Auto merge of #114065 - lukas-code:u16_from_char, r=dtolnay · rust-lang/rust@361f8ba (original) (raw)
`@@ -87,20 +87,54 @@ impl From for u128 {
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/// Map char with code point in U+0000..=U+00FF to byte in 0x00..=0xFF with same value, failing
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/// if the code point is greater than U+00FF.
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/// Maps a char with code point in U+0000..=U+00FF to a byte in 0x00..=0xFF with same value,
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/// failing if the code point is greater than U+00FF.
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`///
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`` /// See impl From<u8> for char for details on the encoding.
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`#[stable(feature = "u8_from_char", since = "1.59.0")]
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`impl TryFrom for u8 {
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`type Error = TryFromCharError;
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/// Tries to convert a [char] into a [u8].
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///
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/// # Examples
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///
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/// ```
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/// let a = 'ÿ'; // U+00FF
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/// let b = 'Ā'; // U+0100
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/// assert_eq!(u8::try_from(a), Ok(0xFF_u8));
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/// assert!(u8::try_from(b).is_err());
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/// ```
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`#[inline]
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`fn try_from(c: char) -> Result<u8, Self::Error> {
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` u8::try_from(u32::from(c)).map_err(|_| TryFromCharError(()))
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`}
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`}
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/// Maps a char with code point in U+0000..=U+FFFF to a u16 in 0x0000..=0xFFFF with same value,
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/// failing if the code point is greater than U+FFFF.
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///
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/// This corresponds to the UCS-2 encoding, as specified in ISO/IEC 10646:2003.
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#[stable(feature = "u16_from_char", since = "CURRENT_RUSTC_VERSION")]
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impl TryFrom for u16 {
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type Error = TryFromCharError;
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/// Tries to convert a [char] into a [u16].
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///
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/// # Examples
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///
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/// ```
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/// let trans_rights = '⚧'; // U+26A7
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/// let ninjas = '🥷'; // U+1F977
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/// assert_eq!(u16::try_from(trans_rights), Ok(0x26A7_u16));
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/// assert!(u16::try_from(ninjas).is_err());
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/// ```
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#[inline]
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fn try_from(c: char) -> Result<u16, Self::Error> {
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u16::try_from(u32::from(c)).map_err(|_| TryFromCharError(()))
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}
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}
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`` /// Maps a byte in 0x00..=0xFF to a char whose code point has the same value, in U+0000..=U+00FF.
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`///
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`/// Unicode is designed such that this effectively decodes bytes
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