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2020-07-27mv std libs to library/mark-5359/+0
2020-07-27Rollup merge of #73858 - tspiteri:const-methods, r=oli-obkManish Goregaokar-33/+33
Make more primitive integer methods const Now that #72437 has been merged and `const_if_match` is stable, these methods can be stabilized const. The methods are grouped in commits according to feature names: * `const_nonzero_int_methods` - `NonZero*::new` * some `const_checked_int_methods` - `{i*,u*}::checked_add` - `{i*,u*}::checked_sub` - `{i*,u*}::checked_mul` - `{i*,u*}::checked_neg` - `{i*,u*}::checked_shl` - `{i*,u*}::checked_shr` - `i*::checked_abs` * `const_saturating_int_methods` - `{i*,u*}::saturating_add` - `{i*,u*}::saturating_sub` - `{i*,u*}::saturating_mul` - `i*::saturating_neg` - `i*::saturating_abs` * `const_int_sign` - `i*::signum` * `const_ascii_ctype_on_intrinsics` - `{char,u8}::is_ascii_alphabetic` - `{char,u8}::is_ascii_uppercase` - `{char,u8}::is_ascii_lowercase` - `{char,u8}::is_ascii_alphanumeric` - `{char,u8}::is_ascii_digit` - `{char,u8}::is_ascii_hexdigit` - `{char,u8}::is_ascii_punctuation` - `{char,u8}::is_ascii_graphic` - `{char,u8}::is_ascii_whitespace` - `{char,u8}::is_ascii_control`
2020-07-24Rollup merge of #74367 - Neutron3529:patch-1, r=nagisaManish Goregaokar-43/+44
Rearrange the pipeline of `pow` to gain efficiency The check of the `exp` parameter seems useless if we execute the while-loop more than once. The original implementation of `pow` function using one more comparison if the `exp==0` and may break the pipeline of the cpu, which may generate a slower code. The performance gap between the old and the new implementation may be small, but IMO, at least the newer one looks more beautiful. --- bench prog: ``` #![feature(test)] extern crate test; #[macro_export]macro_rules! timing{ ($a:expr)=>{let time=std::time::Instant::now();{$a;}print!("{:?} ",time.elapsed())}; ($a:expr,$b:literal)=>{let time=std::time::Instant::now();let mut a=0;for _ in 0..$b{a^=$a;}print!("{:?} {} ",time.elapsed(),a)} } #[inline] pub fn pow_rust(x:i64, mut exp: u32) -> i64 { let mut base = x; let mut acc = 1; while exp > 1 { if (exp & 1) == 1 { acc = acc * base; } exp /= 2; base = base * base; } if exp == 1 { acc = acc * base; } acc } #[inline] pub fn pow_new(x:i64, mut exp: u32) -> i64 { if exp==0{ 1 }else{ let mut base = x; let mut acc = 1; while exp > 1 { if (exp & 1) == 1 { acc = acc * base; } exp >>= 1; base = base * base; } acc * base } } fn main(){ let a=2i64; let b=1_u32; println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); } ``` bench in my laptop: ``` neutron@Neutron:/me/rust$ rc commit.rs rustc commit.rs && ./commit 3.978419716s 0 4.079765171s 0 3.964630622s 0 3.997127013s 0 4.260304804s 0 3.997638211s 0 3.963195544s 0 4.11657718s 0 4.176054164s 0 3.830128579s 0 3.980396122s 0 3.937258567s 0 3.986055948s 0 4.127804162s 0 4.018943411s 0 4.185568857s 0 4.217512517s 0 3.98313603s 0 3.863018225s 0 4.030447988s 0 3.694878237s 0 4.206987927s 0 4.137608047s 0 4.115564664s 0 neutron@Neutron:/me/rust$ rc commit.rs -O rustc commit.rs -O && ./commit 162.111993ms 0 165.107125ms 0 166.26924ms 0 175.20479ms 0 205.062565ms 0 176.278791ms 0 174.408975ms 0 166.526899ms 0 201.857604ms 0 146.190062ms 0 168.592821ms 0 154.61411ms 0 199.678912ms 0 168.411598ms 0 162.129996ms 0 147.420765ms 0 209.759326ms 0 154.807907ms 0 165.507134ms 0 188.476239ms 0 157.351524ms 0 121.320123ms 0 126.401229ms 0 114.86428ms 0 ```
2020-07-23Rearrange the pipeline of `pow` to gain efficiencyNeutron3529-43/+44
The check of the `exp` parameter seems useless if we execute the while-loop more than once. The original implementation of `pow` function using one more comparison if the `exp==0` and may break the pipeline of the cpu, which may generate a slower code. The performance gap between the old and the new implementation may be small, but IMO, at least the newer one looks more beautiful. --- bench prog: ``` extern crate test; ($a:expr)=>{let time=std::time::Instant::now();{$a;}print!("{:?} ",time.elapsed())}; ($a:expr,$b:literal)=>{let time=std::time::Instant::now();let mut a=0;for _ in 0..$b{a^=$a;}print!("{:?} {} ",time.elapsed(),a)} } pub fn pow_rust(x:i64, mut exp: u32) -> i64 { let mut base = x; let mut acc = 1; while exp > 1 { if (exp & 1) == 1 { acc = acc * base; } exp /= 2; base = base * base; } if exp == 1 { acc = acc * base; } acc } pub fn pow_new(x:i64, mut exp: u32) -> i64 { if exp==0{ 1 }else{ let mut base = x; let mut acc = 1; while exp > 1 { if (exp & 1) == 1 { acc = acc * base; } exp >>= 1; base = base * base; } acc * base } } fn main(){ let a=2i64; let b=1_u32; println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); timing!(test::black_box(a).pow(test::black_box(b)),100000000); timing!(pow_new(test::black_box(a),test::black_box(b)),100000000); timing!(pow_rust(test::black_box(a),test::black_box(b)),100000000); println!(); } ``` bench in my laptop: ``` neutron@Neutron:/me/rust$ rc commit.rs rustc commit.rs && ./commit 3.978419716s 0 4.079765171s 0 3.964630622s 0 3.997127013s 0 4.260304804s 0 3.997638211s 0 3.963195544s 0 4.11657718s 0 4.176054164s 0 3.830128579s 0 3.980396122s 0 3.937258567s 0 3.986055948s 0 4.127804162s 0 4.018943411s 0 4.185568857s 0 4.217512517s 0 3.98313603s 0 3.863018225s 0 4.030447988s 0 3.694878237s 0 4.206987927s 0 4.137608047s 0 4.115564664s 0 neutron@Neutron:/me/rust$ rc commit.rs -O rustc commit.rs -O && ./commit 162.111993ms 0 165.107125ms 0 166.26924ms 0 175.20479ms 0 205.062565ms 0 176.278791ms 0 174.408975ms 0 166.526899ms 0 201.857604ms 0 146.190062ms 0 168.592821ms 0 154.61411ms 0 199.678912ms 0 168.411598ms 0 162.129996ms 0 147.420765ms 0 209.759326ms 0 154.807907ms 0 165.507134ms 0 188.476239ms 0 157.351524ms 0 121.320123ms 0 126.401229ms 0 114.86428ms 0 ``` delete an unnecessary semicolon... Sorry for the typo. delete trailing whitespace Sorry, too.. Sorry for the missing... I checked all the implementations, and finally found that there is one function that does not check whether `exp == 0` add extra tests add extra tests. finished adding the extra tests to prevent further typo add pow(2) to negative exp add whitespace. add whitespace add whitespace delete extra line
2020-07-22mark methods as constant since 1.47.0 instead of 1.46.0Trevor Spiteri-61/+33
2020-07-16apply bootstrap cfgsMark Rousskov-11/+0
2020-07-02Rollup merge of #73938 - nbdd0121:checked_opt, r=nagisaManish Goregaokar-27/+43
Optimise fast path of checked_ops with `unlikely` This PR marks paths returning `None` in checked_ops as unlikely to improvde codegen. Fixes #73731
2020-07-01Optimise fast path of checked_ops with `unlikely`Gary Guo-27/+43
2020-06-30Deny unsafe ops in unsafe fns, part 6LeSeulArtichaut-1/+0
And final part!!!
2020-06-30Deny unsafe ops in unsafe fns, part 3LeSeulArtichaut-7/+21
2020-06-29stabilize const_ascii_ctype_on_intrinsicsTrevor Spiteri-10/+20
2020-06-29stabilize const_int_signTrevor Spiteri-1/+2
2020-06-29stabilize const_saturating_int_methodsTrevor Spiteri-8/+11
2020-06-29stabilize some const_checked_int_methodsTrevor Spiteri-13/+26
2020-06-29stabilize const_nonzero_int_methodsTrevor Spiteri-1/+2
2020-06-29Auto merge of #73032 - yoshuawuyts:stabilize-leading_trailing_ones, r=Amanieubors-12/+12
stabilize leading_trailing_ones This PR stabilizes the `leading_trailing_ones` feature. It's been available on nightly since the start of the year, and hasn't had any issues since. It seems unlikely we'll want to change this, so following up on @djc's suggestion in https://github.com/rust-lang/rust/issues/57969#issuecomment-638405264 I'd like to put forward this PR to stabilize the feature and make it part of `1.46.0`. Thanks! cc/ @djc @rust-lang/libs
2020-06-28Remove `const_if_match` feature gate from librariesDylan MacKenzie-3/+3
2020-06-12Rollup merge of #72906 - lzutao:migrate-numeric-assoc-consts, r=dtolnayDylan DPC-33/+33
Migrate to numeric associated consts The deprecation PR is #72885 cc #68490 cc rust-lang/rfcs#2700
2020-06-11Update src/libcore/num/mod.rsAmanieu d'Antras-2/+2
Co-authored-by: lzutao <taolzu@gmail.com>
2020-06-10Fix doctest templateMihail Malo-1/+2
`saturating_add` example was not parameterized, but passed because the `u8` would saturate successfully
2020-06-10Migrate to numeric associated constsLzu Tao-33/+33
2020-06-05stabilize leading_trailing_onesYoshua Wuyts-12/+12
2020-05-19Rollup merge of #71886 - t-rapp:tr-saturating-funcs, r=dtolnayDylan DPC-6/+4
Stabilize saturating_abs and saturating_neg Stabilizes the following signed integer functions with saturation mechanics: * saturating_abs() * saturating_neg() Closes #59983
2020-05-16Rollup merge of #72224 - lzutao:links, r=Dylan-DPCDylan DPC-8/+8
doc: add links to rotate_(left|right)
2020-05-15Auto merge of #69659 - CAD97:step-rework-take-3, r=Amanieubors-0/+102
Rework the std::iter::Step trait Previous attempts: #43127 #62886 #68807 Tracking issue: #42168 This PR reworks the `Step` trait to be phrased in terms of the *successor* and *predecessor* operations. With this, `Step` hopefully has a consistent identity that can have a path towards stabilization. The proposed trait: ```rust /// Objects that have a notion of *successor* and *predecessor* operations. /// /// The *successor* operation moves towards values that compare greater. /// The *predecessor* operation moves towards values that compare lesser. /// /// # Safety /// /// This trait is `unsafe` because its implementation must be correct for /// the safety of `unsafe trait TrustedLen` implementations, and the results /// of using this trait can otherwise be trusted by `unsafe` code to be correct /// and fulful the listed obligations. pub unsafe trait Step: Clone + PartialOrd + Sized { /// Returns the number of *successor* steps required to get from `start` to `end`. /// /// Returns `None` if the number of steps would overflow `usize` /// (or is infinite, or if `end` would never be reached). /// /// # Invariants /// /// For any `a`, `b`, and `n`: /// /// * `steps_between(&a, &b) == Some(n)` if and only if `Step::forward(&a, n) == Some(b)` /// * `steps_between(&a, &b) == Some(n)` if and only if `Step::backward(&a, n) == Some(a)` /// * `steps_between(&a, &b) == Some(n)` only if `a <= b` /// * Corollary: `steps_between(&a, &b) == Some(0)` if and only if `a == b` /// * Note that `a <= b` does _not_ imply `steps_between(&a, &b) != None`; /// this is the case wheen it would require more than `usize::MAX` steps to get to `b` /// * `steps_between(&a, &b) == None` if `a > b` fn steps_between(start: &Self, end: &Self) -> Option<usize>; /// Returns the value that would be obtained by taking the *successor* /// of `self` `count` times. /// /// If this would overflow the range of values supported by `Self`, returns `None`. /// /// # Invariants /// /// For any `a`, `n`, and `m`: /// /// * `Step::forward_checked(a, n).and_then(|x| Step::forward_checked(x, m)) == Step::forward_checked(a, m).and_then(|x| Step::forward_checked(x, n))` /// /// For any `a`, `n`, and `m` where `n + m` does not overflow: /// /// * `Step::forward_checked(a, n).and_then(|x| Step::forward_checked(x, m)) == Step::forward_checked(a, n + m)` /// /// For any `a` and `n`: /// /// * `Step::forward_checked(a, n) == (0..n).try_fold(a, |x, _| Step::forward_checked(&x, 1))` /// * Corollary: `Step::forward_checked(&a, 0) == Some(a)` fn forward_checked(start: Self, count: usize) -> Option<Self>; /// Returns the value that would be obtained by taking the *successor* /// of `self` `count` times. /// /// If this would overflow the range of values supported by `Self`, /// this function is allowed to panic, wrap, or saturate. /// The suggested behavior is to panic when debug assertions are enabled, /// and to wrap or saturate otherwise. /// /// Unsafe code should not rely on the correctness of behavior after overflow. /// /// # Invariants /// /// For any `a`, `n`, and `m`, where no overflow occurs: /// /// * `Step::forward(Step::forward(a, n), m) == Step::forward(a, n + m)` /// /// For any `a` and `n`, where no overflow occurs: /// /// * `Step::forward_checked(a, n) == Some(Step::forward(a, n))` /// * `Step::forward(a, n) == (0..n).fold(a, |x, _| Step::forward(x, 1))` /// * Corollary: `Step::forward(a, 0) == a` /// * `Step::forward(a, n) >= a` /// * `Step::backward(Step::forward(a, n), n) == a` fn forward(start: Self, count: usize) -> Self { Step::forward_checked(start, count).expect("overflow in `Step::forward`") } /// Returns the value that would be obtained by taking the *successor* /// of `self` `count` times. /// /// # Safety /// /// It is undefined behavior for this operation to overflow the /// range of values supported by `Self`. If you cannot guarantee that this /// will not overflow, use `forward` or `forward_checked` instead. /// /// # Invariants /// /// For any `a`: /// /// * if there exists `b` such that `b > a`, it is safe to call `Step::forward_unchecked(a, 1)` /// * if there exists `b`, `n` such that `steps_between(&a, &b) == Some(n)`, /// it is safe to call `Step::forward_unchecked(a, m)` for any `m <= n`. /// /// For any `a` and `n`, where no overflow occurs: /// /// * `Step::forward_unchecked(a, n)` is equivalent to `Step::forward(a, n)` #[unstable(feature = "unchecked_math", reason = "niche optimization path", issue = "none")] unsafe fn forward_unchecked(start: Self, count: usize) -> Self { Step::forward(start, count) } /// Returns the value that would be obtained by taking the *successor* /// of `self` `count` times. /// /// If this would overflow the range of values supported by `Self`, returns `None`. /// /// # Invariants /// /// For any `a`, `n`, and `m`: /// /// * `Step::backward_checked(a, n).and_then(|x| Step::backward_checked(x, m)) == n.checked_add(m).and_then(|x| Step::backward_checked(a, x))` /// * `Step::backward_checked(a, n).and_then(|x| Step::backward_checked(x, m)) == try { Step::backward_checked(a, n.checked_add(m)?) }` /// /// For any `a` and `n`: /// /// * `Step::backward_checked(a, n) == (0..n).try_fold(a, |x, _| Step::backward_checked(&x, 1))` /// * Corollary: `Step::backward_checked(&a, 0) == Some(a)` fn backward_checked(start: Self, count: usize) -> Option<Self>; /// Returns the value that would be obtained by taking the *predecessor* /// of `self` `count` times. /// /// If this would overflow the range of values supported by `Self`, /// this function is allowed to panic, wrap, or saturate. /// The suggested behavior is to panic when debug assertions are enabled, /// and to wrap or saturate otherwise. /// /// Unsafe code should not rely on the correctness of behavior after overflow. /// /// # Invariants /// /// For any `a`, `n`, and `m`, where no overflow occurs: /// /// * `Step::backward(Step::backward(a, n), m) == Step::backward(a, n + m)` /// /// For any `a` and `n`, where no overflow occurs: /// /// * `Step::backward_checked(a, n) == Some(Step::backward(a, n))` /// * `Step::backward(a, n) == (0..n).fold(a, |x, _| Step::backward(x, 1))` /// * Corollary: `Step::backward(a, 0) == a` /// * `Step::backward(a, n) <= a` /// * `Step::forward(Step::backward(a, n), n) == a` fn backward(start: Self, count: usize) -> Self { Step::backward_checked(start, count).expect("overflow in `Step::backward`") } /// Returns the value that would be obtained by taking the *predecessor* /// of `self` `count` times. /// /// # Safety /// /// It is undefined behavior for this operation to overflow the /// range of values supported by `Self`. If you cannot guarantee that this /// will not overflow, use `backward` or `backward_checked` instead. /// /// # Invariants /// /// For any `a`: /// /// * if there exists `b` such that `b < a`, it is safe to call `Step::backward_unchecked(a, 1)` /// * if there exists `b`, `n` such that `steps_between(&b, &a) == Some(n)`, /// it is safe to call `Step::backward_unchecked(a, m)` for any `m <= n`. /// /// For any `a` and `n`, where no overflow occurs: /// /// * `Step::backward_unchecked(a, n)` is equivalent to `Step::backward(a, n)` #[unstable(feature = "unchecked_math", reason = "niche optimization path", issue = "none")] unsafe fn backward_unchecked(start: Self, count: usize) -> Self { Step::backward(start, count) } } ``` Note that all of these are associated functions and not callable via method syntax; the calling syntax is always `Step::forward(start, n)`. This version of the trait additionally changes the stepping functions to talk their arguments by value. As opposed to previous attempts which provided a "step by one" method directly, this version of the trait only exposes "step by n". There are a few reasons for this: - `Range*`, the primary consumer of `Step`, assumes that the "step by n" operation is cheap. If a single step function is provided, it will be a lot more enticing to implement "step by n" as n repeated calls to "step by one". While this is not strictly incorrect, this behavior would be surprising for anyone used to using `Range<{primitive integer}>`. - With a trivial default impl, this can be easily added backwards-compatibly later. - The debug-wrapping "step by n" needs to exist for `RangeFrom` to be consistent between "step by n" and "step by one" operation. (Note: the behavior is not changed by this PR, but making the behavior consistent is made tenable by this PR.) Three "kinds" of step are provided: `_checked`, which returns an `Option` indicating attempted overflow; (unsuffixed), which provides "safe overflow" behavior (is allowed to panic, wrap, or saturate, depending on what is most convenient for a given type); and `_unchecked`, which is a version which assumes overflow does not happen. Review is appreciated to check that: - The invariants as described on the `Step` functions are enough to specify the "common sense" consistency for successor/predecessor. - Implementation of `Step` functions is correct in the face of overflow and the edges of representable integers. - Added tests of `Step` functions are asserting the correct behavior (and not just the implemented behavior).
2020-05-15doc: add links to rotate_(left|right)Lzu Tao-8/+8
2020-05-04Stabilize saturating_abs and saturating_negTobias Rapp-6/+4
Stabilizes the following signed integer functions with saturation mechanics: * saturating_abs() * saturating_neg() Closes #59983
2020-04-26Fix since attribute for nonzero_bitor impl'sJonas Platte-5/+5
2020-04-25Rollup merge of #69813 - thomcc:nonzero-bitor, r=AmanieuDylan DPC-0/+52
Implement BitOr and BitOrAssign for the NonZero integer types This provides overloaded operators for `NonZero$Int | NonZero$Int`, `NonZero$Int | $Int`, and `$Int | NonZero$Int`. It also provides `BitOrAssign` where `self` is `NonZero$Int`, for symmetry. It's a pretty small conceptual addition, but is good becasue but avoids a case where the operation is obviously sound, but you'd otherwise need unsafe to do it. In crates trying to minimize `unsafe` usage, this is unfortunate and makes working with `NonZero` types often not worth it, even if the operations you're doing are clearly sound. I've marked these as stable as I've been told in the past that trait impls are automatically stable. I'm happy to change it to unstable if this wasn't correct information. I'm not entirely confident what version I should have put down, so I followed https://www.whatrustisit.com. Hopefully it's correct for this. Apologies in advance if this has come up before, but I couldn't find it.
2020-04-08Add inherent impls for unchecked math intrinsicsCAD97-0/+102
2020-04-03Make documentation examples use new integer assoc constsLinus Färnstrand-1/+1
2020-04-02Fix typo in u8::to_ascii_uppercase and u8::to_ascii_lowercasePocakking-2/+2
fith => fifth
2020-03-13update stable-since version for const_int_conversionTrevor Spiteri-12/+12
2020-03-11Rollup merge of #69373 - tspiteri:const_int_conversion, r=oli-obkMazdak Farrokhzad-16/+48
Stabilize const for integer {to,from}_{be,le,ne}_bytes methods All of these functions can be implemented simply and naturally as const functions, e.g. `u32::from_le_bytes` can be implemented as ```rust (bytes[0] as u32) | (bytes[1] as u32) << 8 | (bytes[2] as u32) << 16 | (bytes[3] as u32) << 24 ``` So stabilizing the constness will not expose that internally they are implemented using transmute which is not const in stable.
2020-03-07Implement BitOr and BitOrAssign for the NonZero integer typesThom Chiovoloni-0/+52
2020-03-04Auto merge of #68952 - faern:stabilize-assoc-int-consts, r=dtolnaybors-135/+129
Stabilize assoc_int_consts associated int/float constants The next step in RFC https://github.com/rust-lang/rfcs/pull/2700 (tracking issue #68490). Stabilizing the associated constants that were added in #68325. * Stabilize all constants under the `assoc_int_consts` feature flag. * Update documentation on old constants to say they are soft-deprecated and the new ones should be preferred. * Update documentation examples to use new constants. * Remove `uint_macro` and use `int_macro` for all integer types since the macros were identical anyway. r? @LukasKalbertodt
2020-02-26use unions instead of transmute and add const safety commentsTrevor Spiteri-8/+36
2020-02-22Rollup merge of #68984 - ecstatic-morse:const-u8-is-ascii, r=sfacklerDylan DPC-1/+2
Make `u8::is_ascii` a stable `const fn` `char::is_ascii` was already stabilized as `const fn` in #55278, so there is no reason for `u8::is_ascii` to go through an unstable period. cc @rust-lang/libs
2020-02-22Stabilize const for integer {to,from}_{be,le,ne}_bytes methodsTrevor Spiteri-12/+16
All of these functions can be implemented simply and naturally as const functions, e.g. u32::from_le_bytes can be implemented as (bytes[0] as u32) | (bytes[1] as u32) << 8 | (bytes[2] as u32) << 16 | (bytes[3] as u32) << 24 So stabilizing the constness will not expose that internally they are implemented using transmute which is not const in stable.
2020-02-20Rollup merge of #68978 - ecstatic-morse:const-int-pow, r=oli-obkDylan DPC-23/+46
Make integer exponentiation methods unstably const cc #53718 This makes the following inherent methods on integer primitives into unstable `const fn`: - `pow` - `checked_pow` - `wrapping_pow` - `overflowing_pow` - `saturating_pow` - `next_power_of_two` - `checked_next_power_of_two` - `wrapping_next_power_of_two` Only two changes were made to the implementation of these methods. First, I had to switch from the `?` operator, which is not yet implemented in a const context, to a `try_opt` macro. Second, `next_power_of_two` was using `ops::Add::add` (see the first commit) to "get overflow checks", so I switched to `#[rustc_inherit_overflow_checks]`. I'm not quite sure why the attribute wasn't used in the first place.
2020-02-12Replace min/max_value() with MIN/MAX in integer docsLinus Färnstrand-52/+52
2020-02-12Use new preferred consts in int docsLinus Färnstrand-35/+13
2020-02-12Add "soft deprecation" notice to old min/max_value() docsLinus Färnstrand-40/+60
2020-02-12Stabilize assoc_int_constsLinus Färnstrand-8/+4
2020-02-10Rollup merge of #68986 - ecstatic-morse:const-ascii-ctype, r=CentrilDylan DPC-10/+20
Make ASCII ctype functions unstably const Makes the following inherent methods on `u8` and `char` unstable `const fn`: * `is_ascii_alphabetic` * `is_ascii_uppercase` * `is_ascii_lowercase` * `is_ascii_alphanumeric` * `is_ascii_digit` * `is_ascii_hexdigit` * `is_ascii_punctuation` * `is_ascii_graphic` * `is_ascii_whitespace` * `is_ascii_control` cc #68983
2020-02-08Make `u8::is_ascii` a stable `const fn`Dylan MacKenzie-1/+2
`char::is_ascii` is already a stable `const fn`, so there is no reason for `u8::is_ascii` to be unstable.
2020-02-08Make the ASCII ctype inherent methods constDylan MacKenzie-10/+20
2020-02-08Make integer power methods constDylan MacKenzie-14/+28
2020-02-08Use bespoke macro instead of `?` inside const fnsDylan MacKenzie-6/+16
2020-02-08[!] Use `rustc_inherit_overflow_checks` in `next_power_of_two`Dylan MacKenzie-3/+2
I believe the previous code was calling `ops::Add::add` instead of the `+` operator to get this behavior.