vim-patch:6fd4f6c: runtime(cpp): Update syntax, cleanup

- Prefer non-capturing groups in patterns - idiomatic.
- Remove changelog entries - there is no maintainer to inform.
- Normalise whitespace use.

closes: vim/vim#21348

https://github.com/vim/vim/commit/6fd4f6cda1602fc0fedcdf4af64f528a3cad9273

Co-authored-by: Doug Kearns <dougkearns@gmail.com>

1 files changed, 44 insertions, 51 deletions

diff --git a/runtime/syntax/cpp.vim b/runtime/syntax/cpp.vim
index 78d3f217ca..03cd8acc29 100644
--- a/runtime/syntax/cpp.vim
+++ b/runtime/syntax/cpp.vim
@@ -1,16 +1,9 @@
 " Vim syntax file
-" Language:	C++
+" Language:		C++
 " Maintainer:		This runtime file is looking for a new maintainer.
-" Previous Maintainer:	vim-jp (https://github.com/vim-jp/vim-cpp)
+" Previous Maintainers:	vim-jp (https://github.com/vim-jp/vim-cpp)
 "			Ken Shan <ccshan@post.harvard.edu>
-" Last Change:	2024 May 04
-"   2024 May 04 by Vim Project fix digit separator in octals and floats
-"   2026 Jan 06 by Vim Project orphaning announcement
-"   2026 Jan 08 by Vim Project highlight capital letter prefixes for numbers
-"   2026 May 29 by Vim Project add C++23 stdfloat types (#16498)
-"   2026 Sep 14 by Vim Project support number suffix uz for C++23 (#21281)
-"   2026 Sep 14 by Vim Project fix number patterns to avoid catastrophic
-"                              backtracking under re=1
+" Last Change:		2026 Sep 16
 
 " quit when a syntax file was already loaded
 if exists("b:current_syntax")
@@ -33,8 +26,8 @@ syn keyword cppType		bool wchar_t
 syn keyword cppExceptions	throw try catch
 syn keyword cppOperator		operator typeid
 syn keyword cppOperator		and bitor or xor compl bitand and_eq or_eq xor_eq not not_eq
-syn match cppCast		"\<\(const\|static\|dynamic\|reinterpret\)_cast\s*<"me=e-1
-syn match cppCast		"\<\(const\|static\|dynamic\|reinterpret\)_cast\s*$"
+syn match cppCast		"\<\%(const\|static\|dynamic\|reinterpret\)_cast\s*<"me=e-1
+syn match cppCast		"\<\%(const\|static\|dynamic\|reinterpret\)_cast\s*$"
 syn keyword cppStorageClass	mutable
 syn keyword cppStructure	class typename template namespace
 syn keyword cppBoolean		true false
@@ -53,31 +46,31 @@ if !exists("cpp_no_cpp11")
   syn keyword cppConstant	ATOMIC_WCHAR_T_LOCK_FREE ATOMIC_SHORT_LOCK_FREE
   syn keyword cppConstant	ATOMIC_INT_LOCK_FREE ATOMIC_LONG_LOCK_FREE
   syn keyword cppConstant	ATOMIC_LLONG_LOCK_FREE ATOMIC_POINTER_LOCK_FREE
-  syn region cppRawString	matchgroup=cppRawStringDelimiter start=+\%(u8\|[uLU]\)\=R"\z([[:alnum:]_{}[\]#<>%:;.?*\+\-/\^&|~!=,"']\{,16}\)(+ end=+)\z1"\(sv\|s\|_[_a-zA-Z][_a-zA-Z0-9]*\)\=+ contains=@Spell
-  syn match cppCast		"\<\(const\|static\|dynamic\)_pointer_cast\s*<"me=e-1
-  syn match cppCast		"\<\(const\|static\|dynamic\)_pointer_cast\s*$"
+  syn region cppRawString	matchgroup=cppRawStringDelimiter start=+\%(u8\|[uLU]\)\=R"\z([[:alnum:]_{}[\]#<>%:;.?*\+\-/\^&|~!=,"']\{,16}\)(+ end=+)\z1"\%(sv\|s\|_[_a-zA-Z][_a-zA-Z0-9]*\)\=+ contains=@Spell
+  syn match cppCast		"\<\%(const\|static\|dynamic\)_pointer_cast\s*<"me=e-1
+  syn match cppCast		"\<\%(const\|static\|dynamic\)_pointer_cast\s*$"
 endif
 
 " C++ 14 extensions
 if !exists("cpp_no_cpp14")
   syn match cppNumbers		display transparent "\<\d\|\.\d" contains=cppNumber,cppFloat
-  syn match cppNumber		display contained "\<0\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppNumber		display contained "\<[1-9]\d*\('\d\+\)*\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppNumber		display contained "\<0\o*\('\o\+\)*\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppNumber		display contained "\<0[Bb][01]\+\('[01]\+\)*\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppNumber		display contained "\<0[Xx]\x\+\('\x\+\)*\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppFloat		display contained "\<\d\+\('\d\+\)*\.\(\d\+\('\d\+\)*\)\=\([Ee][-+]\=\d\+\)\=\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppFloat		display contained "\.\d\+\('\d\+\)*\([Ee][-+]\=\d\+\)\=\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppFloat		display contained "\<\d\+[Ee][-+]\=\d\+\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn region cppString		start=+\(L\|u\|u8\|U\)\="+ skip=+\\\\\|\\"\|\\$+ excludenl end=+"\(sv\|s\|_\i*\)\=+ end='$' contains=cSpecial,cFormat,@Spell
+  syn match cppNumber		display contained "\<0\%([Uu]\=\%([Ll]\|LL\|ll\)\|\%([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<[1-9]\d*\%('\d\+\)*\%([Uu]\=\%([Ll]\|LL\|ll\)\|\%([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<0\o*\%('\o\+\)*\%([Uu]\=\%([Ll]\|LL\|ll\)\|\%([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<0[Bb][01]\+\%('[01]\+\)*\%([Uu]\=\%([Ll]\|LL\|ll\)\|\%([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<0[Xx]\x\+\%('\x\+\)*\%([Uu]\=\%([Ll]\|LL\|ll\)\|\%([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<\d\+\%('\d\+\)*\.\%(\d\+\%('\d\+\)*\)\=\%([Ee][-+]\=\d\+\)\=\%([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\.\d\+\%('\d\+\)*\%([Ee][-+]\=\d\+\)\=\%([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<\d\+[Ee][-+]\=\d\+\%([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn region cppString		start=+\%(L\|u\|u8\|U\)\="+ skip=+\\\\\|\\"\|\\$+ excludenl end=+"\%(sv\|s\|_\i*\)\=+ end='$' contains=cSpecial,cFormat,@Spell
 endif
 
 " C++ 17 extensions
 if !exists("cpp_no_cpp17")
   syn match cppCast		"\<reinterpret_pointer_cast\s*<"me=e-1
   syn match cppCast		"\<reinterpret_pointer_cast\s*$"
-  syn match cppFloat		display contained "\<0[Xx]\(\x\+\('\x\+\)*\)\=\.\x\+\('\x\+\)*[Pp][-+]\=\d\+\('\d\+\)*\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn match cppFloat		display contained "\<0[Xx]\x\+\('\x\+\)*\.\=[Pp][-+]\=\d\+\('\d\+\)*\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<0[Xx]\%(\x\+\%('\x\+\)*\)\=\.\x\+\%('\x\+\)*[Pp][-+]\=\d\+\%('\d\+\)*\%([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<0[Xx]\x\+\%('\x\+\)*\.\=[Pp][-+]\=\d\+\%('\d\+\)*\%([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
 
   " TODO: push this up to c.vim if/when supported in C23
   syn match cppCharacter	"u8'[^\\]'"
@@ -96,11 +89,11 @@ endif
 
 " C++ 20 extensions
 if !exists("cpp_no_cpp20")
-  syn match cppNumber		display contained "\<0\(y\|d\)\>"
-  syn match cppNumber		display contained "\<[1-9]\d*\('\d\+\)*\(y\|d\)\>"
-  syn match cppNumber		display contained "\<0\o\+\(y\|d\)\>"
-  syn match cppNumber		display contained "\<0[Bb][01]\+\('[01]\+\)*\(y\|d\)\>"
-  syn match cppNumber		display contained "\<0[Xx]\x\+\('\x\+\)*\(y\|d\)\>"
+  syn match cppNumber		display contained "\<0\%(y\|d\)\>"
+  syn match cppNumber		display contained "\<[1-9]\d*\%('\d\+\)*\%(y\|d\)\>"
+  syn match cppNumber		display contained "\<0\o\+\%(y\|d\)\>"
+  syn match cppNumber		display contained "\<0[Bb][01]\+\%('[01]\+\)*\%(y\|d\)\>"
+  syn match cppNumber		display contained "\<0[Xx]\x\+\%('\x\+\)*\%(y\|d\)\>"
   syn keyword cppStatement	co_await co_return co_yield requires
   syn keyword cppStorageClass	consteval constinit
   syn keyword cppStructure	concept
@@ -110,11 +103,11 @@ endif
 
 " C++ 23 extensions
 if !exists("cpp_no_cpp23")
-  syn match cppNumber		display contained "\<0\([Zz][Uu]\=\|[Uu][Zz]\)\>"
-  syn match cppNumber		display contained "\<[1-9]\d*\('\d\+\)*\([Zz][Uu]\=\|[Uu][Zz]\)\>"
-  syn match cppNumber		display contained "\<0\o*\('\o\+\)*\([Zz][Uu]\=\|[Uu][Zz]\)\>"
-  syn match cppNumber		display contained "\<0[Bb][01]\+\('[01]\+\)*\([Zz][Uu]\=\|[Uu][Zz]\)\>"
-  syn match cppNumber		display contained "\<0[Xx]\x\+\('\x\+\)*\([Zz][Uu]\=\|[Uu][Zz]\)\>"
+  syn match cppNumber		display contained "\<0\%([Zz][Uu]\=\|[Uu][Zz]\)\>"
+  syn match cppNumber		display contained "\<[1-9]\d*\%('\d\+\)*\%([Zz][Uu]\=\|[Uu][Zz]\)\>"
+  syn match cppNumber		display contained "\<0\o*\%('\o\+\)*\%([Zz][Uu]\=\|[Uu][Zz]\)\>"
+  syn match cppNumber		display contained "\<0[Bb][01]\+\%('[01]\+\)*\%([Zz][Uu]\=\|[Uu][Zz]\)\>"
+  syn match cppNumber		display contained "\<0[Xx]\x\+\%('\x\+\)*\%([Zz][Uu]\=\|[Uu][Zz]\)\>"
   syn match cppFloat		display contained "\<\d\+\%('\d\+\)*\.\%(\d\+\%('\d\+\)*\)\=\%([Ee][-+]\=\d\+\%('\d\+\)*\)\=\%([Ff]\%(16\|32\|64\|128\)\|\%(BF\|bf\)16\)\>"
   syn match cppFloat		display contained "\.\d\+\%('\d\+\)*\%([Ee][-+]\=\d\+\%('\d\+\)*\)\=\%([Ff]\%(16\|32\|64\|128\)\|\%(BF\|bf\)16\)\=\>"
   syn match cppFloat		display contained "\<0[Xx]\%(\x\+\%('\x\+\)*\)\=\.\x\+\%('\x\+\)*[Pp][-+]\=\d\+\%('\d\+\)*\%([Ff]\%(16\|32\|64\|128\)\|\%(BF\|bf\)16\)\=\>"
@@ -135,29 +128,29 @@ endif
 syn match cppMinMax "[<>]?"
 
 " Default highlighting
-hi def link cppAccess		cppStatement
-hi def link cppCast		cppStatement
+hi def link cppAccess			cppStatement
+hi def link cppCast			cppStatement
 hi def link cppExceptions		Exception
-hi def link cppOperator		Operator
+hi def link cppOperator			Operator
 hi def link cppStatement		Statement
-hi def link cppModifier		Type
-hi def link cppType		Type
-hi def link cppStorageClass	StorageClass
+hi def link cppModifier			Type
+hi def link cppType			Type
+hi def link cppStorageClass		StorageClass
 hi def link cppStructure		Structure
-hi def link cppBoolean		Boolean
+hi def link cppBoolean			Boolean
 hi def link cppCharacter		cCharacter
 hi def link cppSpecialCharacter		cSpecialCharacter
 hi def link cppSpecialError		cSpecialError
-hi def link cppConstant		Constant
+hi def link cppConstant			Constant
 hi def link cppRawStringDelimiter	Delimiter
 hi def link cppRawString		String
-hi def link cppString		String
-hi def link cppNumber		Number
-hi def link cppFloat		Number
-hi def link cppModule		Include
-hi def link cppAttributeBracket	Special
-hi def link cppReflect		Operator
-hi def link cppSpliceBracket	Special
+hi def link cppString			String
+hi def link cppNumber			Number
+hi def link cppFloat			Number
+hi def link cppModule			Include
+hi def link cppAttributeBracket		Special
+hi def link cppReflect			Operator
+hi def link cppSpliceBracket		Special
 
 let b:current_syntax = "cpp"