diff options
| -rw-r--r-- | library/core/src/fmt/num.rs | 88 |
1 files changed, 48 insertions, 40 deletions
diff --git a/library/core/src/fmt/num.rs b/library/core/src/fmt/num.rs index 7d41ae45093..a52749d4325 100644 --- a/library/core/src/fmt/num.rs +++ b/library/core/src/fmt/num.rs @@ -54,44 +54,31 @@ unsafe trait GenericRadix: Sized { /// Converts an integer to corresponding radix digit. fn digit(x: u8) -> u8; - /// Format an integer using the radix using a formatter. + /// Format an unsigned integer using the radix using a formatter. fn fmt_int<T: DisplayInt>(&self, mut x: T, f: &mut fmt::Formatter<'_>) -> fmt::Result { // The radix can be as low as 2, so we need a buffer of at least 128 // characters for a base 2 number. let zero = T::zero(); - let is_nonnegative = x >= zero; let mut buf = [MaybeUninit::<u8>::uninit(); 128]; let mut offset = buf.len(); let base = T::from_u8(Self::BASE); - if is_nonnegative { - // Accumulate each digit of the number from the least significant - // to the most significant figure. - loop { - let n = x % base; // Get the current place value. - x = x / base; // Deaccumulate the number. - offset -= 1; - buf[offset].write(Self::digit(n.to_u8())); // Store the digit in the buffer. - if x == zero { - // No more digits left to accumulate. - break; - }; - } - } else { - // Do the same as above, but accounting for two's complement. - loop { - let n = zero - (x % base); // Get the current place value. - x = x / base; // Deaccumulate the number. - offset -= 1; - buf[offset].write(Self::digit(n.to_u8())); // Store the digit in the buffer. - if x == zero { - // No more digits left to accumulate. - break; - }; - } + + // Accumulate each digit of the number from the least significant + // to the most significant figure. + loop { + let n = x % base; // Get the current place value. + x = x / base; // Deaccumulate the number. + offset -= 1; + buf[offset].write(Self::digit(n.to_u8())); // Store the digit in the buffer. + if x == zero { + // No more digits left to accumulate. + break; + }; } + // SAFETY: Starting from `offset`, all elements of the slice have been set. - let buf_slice = unsafe { slice_buffer_to_str(&buf, offset) }; - f.pad_integral(is_nonnegative, Self::PREFIX, buf_slice) + let digits = unsafe { slice_buffer_to_str(&buf, offset) }; + f.pad_integral(true, Self::PREFIX, digits) } } @@ -132,11 +119,11 @@ radix! { LowerHex, 16, "0x", x @ 0 ..= 9 => b'0' + x, x @ 10 ..= 15 => b'a' + radix! { UpperHex, 16, "0x", x @ 0 ..= 9 => b'0' + x, x @ 10 ..= 15 => b'A' + (x - 10) } macro_rules! int_base { - (fmt::$Trait:ident for $T:ident as $U:ident -> $Radix:ident) => { + (fmt::$Trait:ident for $T:ident -> $Radix:ident) => { #[stable(feature = "rust1", since = "1.0.0")] impl fmt::$Trait for $T { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - $Radix.fmt_int(*self as $U, f) + $Radix.fmt_int(*self, f) } } }; @@ -144,15 +131,36 @@ macro_rules! int_base { macro_rules! integer { ($Int:ident, $Uint:ident) => { - int_base! { fmt::Binary for $Int as $Uint -> Binary } - int_base! { fmt::Octal for $Int as $Uint -> Octal } - int_base! { fmt::LowerHex for $Int as $Uint -> LowerHex } - int_base! { fmt::UpperHex for $Int as $Uint -> UpperHex } - - int_base! { fmt::Binary for $Uint as $Uint -> Binary } - int_base! { fmt::Octal for $Uint as $Uint -> Octal } - int_base! { fmt::LowerHex for $Uint as $Uint -> LowerHex } - int_base! { fmt::UpperHex for $Uint as $Uint -> UpperHex } + int_base! { fmt::Binary for $Uint -> Binary } + int_base! { fmt::Octal for $Uint -> Octal } + int_base! { fmt::LowerHex for $Uint -> LowerHex } + int_base! { fmt::UpperHex for $Uint -> UpperHex } + + // Format signed integers as unsigned (two’s complement representation). + #[stable(feature = "rust1", since = "1.0.0")] + impl fmt::Binary for $Int { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt::Binary::fmt(&self.cast_unsigned(), f) + } + } + #[stable(feature = "rust1", since = "1.0.0")] + impl fmt::Octal for $Int { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt::Octal::fmt(&self.cast_unsigned(), f) + } + } + #[stable(feature = "rust1", since = "1.0.0")] + impl fmt::LowerHex for $Int { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt::LowerHex::fmt(&self.cast_unsigned(), f) + } + } + #[stable(feature = "rust1", since = "1.0.0")] + impl fmt::UpperHex for $Int { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt::UpperHex::fmt(&self.cast_unsigned(), f) + } + } }; } integer! { isize, usize } |