Auto merge of #68505 - skinny121:canonicalize-const-eval-inputs, r=nikomatsakis

[rust.git] / src / libcore / num / mod.rs

diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index 471ab966622495ca55e395999330e813f7aa38f8..43c5f7cf6b939c4a418400c464f5292425ffdf8d 100644 (file)
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -8,9 +8,18 @@
 use crate::fmt;
 use crate::intrinsics;
 use crate::mem;
-use crate::ops;
 use crate::str::FromStr;
 
+// Used because the `?` operator is not allowed in a const context.
+macro_rules! try_opt {
+    ($e:expr) => {
+        match $e {
+            Some(x) => x,
+            None => return None,
+        }
+    };
+}
+
 macro_rules! impl_nonzero_fmt {
     ( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
         $(
@@ -993,26 +1002,27 @@ pub const fn checked_abs(self) -> Option<Self> {
 ```"),
 
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn checked_pow(self, mut exp: u32) -> Option<Self> {
+            pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
                 let mut base = self;
                 let mut acc: Self = 1;
 
                 while exp > 1 {
                     if (exp & 1) == 1 {
-                        acc = acc.checked_mul(base)?;
+                        acc = try_opt!(acc.checked_mul(base));
                     }
                     exp /= 2;
-                    base = base.checked_mul(base)?;
+                    base = try_opt!(base.checked_mul(base));
                 }
 
                 // Deal with the final bit of the exponent separately, since
                 // squaring the base afterwards is not necessary and may cause a
                 // needless overflow.
                 if exp == 1 {
-                    acc = acc.checked_mul(base)?;
+                    acc = try_opt!(acc.checked_mul(base));
                 }
 
                 Some(acc)
@@ -1180,10 +1190,11 @@ pub const fn saturating_mul(self, rhs: Self) -> Self {
 $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn saturating_pow(self, exp: u32) -> Self {
+            pub const fn saturating_pow(self, exp: u32) -> Self {
                 match self.checked_pow(exp) {
                     Some(x) => x,
                     None if self < 0 && exp % 2 == 1 => Self::min_value(),
@@ -1523,10 +1534,11 @@ pub const fn wrapping_abs(self) -> Self {
 $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn wrapping_pow(self, mut exp: u32) -> Self {
+            pub const fn wrapping_pow(self, mut exp: u32) -> Self {
                 let mut base = self;
                 let mut acc: Self = 1;
 
@@ -1900,10 +1912,11 @@ pub const fn overflowing_abs(self) -> (Self, bool) {
 $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
+            pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
                 let mut base = self;
                 let mut acc: Self = 1;
                 let mut overflown = false;
@@ -1949,11 +1962,12 @@ pub fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
             #[rustc_inherit_overflow_checks]
-            pub fn pow(self, mut exp: u32) -> Self {
+            pub const fn pow(self, mut exp: u32) -> Self {
                 let mut base = self;
                 let mut acc = 1;
 
@@ -3119,26 +3133,27 @@ pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
 assert_eq!(", stringify!($SelfT), "::max_value().checked_pow(2), None);", $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn checked_pow(self, mut exp: u32) -> Option<Self> {
+            pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
                 let mut base = self;
                 let mut acc: Self = 1;
 
                 while exp > 1 {
                     if (exp & 1) == 1 {
-                        acc = acc.checked_mul(base)?;
+                        acc = try_opt!(acc.checked_mul(base));
                     }
                     exp /= 2;
-                    base = base.checked_mul(base)?;
+                    base = try_opt!(base.checked_mul(base));
                 }
 
                 // Deal with the final bit of the exponent separately, since
                 // squaring the base afterwards is not necessary and may cause a
                 // needless overflow.
                 if exp == 1 {
-                    acc = acc.checked_mul(base)?;
+                    acc = try_opt!(acc.checked_mul(base));
                 }
 
                 Some(acc)
@@ -3234,10 +3249,11 @@ pub const fn saturating_mul(self, rhs: Self) -> Self {
 $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn saturating_pow(self, exp: u32) -> Self {
+            pub const fn saturating_pow(self, exp: u32) -> Self {
                 match self.checked_pow(exp) {
                     Some(x) => x,
                     None => Self::max_value(),
@@ -3527,10 +3543,11 @@ pub const fn wrapping_shr(self, rhs: u32) -> Self {
 assert_eq!(3u8.wrapping_pow(6), 217);", $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn wrapping_pow(self, mut exp: u32) -> Self {
+            pub const fn wrapping_pow(self, mut exp: u32) -> Self {
                 let mut base = self;
                 let mut acc: Self = 1;
 
@@ -3853,10 +3870,11 @@ pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
 assert_eq!(3u8.overflowing_pow(6), (217, true));", $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_pow", since = "1.34.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
-            pub fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
+            pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
                 let mut base = self;
                 let mut acc: Self = 1;
                 let mut overflown = false;
@@ -3899,11 +3917,12 @@ pub fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
 ", $Feature, "assert_eq!(2", stringify!($SelfT), ".pow(5), 32);", $EndFeature, "
 ```"),
         #[stable(feature = "rust1", since = "1.0.0")]
+        #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
         #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
         #[inline]
         #[rustc_inherit_overflow_checks]
-        pub fn pow(self, mut exp: u32) -> Self {
+        pub const fn pow(self, mut exp: u32) -> Self {
             let mut base = self;
             let mut acc = 1;
 
@@ -4014,7 +4033,8 @@ pub const fn is_power_of_two(self) -> bool {
         // overflow cases it instead ends up returning the maximum value
         // of the type, and can return 0 for 0.
         #[inline]
-        fn one_less_than_next_power_of_two(self) -> Self {
+        #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
+        const fn one_less_than_next_power_of_two(self) -> Self {
             if self <= 1 { return 0; }
 
             let p = self - 1;
@@ -4042,10 +4062,11 @@ fn one_less_than_next_power_of_two(self) -> Self {
 assert_eq!(3", stringify!($SelfT), ".next_power_of_two(), 4);", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
             #[inline]
-            pub fn next_power_of_two(self) -> Self {
-                // Call the trait to get overflow checks
-                ops::Add::add(self.one_less_than_next_power_of_two(), 1)
+            #[rustc_inherit_overflow_checks]
+            pub const fn next_power_of_two(self) -> Self {
+                self.one_less_than_next_power_of_two() + 1
             }
         }
 
@@ -4067,7 +4088,8 @@ pub fn next_power_of_two(self) -> Self {
 ```"),
             #[inline]
             #[stable(feature = "rust1", since = "1.0.0")]
-            pub fn checked_next_power_of_two(self) -> Option<Self> {
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
+            pub const fn checked_next_power_of_two(self) -> Option<Self> {
                 self.one_less_than_next_power_of_two().checked_add(1)
             }
         }
@@ -4091,7 +4113,8 @@ pub fn checked_next_power_of_two(self) -> Option<Self> {
 ```"),
             #[unstable(feature = "wrapping_next_power_of_two", issue = "32463",
                        reason = "needs decision on wrapping behaviour")]
-            pub fn wrapping_next_power_of_two(self) -> Self {
+            #[rustc_const_unstable(feature = "const_int_pow", issue = "53718")]
+            pub const fn wrapping_next_power_of_two(self) -> Self {
                 self.one_less_than_next_power_of_two().wrapping_add(1)
             }
         }
@@ -4301,8 +4324,9 @@ impl u8 {
     /// assert!(!non_ascii.is_ascii());
     /// ```
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[rustc_const_stable(feature = "const_ascii_methods_on_intrinsics", since = "1.43.0")]
     #[inline]
-    pub fn is_ascii(&self) -> bool {
+    pub const fn is_ascii(&self) -> bool {
         *self & 128 == 0
     }