Add 'must_use' attribute to 'char::len_utf8' and 'char::len_utf16';

bjoernager · bjoernager · commit e4f89ece58f5 · 2024-09-25T10:42:43.000+02:00
diff --git a/core/src/char/methods.rs b/core/src/char/methods.rs
@@ -606,6 +606,7 @@ impl char {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_char_len_utf", since = "1.52.0")]
     #[inline]
+    #[must_use]
     pub const fn len_utf8(self) -> usize {
         len_utf8(self as u32)
     }
@@ -637,6 +638,7 @@ impl char {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_char_len_utf", since = "1.52.0")]
     #[inline]
+    #[must_use]
     pub const fn len_utf16(self) -> usize {
         len_utf16(self as u32)
     }
@@ -1738,6 +1740,7 @@ impl EscapeDebugExtArgs {
 }
 
 #[inline]
+#[must_use]
 const fn len_utf8(code: u32) -> usize {
     match code {
         ..MAX_ONE_B => 1,
@@ -1748,6 +1751,7 @@ const fn len_utf8(code: u32) -> usize {
 }
 
 #[inline]
+#[must_use]
 const fn len_utf16(code: u32) -> usize {
     if (code & 0xFFFF) == code { 1 } else { 2 }
 }

Original file line number	Diff line number	Diff line change
`@@ -606,6 +606,7 @@ impl char {`
`606`	`606`	`#[stable(feature = "rust1", since = "1.0.0")]`
`607`	`607`	`#[rustc_const_stable(feature = "const_char_len_utf", since = "1.52.0")]`
`608`	`608`	`#[inline]`
	`609`	`+ #[must_use]`
`609`	`610`	`pub const fn len_utf8(self) -> usize {`
`610`	`611`	`len_utf8(self as u32)`
`611`	`612`	`}`
`@@ -637,6 +638,7 @@ impl char {`
`637`	`638`	`#[stable(feature = "rust1", since = "1.0.0")]`
`638`	`639`	`#[rustc_const_stable(feature = "const_char_len_utf", since = "1.52.0")]`
`639`	`640`	`#[inline]`
	`641`	`+ #[must_use]`
`640`	`642`	`pub const fn len_utf16(self) -> usize {`
`641`	`643`	`len_utf16(self as u32)`
`642`	`644`	`}`
`@@ -1738,6 +1740,7 @@ impl EscapeDebugExtArgs {`
`1738`	`1740`	`}`
`1739`	`1741`
`1740`	`1742`	`#[inline]`
	`1743`	`+#[must_use]`
`1741`	`1744`	`const fn len_utf8(code: u32) -> usize {`
`1742`	`1745`	`match code {`
`1743`	`1746`	`..MAX_ONE_B => 1,`
`@@ -1748,6 +1751,7 @@ const fn len_utf8(code: u32) -> usize {`
`1748`	`1751`	`}`
`1749`	`1752`
`1750`	`1753`	`#[inline]`
	`1754`	`+#[must_use]`
`1751`	`1755`	`const fn len_utf16(code: u32) -> usize {`
`1752`	`1756`	`if (code & 0xFFFF) == code { 1 } else { 2 }`
`1753`	`1757`	`}`