++++++++++++++++++++++++++
help: add `#![feature(effects)]` to the crate attributes to enable
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:68:1
    |
68  + #![feature(effects)]
    |

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:171:11
    |
171 | /           values
172 | |             .as_ptr()
173 | |             .copy_to_nonoverlapping(Self::first_ptr_mut(&mut data), length);
    | |___________________________________________________________________________^
    |
    = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_to` is not yet stable as a const fn
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:973:7
    |
973 |       self_ptr.offset(1).copy_to(self_ptr, old_length - index - 1);
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_to` is not yet stable as a const fn
   --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:999:7
    |
999 |       self_ptr.offset(1).copy_to(self_ptr, old_length - index - 1);
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_to` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1094:7
     |
1094 |       self_ptr.copy_to(self_ptr.offset(1), old_length - index);
     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_to` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1182:7
     |
1182 |       self_ptr.copy_to(self_ptr.add(values_length), old_length - index);
     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_from_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1183:7
     |
1183 |       self_ptr.copy_from_nonoverlapping(values.as_ptr(), values_length);
     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_to` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1241:9
     |
1241 |         self_ptr.copy_to(self_ptr.add(values_length), old_length - index);
     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_from_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1242:9
     |
1242 |         self_ptr.copy_from_nonoverlapping(values.as_ptr(), values_length);
     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error[E0015]: cannot call non-const fn `<StaticVec<T, N> as Clone>::clone` in constant functions
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1424:19
     |
1424 |       return self.clone();
     |                   ^^^^^^^
     |
     = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: add `#![feature(effects)]` to the crate attributes to enable
     |
68   + #![feature(effects)]
     |

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1429:14
     |
1429 |     unsafe { self.as_ptr().copy_to_nonoverlapping(res_ptr, length) };
     |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1563:7
     |
1563 | /       values
1564 | |         .as_ptr()
1565 | |         .copy_to_nonoverlapping(self.mut_ptr_at_unchecked(old_length), added_length);
     | |____________________________________________________________________________________^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_from_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1628:7
     |
1628 | /       self
1629 | |         .mut_ptr_at_unchecked(old_length)
1630 | |         .copy_from_nonoverlapping(other.as_ptr(), item_count);
     | |_____________________________________________________________^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::mut_ptr::<impl *mut T>::copy_from` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1634:7
     |
1634 | /       other
1635 | |         .as_mut_ptr()
1636 | |         .copy_from(other.ptr_at_unchecked(item_count), other_new_length);
     | |________________________________________________________________________^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1674:7
     |
1674 |       self.as_ptr().copy_to_nonoverlapping(res_ptr, length);
     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:1677:7
     |
1677 | /       other
1678 | |         .as_ptr()
1679 | |         .copy_to_nonoverlapping(res_ptr.add(length), other_length);
     | |__________________________________________________________________^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:2173:9
     |
2173 | /         self
2174 | |           .ptr_at_unchecked(at)
2175 | |           .copy_to_nonoverlapping(Self::first_ptr_mut(&mut split), split_length);
     | |________________________________________________________________________________^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:2217:7
     |
2217 |       self_ptr.copy_to_nonoverlapping(left_ptr, M);
     |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

error: `core::ptr::const_ptr::<impl *const T>::copy_to_nonoverlapping` is not yet stable as a const fn
    --> /home/joshua/.cargo/registry/src/index.crates.io-6f17d22bba15001f/staticvec-0.11.9/src/lib.rs:2218:7
     |
2218 | /       self_ptr
2219 | |         .add(M)
2220 | |         .copy_to_nonoverlapping(right_ptr, right_length);
     | |________________________________________________________^
     |
     = help: add `#![feature(const_intrinsic_copy)]` to the crate attributes to enable

For more information about this error, try `rustc --explain E0015`.
error: could not compile `staticvec` (lib) due to 29 previous errors

[Wasabi375]

I have been looking into porting my fixes over to get this to compile. However I have run into an issue that warrants discussing.

Since the last update to this crate there have been some major changes to how rust handles const traits. Currently all const impls of a trait require the trait to be defined with the #[const_trait] attribute. Otherwise adding a non-const default method to a trait would be a breaking change.
Therefor it is no longer to implement a lot of traits as const, e.g Default, Clone, Borrow, etc.
I expect that this will change again in the future, when the const feature is more stable but AFAICT it is not possible to implement any of those traits as const.

I guess the solution would be to just remove const from all traits and functions. This would mean, that this crate is less powerful but I don't see any way to work around this until rust-lang/rust#67792 advances.

Maybe I missed something. The RFC is currently in a messy state as they are reworking the design. The issue is still for the old design and it is difficult to find good information about the current state and future design.

Apart from the changes to const-traits it is fairly trivial to fix the remaining compilation issues. They are mostly stabilized features and a few new warnings.

[Wasabi375]

I just noticed that this is a duplicate of #59. Maybe @slightlyoutofphase could close one of them and link the other.

[slightlyoutofphase]

Hey @Wasabi375 , I haven't forgotten about this. Really I just kinda don't want to update this in any significant way until nightly syntax at the very least supports the stuff it did when this crate actually worked. I have no particular interest in a "nerfed" version of it, it basically defeats the purpose IMO.

[Wasabi375]

I fully agree with you. I don't think there is a good reason to put a lot of effort into this crate while const traits are in this state.
I guess it would be possible to clean up my fork and release it, but it is in a heavily "nerfed" state as you called it and I don't know if there is anyone else that would be interested in it. I also did add a bunch of modifications that right now are closer to hacks, than anything I am confident in publishing for anyone else to use, so I'm also happy to leave things as they are for now.
I am happy to help update this crate, when we see progress on the rust side or if we see a bunch of people commenting on issues here. Until then there is really not much for us to do.