Stabilize remaining integer methods as const fn

[jhpratt]

This pull request stabilizes the following methods as const fn:

• i*::checked_div
• i*::checked_div_euclid
• i*::checked_rem
• i*::checked_rem_euclid
• i*::div_euclid
• i*::overflowing_div
• i*::overflowing_div_euclid
• i*::overflowing_rem
• i*::overflowing_rem_euclid
• i*::rem_euclid
• i*::wrapping_div
• i*::wrapping_div_euclid
• i*::wrapping_rem
• i*::wrapping_rem_euclid
• u*::checked_div
• u*::checked_div_euclid
• u*::checked_rem
• u*::checked_rem_euclid
• u*::div_euclid
• u*::overflowing_div
• u*::overflowing_div_euclid
• u*::overflowing_rem
• u*::overflowing_rem_euclid
• u*::rem_euclid
• u*::wrapping_div
• u*::wrapping_div_euclid
• u*::wrapping_rem
• u*::wrapping_rem_euclid

These can all be implemented on the current stable (1.49). There are two unstable details: const likely/unlikely and unchecked division/remainder. Both of these are for optimizations, and are in no way required to make the methods function; there is no exposure of these details publicly. Per comments below, it seems best practice is to stabilize the intrinsics. As such, intrinsics::unchecked_div and intrinsics::unchecked_rem have been stabilized as const as part of this pull request as well. The methods themselves remain unstable.

I believe part of the reason these were not stabilized previously was the behavior around division by 0 and modulo 0. After testing on nightly, the diagnostic for something like const _: i8 = 5i8 % 0i8; is similar to that of const _: i8 = 5i8.rem_euclid(0i8); (assuming the appropriate feature flag is enabled). As such, I believe these methods are ready to be stabilized as const fn.

This pull request represents the final methods mentioned in #53718. As such, this PR closes #53718.

@rustbot modify labels to +A-const-fn, +T-libs

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r? @m-ou-se

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[rust-log-analyzer]

The job mingw-check failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   Compiling libc v0.2.79
   Compiling std v0.0.0 (/checkout/library/std)
   Compiling compiler_builtins v0.1.39
   Compiling unwind v0.0.0 (/checkout/library/unwind)
error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
525  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /      int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |      "[0x12]", "[0x12]", "", "" }
     | |_________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
525  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /      int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |      "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_______________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
525  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /      int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |      "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |      "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |_________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
525  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /      int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |      "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |      "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |_________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
525  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:118:5
     |
     |
118  | /      int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
119  | |      170141183460469231731687303715884105727, 16,
120  | |      "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
121  | |      "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
...    |
124  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
125  | |        0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
     | |_________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
525  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:148:5
     |
     |
148  | /      int_impl! { isize, i64, usize, 64, -9223372036854775808, 9223372036854775807,
149  | |      12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
150  | |       "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
151  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
152  | |       usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
     | |________________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
577  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /      int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |      "[0x12]", "[0x12]", "", "" }
     | |_________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
577  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /      int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |      "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_______________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
577  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /      int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |      "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |      "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |_________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
577  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /      int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |      "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |      "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |_________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
577  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:118:5
     |
     |
118  | /      int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
119  | |      170141183460469231731687303715884105727, 16,
120  | |      "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
121  | |      "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
...    |
124  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
125  | |        0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
     | |_________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
577  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2007 |  |     }
2008 |  | }
2008 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:148:5
     |
     |
148  | /      int_impl! { isize, i64, usize, 64, -9223372036854775808, 9223372036854775807,
149  | |      12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
150  | |       "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
151  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
152  | |       usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
     | |________________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:535:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
535  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:157:5
     |
     |
157  | /      uint_impl! { u8, u8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
158  | |      "[0x12]", "", "" }
     | |_______________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:535:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
535  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:656:5
     |
     |
656  | /      uint_impl! { u16, u16, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
657  | |      "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_____________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:535:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
535  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:662:5
     |
     |
662  | /      uint_impl! { u32, u32, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
663  | |      "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |_________________________________________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:535:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
535  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:668:5
     |
     |
668  | /      uint_impl! { u64, u64, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
669  | |      "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
670  | |      "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
671  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
672  | |      "", ""}
     | |____________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_div` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:535:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
535  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:677:5
     |
     |
677  | /      uint_impl! { u128, u128, 128, 340282366920938463463374607431768211455, 16,
678  | |      "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
679  | |      "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
680  | |      "[0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, \
683  | |        0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]",
684  | |       "", ""}
     | |_____________- in this macro invocation
     |
     |
     = help: Const-stable functions can only call other const-stable functions

error: `intrinsics::unchecked_div` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:535:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
535  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:705:5
     |
     |
705  | /      uint_impl! { usize, u64, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
706  | |      "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
707  | |      "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
708  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
709  | |      usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
     | |_______________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:586:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
586  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:157:5
     |
     |
157  | /      uint_impl! { u8, u8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
158  | |      "[0x12]", "", "" }
     | |_______________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:586:31
     |
1    |  / macro_rules! uint_impl {
2    |  |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |  |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
586  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1833 |  |     }
1834 |  | }
1834 |  | }
     |  |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:656:5
     |
     |
656  | /      uint_impl! { u16, u16, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
657  | |      "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_____________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `intrinsics::unchecked_rem` is not yet stable as a const fn
    --> library/core/src/num/uint_macros.rs:586:31
     |

[rust-log-analyzer]

The job mingw-check failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   Compiling unwind v0.0.0 (/checkout/library/unwind)
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:517:9
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
517  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
521  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
522  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
523  | | |                 None
524  | | |             } else {
527  | | |             }
528  | | |         }
528  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /       int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |       "[0x12]", "[0x12]", "", "" }
     | |__________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:570:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
570  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
574  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
575  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
576  | | |                 None
577  | | |             } else {
580  | | |             }
581  | | |         }
581  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /       int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |       "[0x12]", "[0x12]", "", "" }
     | |__________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:517:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
517  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
521  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
522  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
523  | | |                 None
524  | | |             } else {
527  | | |             }
528  | | |         }
528  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /       int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |       "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:570:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
570  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
574  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
575  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
576  | | |                 None
577  | | |             } else {
580  | | |             }
581  | | |         }
581  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /       int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |       "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:517:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
517  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
521  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
522  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
523  | | |                 None
524  | | |             } else {
527  | | |             }
528  | | |         }
528  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /       int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |       "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |       "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |__________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:570:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
570  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
574  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
575  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
576  | | |                 None
577  | | |             } else {
580  | | |             }
581  | | |         }
581  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /       int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |       "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |       "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |__________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:517:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
517  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
521  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
522  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
523  | | |                 None
524  | | |             } else {
527  | | |             }
528  | | |         }
528  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /       int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |       "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |       "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |__________________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:570:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
570  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
574  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
575  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
576  | | |                 None
577  | | |             } else {
580  | | |             }
581  | | |         }
581  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /       int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |       "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |       "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |__________________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:517:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
517  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
521  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
522  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
523  | | |                 None
524  | | |             } else {
527  | | |             }
528  | | |         }
528  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:118:5
     |
     |
118  | /       int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
119  | |       170141183460469231731687303715884105727, 16,
120  | |       "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
121  | |       "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
...    |
124  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
125  | |         0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
     | |__________________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:570:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
570  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
574  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
575  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
576  | | |                 None
577  | | |             } else {
580  | | |             }
581  | | |         }
581  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:118:5
     |
     |
118  | /       int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
119  | |       170141183460469231731687303715884105727, 16,
120  | |       "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
121  | |       "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
...    |
124  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
125  | |         0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
     | |__________________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:517:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
517  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
521  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
522  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
523  | | |                 None
524  | | |             } else {
527  | | |             }
528  | | |         }
528  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:148:5
     |
     |
148  | /       int_impl! { isize, i64, usize, 64, -9223372036854775808, 9223372036854775807,
149  | |       12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
150  | |        "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
151  | |        "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
152  | |        usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
     | |_________________________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/int_macros.rs:570:9
     |
     |
1    |   / macro_rules! int_impl {
2    |   |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |   |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
570  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
574  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
575  | | |             if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
576  | | |                 None
577  | | |             } else {
580  | | |             }
581  | | |         }
581  | | |         }
     | |_|_________- not a macro
2009 |   |     }
2010 |   | }
2010 |   | }
     |   |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:148:5
     |
     |
148  | /       int_impl! { isize, i64, usize, 64, -9223372036854775808, 9223372036854775807,
149  | |       12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
150  | |        "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
151  | |        "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
152  | |        usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
     | |_________________________________________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/uint_macros.rs:526:9
     |
     |
1    |   / macro_rules! uint_impl {
2    |   |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |   |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
526  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
530  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
531  | | |             if unlikely!(rhs == 0) {
532  | | |                 None
533  | | |             } else {
537  | | |             }
538  | | |         }
538  | | |         }
     | |_|_________- not a macro
1835 |   |     }
1836 |   | }
1836 |   | }
     |   |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:157:5
     |
     |
157  | /       uint_impl! { u8, u8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
158  | |       "[0x12]", "", "" }
     | |________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/uint_macros.rs:578:9
     |
     |
1    |   / macro_rules! uint_impl {
2    |   |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |   |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
578  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
582  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
583  | | |             if unlikely!(rhs == 0) {
584  | | |                 None
585  | | |             } else {
589  | | |             }
590  | | |         }
590  | | |         }
     | |_|_________- not a macro
1835 |   |     }
1836 |   | }
1836 |   | }
     |   |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:157:5
     |
     |
157  | /       uint_impl! { u8, u8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
158  | |       "[0x12]", "", "" }
     | |________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/uint_macros.rs:526:9
     |
     |
1    |   / macro_rules! uint_impl {
2    |   |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |   |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
526  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
530  | / |         pub const fn checked_div(self, rhs: Self) -> Option<Self> {
531  | | |             if unlikely!(rhs == 0) {
532  | | |                 None
533  | | |             } else {
537  | | |             }
538  | | |         }
538  | | |         }
     | |_|_________- not a macro
1835 |   |     }
1836 |   | }
1836 |   | }
     |   |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:656:5
     |
     |
656  | /       uint_impl! { u16, u16, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
657  | |       "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |______________________________________________- in this macro invocation
error: attribute should be applied to a macro
    --> library/core/src/num/uint_macros.rs:578:9
     |
     |
1    |   / macro_rules! uint_impl {
2    |   |     ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
3    |   |         $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |   |         $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...      |
578  |   |         #[allow_internal_unstable(const_int_unchecked_arith)]
     |   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...      |
582  | / |         pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
583  | | |             if unlikely!(rhs == 0) {
584  | | |                 None
585  | | |             } else {
589  | | |             }
590  | | |         }
590  | | |         }
     | |_|_________- not a macro
1835 |   |     }
1836 |   | }
1836 |   | }
     |   |_- in this expansion of `uint_impl!`
    ::: library/core/src/num/mod.rs:656:5
     |
     |
656  | /       uint_impl! { u16, u16, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",

[jhpratt]

If anyone can let me know what I need to do to avoid errors, that would be great! I see that the #[allow_internal_unstable] isn't allowed on non-macros, but without it, I get an error.

[oli-obk]

The attribute you are looking for is rustc_allow_const_fn_unstable, not allow_internal_unstable. We used to use allow_internal_unstable for this, but have moved to a custom attribute.

[jhpratt]

Thanks @oli-obk; I'll give that a shot.

Going to hopefully include some more integer methods as well, as it doesn't look like the list on that issue was exhaustive. Just on the off chance someone wants to review this before it's completed.

[oli-obk]

cc @rust-lang/wg-const-eval stabilization of lots of inherent methods on integers

[rust-log-analyzer]

The job x86_64-gnu-llvm-9 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   Compiling libc v0.2.79
   Compiling std v0.0.0 (/checkout/library/std)
   Compiling compiler_builtins v0.1.39
   Compiling unwind v0.0.0 (/checkout/library/unwind)
error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
517  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /      int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |      "[0x12]", "[0x12]", "", "" }
     | |_________________________________- in this macro invocation

error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
526  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /      int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |      "[0x12]", "[0x12]", "", "" }
     | |_________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
517  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /      int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |      "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_______________________________________________________- in this macro invocation

error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
526  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /      int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |      "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_______________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
517  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /      int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |      "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |      "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |_________________________________________- in this macro invocation

error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
526  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /      int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |      "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |      "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |_________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
517  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /      int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |      "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |      "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |_________________________________________________________________- in this macro invocation

error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
526  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /      int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |      "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |      "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |_________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
517  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:118:5
     |
     |
118  | /      int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
119  | |      170141183460469231731687303715884105727, 16,
120  | |      "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
121  | |      "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
...    |
124  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
125  | |        0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
     | |_________________________________________________________________- in this macro invocation

error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
526  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:118:5
     |
     |
118  | /      int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
119  | |      170141183460469231731687303715884105727, 16,
120  | |      "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
121  | |      "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
...    |
124  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
125  | |        0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
     | |_________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
517  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:148:5
     |
     |
148  | /      int_impl! { isize, i64, usize, 64, -9223372036854775808, 9223372036854775807,
149  | |      12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
150  | |       "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
151  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
152  | |       usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
     | |________________________________________________________________________- in this macro invocation

error: `intrinsics::unchecked_div` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
526  |  |                 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:148:5
     |
     |
148  | /      int_impl! { isize, i64, usize, 64, -9223372036854775808, 9223372036854775807,
149  | |      12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
150  | |       "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
151  | |       "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
152  | |       usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
     | |________________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
570  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /      int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |      "[0x12]", "[0x12]", "", "" }
     | |_________________________________- in this macro invocation

error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
579  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:91:5
     |
     |
91   | /      int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
92   | |      "[0x12]", "[0x12]", "", "" }
     | |_________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
570  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /      int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |      "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_______________________________________________________- in this macro invocation

error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
579  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:97:5
     |
     |
97   | /      int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
98   | |      "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
     | |_______________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
570  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /      int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |      "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |      "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |_________________________________________- in this macro invocation

error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
579  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:103:5
     |
     |
103  | /      int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
104  | |      "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
105  | |      "[0x12, 0x34, 0x56, 0x78]", "", "" }
     | |_________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
570  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /      int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |      "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |      "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |_________________________________________________________________- in this macro invocation

error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
579  |  |                 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
     |  |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:110:5
     |
     |
110  | /      int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
111  | |      "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
112  | |      "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
113  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
     | |_________________________________________________________________- in this macro invocation
     = help: Const-stable functions can only call other const-stable functions


error: `rustc_allow_const_fn_unstable` expects a list of feature names
     |
     |
1    |  / macro_rules! int_impl {
2    |  |     ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
3    |  |      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4    |  |      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
...     |
570  |  |         #[rustc_allow_const_fn_unstable]
     |  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2009 |  |     }
2010 |  | }
2010 |  | }
     |  |_- in this expansion of `int_impl!`
    ::: library/core/src/num/mod.rs:118:5
     |
     |
118  | /      int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
119  | |      170141183460469231731687303715884105727, 16,
120  | |      "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
121  | |      "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
...    |
124  | |      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
125  | |        0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "" }
     | |_________________________________________________________________- in this macro invocation

error: `intrinsics::unchecked_rem` is not yet stable as a const fn
     |

[jhpratt]

Ok, just pushed up what represents the stabilization of all unstably-const inherent integer methods as const fn. The list at the top of this PR is correct.

Let me know what needs to be changed, if anything! I'd absolutely love to see these methods stabilized as const; it would reduce the amount of code written and increase clarity to anyone reading.

[RalfJung]

I assume those all have pretty trivial code, so -- no objections from my side (but this is not a review, I hope someone goes through all of these individually and makes sure they are truly trivially CTFE-safe ;).

What seems fishy though is the use of rustc_allow_const_fn_unstable. Haven't we usually avoided this by marking the intrinsic as const-stable?

[jhpratt]

Yeah, they're all quite trivial to implement, so I suspect they won't change in the slightest in the future.

I can stabilize the intrinsics as const if desired; I've no idea what is typically done.

[CDirkx]

I've looked into stabilizing these methods before, the rustc_allow_const_fn_unstable is indeed not necessary when the intrinsics unchecked_div and unchecked_rem are stabilized. At the time I believed stabilization of these intrinsics was blocked on const_err, but now looking at it I don't think so?

NonZero*::leading_zeros and trailing_zeros are the only remaining const-unstable methods of the non-zero integers, I think they could also be included in this PR.

[jhpratt]

@CDirkx The NonZero* methods are unstable, though, whereas all methods so far mentioned are already stable (just not const).

[RalfJung]

At the time I believed stabilization of these intrinsics was blocked on const_err, but now looking at it I don't think so?

Well, the intrinsics can cause UB. But even if the intrinsics are const-stable, they are still not stable, so they cannot be directly called from stable code -- and the wrappers being stabilized in this PR are all safe.

[jhpratt]

Now that you mention that...I recall there being an issue somewhat recently where someone wanted to block something being const stable if it wasn't stable in general. Would the stabilization of these intrinsics as const fall under that? Or is that someone else's problem (in all seriousness)?

[RalfJung]

Intrinsics are special, almost all of them are unstable and only exposed through other, stable functions.

[jhpratt]

I'm aware. Just wasn't sure if declaring an intrinsic const-stable might have unintended side effects down the road (internally).

[RalfJung]

Well, it's hard to anticipate unanticipated side-effects. ;) It shouldn't have any... right, @oli-obk ?

[oli-obk]

Yea the unchecked_div intrinsic can be made const-stable, we already support the equivalent MIR operation and we may want to lower the intrinsic to that primitive operation at some point.

[jhpratt]

Went ahead and stabilized the two intrinsics as const.

I can't ping teams as I'm not a member of the rust-lang GitHub org, but this needs lang team approval per comments in the code.

@rustbot modify labels to +T-lang

[RalfJung]

These newly-stabilized intrinsics are unsafe, and their UB detection during CTFE is reasonably well-tested in src/test/ui/consts/const-int-unchecked.rs. Anyway that is not even being exposed by this PR, only safe wrappers are.

I think this is ready for FCP by the relevant teams (libs, lang).

[rfcbot]

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

The RFC will be merged soon.

[dtolnay]

@bors r+

[bors]

📌 Commit f55029a has been approved by dtolnay

[bors]

⌛ Testing commit f55029a with merge 4940dd4...

[bors]

☀️ Test successful - checks-actions
Approved by: dtolnay
Pushing 4940dd4 to master...

[jhpratt]

Just seeing the milestone was set to 1.52. Did this miss the cutoff for beta (set to be released this coming Thursday)? If so, the attributes need to be updated in the code.

[RalfJung]

Beta cutoff happens today (always on the Monday before the release, see here). So... this was a race condition.^^

But looking at the beta branch, I think the cutoff did not happen yet, so the Milestone set by the bot is likely wrong. Not sure though. Cc @pietroalbini @Mark-Simulacrum

[jhpratt]

Wouldn't this fall under "promote master to beta", which happens on Tuesday? Unless that document is wrong for whatever reason.

[tspiteri]

It appears to me the critical moment is the merging of the version bump PR which was opened on Friday (T-6) and merged on Saturday, so that this PR did miss 1.51. :(

Locally, run export BRANCH_POINT=git rev-parse $SHA^ in the rust-lang/rust checkout. This should be bors-authored merge into master of the PR before the version bump merged.

[pietroalbini]

We changed the release process a couple releases ago, now the cutoff happens on the Friday PR.

[jhpratt]

Probably worth updating the process document to avoid confusion.

Should I submit a PR to change these few lines or does someone else want to do it? I don't really care either way; it's obviously a trivial change.

Also cc @dtolnay so you don't approve anything else like this 🙂

[m-ou-se]

Should I submit a PR to change these few lines

@jhpratt If you want to do that, that'd be useful. Thanks :)

[pthariensflame]

relnotes needed, I think.