diff --git a/CHANGES.md b/CHANGES.md
index 390b397520..cd7cda8d5a 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -10,6 +10,12 @@ Language grammar improvements:
 - enh(swift) Improved highlighting for operator and precedencegroup declarations. (#2938) [Steven Van Impe][]
 - fix(xml) Support single-character namespaces. (#2957) [Jan Pilzer][]
 
+Grammar changes:
+
+- Deprecate `c-like`, though you should not be using it directly anyways.
+  - will be removed in v11.
+- `c` and `cpp` are now wholly unique grammars that will diverge over time
+
 Parser:
 
 - allow `keywords` to be an array of strings [Josh Goebel][]
diff --git a/src/languages/c-like.js b/src/languages/c-like.js
index fed736bc9c..88a3d988eb 100644
--- a/src/languages/c-like.js
+++ b/src/languages/c-like.js
@@ -1,293 +1,46 @@
 /*
-Language: C-like foundation grammar for C/C++ grammars
+Language: C-like (deprecated, use C and C++ instead)
 Author: Ivan Sagalaev <maniac@softwaremaniacs.org>
 Contributors: Evgeny Stepanischev <imbolk@gmail.com>, Zaven Muradyan <megalivoithos@gmail.com>, Roel Deckers <admin@codingcat.nl>, Sam Wu <samsam2310@gmail.com>, Jordi Petit <jordi.petit@gmail.com>, Pieter Vantorre <pietervantorre@gmail.com>, Google Inc. (David Benjamin) <davidben@google.com>
 */
 
-/* In the future the intention is to split out the C/C++ grammars distinctly
-since they are separate languages.  They will likely share a common foundation
-though, and this file sets the groundwork for that - so that we get the breaking
-change in v10 and don't have to change the requirements again later.
+/*
+C and C++ have now been fully split into `c.js` and `cpp.js`.
+This file only exists for legacy purposes to support v10.
+TODO: Remove this in v11.
 
 See: https://github.com/highlightjs/highlight.js/issues/2146
 */
 
-import * as regex from '../lib/regex.js';
+import cPlusPlus from './cpp.js';
 
 /** @type LanguageFn */
 export default function(hljs) {
-  // added for historic reasons because `hljs.C_LINE_COMMENT_MODE` does
-  // not include such support nor can we be sure all the grammars depending
-  // on it would desire this behavior
-  const C_LINE_COMMENT_MODE = hljs.COMMENT('//', '$', {
-    contains: [
-      {
-        begin: /\\\n/
-      }
-    ]
-  });
-  const DECLTYPE_AUTO_RE = 'decltype\\(auto\\)';
-  const NAMESPACE_RE = '[a-zA-Z_]\\w*::';
-  const TEMPLATE_ARGUMENT_RE = '<[^<>]+>';
-  const FUNCTION_TYPE_RE = '(' +
-    DECLTYPE_AUTO_RE + '|' +
-    regex.optional(NAMESPACE_RE) +
-    '[a-zA-Z_]\\w*' + regex.optional(TEMPLATE_ARGUMENT_RE) +
-  ')';
-  const CPP_PRIMITIVE_TYPES = {
-    className: 'keyword',
-    begin: '\\b[a-z\\d_]*_t\\b'
-  };
-
-  // https://en.cppreference.com/w/cpp/language/escape
-  // \\ \x \xFF \u2837 \u00323747 \374
-  const CHARACTER_ESCAPES = '\\\\(x[0-9A-Fa-f]{2}|u[0-9A-Fa-f]{4,8}|[0-7]{3}|\\S)';
-  const STRINGS = {
-    className: 'string',
-    variants: [
-      {
-        begin: '(u8?|U|L)?"',
-        end: '"',
-        illegal: '\\n',
-        contains: [ hljs.BACKSLASH_ESCAPE ]
-      },
-      {
-        begin: '(u8?|U|L)?\'(' + CHARACTER_ESCAPES + "|.)",
-        end: '\'',
-        illegal: '.'
-      },
-      hljs.END_SAME_AS_BEGIN({
-        begin: /(?:u8?|U|L)?R"([^()\\ ]{0,16})\(/,
-        end: /\)([^()\\ ]{0,16})"/
-      })
-    ]
-  };
-
-  const NUMBERS = {
-    className: 'number',
-    variants: [
-      {
-        begin: '\\b(0b[01\']+)'
-      },
-      {
-        begin: '(-?)\\b([\\d\']+(\\.[\\d\']*)?|\\.[\\d\']+)((ll|LL|l|L)(u|U)?|(u|U)(ll|LL|l|L)?|f|F|b|B)'
-      },
-      {
-        begin: '(-?)(\\b0[xX][a-fA-F0-9\']+|(\\b[\\d\']+(\\.[\\d\']*)?|\\.[\\d\']+)([eE][-+]?[\\d\']+)?)'
-      }
-    ],
-    relevance: 0
-  };
-
-  const PREPROCESSOR = {
-    className: 'meta',
-    begin: /#\s*[a-z]+\b/,
-    end: /$/,
-    keywords: {
-      'meta-keyword':
-        'if else elif endif define undef warning error line ' +
-        'pragma _Pragma ifdef ifndef include'
-    },
-    contains: [
-      {
-        begin: /\\\n/,
-        relevance: 0
-      },
-      hljs.inherit(STRINGS, {
-        className: 'meta-string'
-      }),
-      {
-        className: 'meta-string',
-        begin: /<.*?>/,
-        end: /$/,
-        illegal: '\\n'
-      },
-      C_LINE_COMMENT_MODE,
-      hljs.C_BLOCK_COMMENT_MODE
-    ]
-  };
+  const lang = cPlusPlus(hljs);
 
-  const TITLE_MODE = {
-    className: 'title',
-    begin: regex.optional(NAMESPACE_RE) + hljs.IDENT_RE,
-    relevance: 0
-  };
-
-  const FUNCTION_TITLE = regex.optional(NAMESPACE_RE) + hljs.IDENT_RE + '\\s*\\(';
-
-  const CPP_KEYWORDS = {
-    keyword: 'int float while private char char8_t char16_t char32_t catch import module export virtual operator sizeof ' +
-      'dynamic_cast|10 typedef const_cast|10 const for static_cast|10 union namespace ' +
-      'unsigned long volatile static protected bool template mutable if public friend ' +
-      'do goto auto void enum else break extern using asm case typeid wchar_t ' +
-      'short reinterpret_cast|10 default double register explicit signed typename try this ' +
-      'switch continue inline delete alignas alignof constexpr consteval constinit decltype ' +
-      'concept co_await co_return co_yield requires ' +
-      'noexcept static_assert thread_local restrict final override ' +
-      'atomic_bool atomic_char atomic_schar ' +
-      'atomic_uchar atomic_short atomic_ushort atomic_int atomic_uint atomic_long atomic_ulong atomic_llong ' +
-      'atomic_ullong new throw return ' +
-      'and and_eq bitand bitor compl not not_eq or or_eq xor xor_eq',
-    built_in: 'std string wstring cin cout cerr clog stdin stdout stderr stringstream istringstream ostringstream ' +
-      'auto_ptr deque list queue stack vector map set pair bitset multiset multimap unordered_set ' +
-      'unordered_map unordered_multiset unordered_multimap priority_queue make_pair array shared_ptr abort terminate abs acos ' +
-      'asin atan2 atan calloc ceil cosh cos exit exp fabs floor fmod fprintf fputs free frexp ' +
-      'fscanf future isalnum isalpha iscntrl isdigit isgraph islower isprint ispunct isspace isupper ' +
-      'isxdigit tolower toupper labs ldexp log10 log malloc realloc memchr memcmp memcpy memset modf pow ' +
-      'printf putchar puts scanf sinh sin snprintf sprintf sqrt sscanf strcat strchr strcmp ' +
-      'strcpy strcspn strlen strncat strncmp strncpy strpbrk strrchr strspn strstr tanh tan ' +
-      'vfprintf vprintf vsprintf endl initializer_list unique_ptr _Bool complex _Complex imaginary _Imaginary',
-    literal: 'true false nullptr NULL'
-  };
+  const C_ALIASES = [
+    "c",
+    "h"
+  ];
 
-  const EXPRESSION_CONTAINS = [
-    PREPROCESSOR,
-    CPP_PRIMITIVE_TYPES,
-    C_LINE_COMMENT_MODE,
-    hljs.C_BLOCK_COMMENT_MODE,
-    NUMBERS,
-    STRINGS
+  const CPP_ALIASES = [
+    'cc',
+    'c++',
+    'h++',
+    'hpp',
+    'hh',
+    'hxx',
+    'cxx'
   ];
 
-  const EXPRESSION_CONTEXT = {
-    // This mode covers expression context where we can't expect a function
-    // definition and shouldn't highlight anything that looks like one:
-    // `return some()`, `else if()`, `(x*sum(1, 2))`
-    variants: [
-      {
-        begin: /=/,
-        end: /;/
-      },
-      {
-        begin: /\(/,
-        end: /\)/
-      },
-      {
-        beginKeywords: 'new throw return else',
-        end: /;/
-      }
-    ],
-    keywords: CPP_KEYWORDS,
-    contains: EXPRESSION_CONTAINS.concat([
-      {
-        begin: /\(/,
-        end: /\)/,
-        keywords: CPP_KEYWORDS,
-        contains: EXPRESSION_CONTAINS.concat([ 'self' ]),
-        relevance: 0
-      }
-    ]),
-    relevance: 0
-  };
+  lang.disableAutodetect = true;
+  lang.aliases = [];
+  // support users only loading c-like (legacy)
+  if (!hljs.getLanguage("c")) lang.aliases.push(...C_ALIASES);
+  if (!hljs.getLanguage("cpp")) lang.aliases.push(...CPP_ALIASES);
 
-  const FUNCTION_DECLARATION = {
-    className: 'function',
-    begin: '(' + FUNCTION_TYPE_RE + '[\\*&\\s]+)+' + FUNCTION_TITLE,
-    returnBegin: true,
-    end: /[{;=]/,
-    excludeEnd: true,
-    keywords: CPP_KEYWORDS,
-    illegal: /[^\w\s\*&:<>.]/,
-    contains: [
-      { // to prevent it from being confused as the function title
-        begin: DECLTYPE_AUTO_RE,
-        keywords: CPP_KEYWORDS,
-        relevance: 0
-      },
-      {
-        begin: FUNCTION_TITLE,
-        returnBegin: true,
-        contains: [ TITLE_MODE ],
-        relevance: 0
-      },
-      {
-        className: 'params',
-        begin: /\(/,
-        end: /\)/,
-        keywords: CPP_KEYWORDS,
-        relevance: 0,
-        contains: [
-          C_LINE_COMMENT_MODE,
-          hljs.C_BLOCK_COMMENT_MODE,
-          STRINGS,
-          NUMBERS,
-          CPP_PRIMITIVE_TYPES,
-          // Count matching parentheses.
-          {
-            begin: /\(/,
-            end: /\)/,
-            keywords: CPP_KEYWORDS,
-            relevance: 0,
-            contains: [
-              'self',
-              C_LINE_COMMENT_MODE,
-              hljs.C_BLOCK_COMMENT_MODE,
-              STRINGS,
-              NUMBERS,
-              CPP_PRIMITIVE_TYPES
-            ]
-          }
-        ]
-      },
-      CPP_PRIMITIVE_TYPES,
-      C_LINE_COMMENT_MODE,
-      hljs.C_BLOCK_COMMENT_MODE,
-      PREPROCESSOR
-    ]
-  };
+  // if c and cpp are loaded after then they will reclaim these
+  // aliases for themselves
 
-  return {
-    aliases: [
-      'c',
-      'cc',
-      'h',
-      'c++',
-      'h++',
-      'hpp',
-      'hh',
-      'hxx',
-      'cxx'
-    ],
-    keywords: CPP_KEYWORDS,
-    // the base c-like language will NEVER be auto-detected, rather the
-    // derivitives: c, c++, arduino turn auto-detect back on for themselves
-    disableAutodetect: true,
-    illegal: '</',
-    contains: [].concat(
-      EXPRESSION_CONTEXT,
-      FUNCTION_DECLARATION,
-      EXPRESSION_CONTAINS,
-      [
-        PREPROCESSOR,
-        { // containers: ie, `vector <int> rooms (9);`
-          begin: '\\b(deque|list|queue|priority_queue|pair|stack|vector|map|set|bitset|multiset|multimap|unordered_map|unordered_set|unordered_multiset|unordered_multimap|array)\\s*<',
-          end: '>',
-          keywords: CPP_KEYWORDS,
-          contains: [
-            'self',
-            CPP_PRIMITIVE_TYPES
-          ]
-        },
-        {
-          begin: hljs.IDENT_RE + '::',
-          keywords: CPP_KEYWORDS
-        },
-        {
-          className: 'class',
-          beginKeywords: 'enum class struct union',
-          end: /[{;:<>=]/,
-          contains: [
-            {
-              beginKeywords: "final class struct"
-            },
-            hljs.TITLE_MODE
-          ]
-        }
-      ]),
-    exports: {
-      preprocessor: PREPROCESSOR,
-      strings: STRINGS,
-      keywords: CPP_KEYWORDS
-    }
-  };
+  return lang;
 }
diff --git a/src/languages/c.js b/src/languages/c.js
index 1ace9d497d..6bbf740095 100644
--- a/src/languages/c.js
+++ b/src/languages/c.js
@@ -4,19 +4,276 @@ Category: common, system
 Website: https://en.wikipedia.org/wiki/C_(programming_language)
 */
 
-import cLike from './c-like.js';
+import * as regex from '../lib/regex.js';
 
 /** @type LanguageFn */
 export default function(hljs) {
-  const lang = cLike(hljs);
-  // Until C is actually different than C++ there is no reason to auto-detect C
-  // as it's own language since it would just fail auto-detect testing or
-  // simply match with C++.
-  //
-  // See further comments in c-like.js.
-
-  // lang.disableAutodetect = false;
-  lang.name = 'C';
-  lang.aliases = ['c', 'h'];
-  return lang;
+  // added for historic reasons because `hljs.C_LINE_COMMENT_MODE` does
+  // not include such support nor can we be sure all the grammars depending
+  // on it would desire this behavior
+  const C_LINE_COMMENT_MODE = hljs.COMMENT('//', '$', {
+    contains: [
+      {
+        begin: /\\\n/
+      }
+    ]
+  });
+  const DECLTYPE_AUTO_RE = 'decltype\\(auto\\)';
+  const NAMESPACE_RE = '[a-zA-Z_]\\w*::';
+  const TEMPLATE_ARGUMENT_RE = '<[^<>]+>';
+  const FUNCTION_TYPE_RE = '(' +
+    DECLTYPE_AUTO_RE + '|' +
+    regex.optional(NAMESPACE_RE) +
+    '[a-zA-Z_]\\w*' + regex.optional(TEMPLATE_ARGUMENT_RE) +
+  ')';
+  const CPP_PRIMITIVE_TYPES = {
+    className: 'keyword',
+    begin: '\\b[a-z\\d_]*_t\\b'
+  };
+
+  // https://en.cppreference.com/w/cpp/language/escape
+  // \\ \x \xFF \u2837 \u00323747 \374
+  const CHARACTER_ESCAPES = '\\\\(x[0-9A-Fa-f]{2}|u[0-9A-Fa-f]{4,8}|[0-7]{3}|\\S)';
+  const STRINGS = {
+    className: 'string',
+    variants: [
+      {
+        begin: '(u8?|U|L)?"',
+        end: '"',
+        illegal: '\\n',
+        contains: [ hljs.BACKSLASH_ESCAPE ]
+      },
+      {
+        begin: '(u8?|U|L)?\'(' + CHARACTER_ESCAPES + "|.)",
+        end: '\'',
+        illegal: '.'
+      },
+      hljs.END_SAME_AS_BEGIN({
+        begin: /(?:u8?|U|L)?R"([^()\\ ]{0,16})\(/,
+        end: /\)([^()\\ ]{0,16})"/
+      })
+    ]
+  };
+
+  const NUMBERS = {
+    className: 'number',
+    variants: [
+      {
+        begin: '\\b(0b[01\']+)'
+      },
+      {
+        begin: '(-?)\\b([\\d\']+(\\.[\\d\']*)?|\\.[\\d\']+)((ll|LL|l|L)(u|U)?|(u|U)(ll|LL|l|L)?|f|F|b|B)'
+      },
+      {
+        begin: '(-?)(\\b0[xX][a-fA-F0-9\']+|(\\b[\\d\']+(\\.[\\d\']*)?|\\.[\\d\']+)([eE][-+]?[\\d\']+)?)'
+      }
+    ],
+    relevance: 0
+  };
+
+  const PREPROCESSOR = {
+    className: 'meta',
+    begin: /#\s*[a-z]+\b/,
+    end: /$/,
+    keywords: {
+      'meta-keyword':
+        'if else elif endif define undef warning error line ' +
+        'pragma _Pragma ifdef ifndef include'
+    },
+    contains: [
+      {
+        begin: /\\\n/,
+        relevance: 0
+      },
+      hljs.inherit(STRINGS, {
+        className: 'meta-string'
+      }),
+      {
+        className: 'meta-string',
+        begin: /<.*?>/,
+        end: /$/,
+        illegal: '\\n'
+      },
+      C_LINE_COMMENT_MODE,
+      hljs.C_BLOCK_COMMENT_MODE
+    ]
+  };
+
+  const TITLE_MODE = {
+    className: 'title',
+    begin: regex.optional(NAMESPACE_RE) + hljs.IDENT_RE,
+    relevance: 0
+  };
+
+  const FUNCTION_TITLE = regex.optional(NAMESPACE_RE) + hljs.IDENT_RE + '\\s*\\(';
+
+  const CPP_KEYWORDS = {
+    keyword: 'int float while private char char8_t char16_t char32_t catch import module export virtual operator sizeof ' +
+      'dynamic_cast|10 typedef const_cast|10 const for static_cast|10 union namespace ' +
+      'unsigned long volatile static protected bool template mutable if public friend ' +
+      'do goto auto void enum else break extern using asm case typeid wchar_t ' +
+      'short reinterpret_cast|10 default double register explicit signed typename try this ' +
+      'switch continue inline delete alignas alignof constexpr consteval constinit decltype ' +
+      'concept co_await co_return co_yield requires ' +
+      'noexcept static_assert thread_local restrict final override ' +
+      'atomic_bool atomic_char atomic_schar ' +
+      'atomic_uchar atomic_short atomic_ushort atomic_int atomic_uint atomic_long atomic_ulong atomic_llong ' +
+      'atomic_ullong new throw return ' +
+      'and and_eq bitand bitor compl not not_eq or or_eq xor xor_eq',
+    built_in: 'std string wstring cin cout cerr clog stdin stdout stderr stringstream istringstream ostringstream ' +
+      'auto_ptr deque list queue stack vector map set pair bitset multiset multimap unordered_set ' +
+      'unordered_map unordered_multiset unordered_multimap priority_queue make_pair array shared_ptr abort terminate abs acos ' +
+      'asin atan2 atan calloc ceil cosh cos exit exp fabs floor fmod fprintf fputs free frexp ' +
+      'fscanf future isalnum isalpha iscntrl isdigit isgraph islower isprint ispunct isspace isupper ' +
+      'isxdigit tolower toupper labs ldexp log10 log malloc realloc memchr memcmp memcpy memset modf pow ' +
+      'printf putchar puts scanf sinh sin snprintf sprintf sqrt sscanf strcat strchr strcmp ' +
+      'strcpy strcspn strlen strncat strncmp strncpy strpbrk strrchr strspn strstr tanh tan ' +
+      'vfprintf vprintf vsprintf endl initializer_list unique_ptr _Bool complex _Complex imaginary _Imaginary',
+    literal: 'true false nullptr NULL'
+  };
+
+  const EXPRESSION_CONTAINS = [
+    PREPROCESSOR,
+    CPP_PRIMITIVE_TYPES,
+    C_LINE_COMMENT_MODE,
+    hljs.C_BLOCK_COMMENT_MODE,
+    NUMBERS,
+    STRINGS
+  ];
+
+  const EXPRESSION_CONTEXT = {
+    // This mode covers expression context where we can't expect a function
+    // definition and shouldn't highlight anything that looks like one:
+    // `return some()`, `else if()`, `(x*sum(1, 2))`
+    variants: [
+      {
+        begin: /=/,
+        end: /;/
+      },
+      {
+        begin: /\(/,
+        end: /\)/
+      },
+      {
+        beginKeywords: 'new throw return else',
+        end: /;/
+      }
+    ],
+    keywords: CPP_KEYWORDS,
+    contains: EXPRESSION_CONTAINS.concat([
+      {
+        begin: /\(/,
+        end: /\)/,
+        keywords: CPP_KEYWORDS,
+        contains: EXPRESSION_CONTAINS.concat([ 'self' ]),
+        relevance: 0
+      }
+    ]),
+    relevance: 0
+  };
+
+  const FUNCTION_DECLARATION = {
+    className: 'function',
+    begin: '(' + FUNCTION_TYPE_RE + '[\\*&\\s]+)+' + FUNCTION_TITLE,
+    returnBegin: true,
+    end: /[{;=]/,
+    excludeEnd: true,
+    keywords: CPP_KEYWORDS,
+    illegal: /[^\w\s\*&:<>.]/,
+    contains: [
+      { // to prevent it from being confused as the function title
+        begin: DECLTYPE_AUTO_RE,
+        keywords: CPP_KEYWORDS,
+        relevance: 0
+      },
+      {
+        begin: FUNCTION_TITLE,
+        returnBegin: true,
+        contains: [ TITLE_MODE ],
+        relevance: 0
+      },
+      {
+        className: 'params',
+        begin: /\(/,
+        end: /\)/,
+        keywords: CPP_KEYWORDS,
+        relevance: 0,
+        contains: [
+          C_LINE_COMMENT_MODE,
+          hljs.C_BLOCK_COMMENT_MODE,
+          STRINGS,
+          NUMBERS,
+          CPP_PRIMITIVE_TYPES,
+          // Count matching parentheses.
+          {
+            begin: /\(/,
+            end: /\)/,
+            keywords: CPP_KEYWORDS,
+            relevance: 0,
+            contains: [
+              'self',
+              C_LINE_COMMENT_MODE,
+              hljs.C_BLOCK_COMMENT_MODE,
+              STRINGS,
+              NUMBERS,
+              CPP_PRIMITIVE_TYPES
+            ]
+          }
+        ]
+      },
+      CPP_PRIMITIVE_TYPES,
+      C_LINE_COMMENT_MODE,
+      hljs.C_BLOCK_COMMENT_MODE,
+      PREPROCESSOR
+    ]
+  };
+
+  return {
+    name: "C",
+    aliases: [
+      'c',
+      'h'
+    ],
+    keywords: CPP_KEYWORDS,
+    // Until differentiations are added between `c` and `cpp`, `c` will
+    // not be auto-detected to avoid auto-detect conflicts between C and C++
+    disableAutodetect: true,
+    illegal: '</',
+    contains: [].concat(
+      EXPRESSION_CONTEXT,
+      FUNCTION_DECLARATION,
+      EXPRESSION_CONTAINS,
+      [
+        PREPROCESSOR,
+        { // containers: ie, `vector <int> rooms (9);`
+          begin: '\\b(deque|list|queue|priority_queue|pair|stack|vector|map|set|bitset|multiset|multimap|unordered_map|unordered_set|unordered_multiset|unordered_multimap|array)\\s*<',
+          end: '>',
+          keywords: CPP_KEYWORDS,
+          contains: [
+            'self',
+            CPP_PRIMITIVE_TYPES
+          ]
+        },
+        {
+          begin: hljs.IDENT_RE + '::',
+          keywords: CPP_KEYWORDS
+        },
+        {
+          className: 'class',
+          beginKeywords: 'enum class struct union',
+          end: /[{;:<>=]/,
+          contains: [
+            {
+              beginKeywords: "final class struct"
+            },
+            hljs.TITLE_MODE
+          ]
+        }
+      ]),
+    exports: {
+      preprocessor: PREPROCESSOR,
+      strings: STRINGS,
+      keywords: CPP_KEYWORDS
+    }
+  };
 }
diff --git a/src/languages/cpp.js b/src/languages/cpp.js
index 7aab27f772..050a665ed4 100644
--- a/src/languages/cpp.js
+++ b/src/languages/cpp.js
@@ -4,14 +4,278 @@ Category: common, system
 Website: https://isocpp.org
 */
 
-import cLike from './c-like.js';
+import * as regex from '../lib/regex.js';
 
 /** @type LanguageFn */
 export default function(hljs) {
-  const lang = cLike(hljs);
-  // return auto-detection back on
-  lang.disableAutodetect = false;
-  lang.name = 'C++';
-  lang.aliases = ['cc', 'c++', 'h++', 'hpp', 'hh', 'hxx', 'cxx'];
-  return lang;
+  // added for historic reasons because `hljs.C_LINE_COMMENT_MODE` does
+  // not include such support nor can we be sure all the grammars depending
+  // on it would desire this behavior
+  const C_LINE_COMMENT_MODE = hljs.COMMENT('//', '$', {
+    contains: [
+      {
+        begin: /\\\n/
+      }
+    ]
+  });
+  const DECLTYPE_AUTO_RE = 'decltype\\(auto\\)';
+  const NAMESPACE_RE = '[a-zA-Z_]\\w*::';
+  const TEMPLATE_ARGUMENT_RE = '<[^<>]+>';
+  const FUNCTION_TYPE_RE = '(' +
+    DECLTYPE_AUTO_RE + '|' +
+    regex.optional(NAMESPACE_RE) +
+    '[a-zA-Z_]\\w*' + regex.optional(TEMPLATE_ARGUMENT_RE) +
+  ')';
+  const CPP_PRIMITIVE_TYPES = {
+    className: 'keyword',
+    begin: '\\b[a-z\\d_]*_t\\b'
+  };
+
+  // https://en.cppreference.com/w/cpp/language/escape
+  // \\ \x \xFF \u2837 \u00323747 \374
+  const CHARACTER_ESCAPES = '\\\\(x[0-9A-Fa-f]{2}|u[0-9A-Fa-f]{4,8}|[0-7]{3}|\\S)';
+  const STRINGS = {
+    className: 'string',
+    variants: [
+      {
+        begin: '(u8?|U|L)?"',
+        end: '"',
+        illegal: '\\n',
+        contains: [ hljs.BACKSLASH_ESCAPE ]
+      },
+      {
+        begin: '(u8?|U|L)?\'(' + CHARACTER_ESCAPES + "|.)",
+        end: '\'',
+        illegal: '.'
+      },
+      hljs.END_SAME_AS_BEGIN({
+        begin: /(?:u8?|U|L)?R"([^()\\ ]{0,16})\(/,
+        end: /\)([^()\\ ]{0,16})"/
+      })
+    ]
+  };
+
+  const NUMBERS = {
+    className: 'number',
+    variants: [
+      {
+        begin: '\\b(0b[01\']+)'
+      },
+      {
+        begin: '(-?)\\b([\\d\']+(\\.[\\d\']*)?|\\.[\\d\']+)((ll|LL|l|L)(u|U)?|(u|U)(ll|LL|l|L)?|f|F|b|B)'
+      },
+      {
+        begin: '(-?)(\\b0[xX][a-fA-F0-9\']+|(\\b[\\d\']+(\\.[\\d\']*)?|\\.[\\d\']+)([eE][-+]?[\\d\']+)?)'
+      }
+    ],
+    relevance: 0
+  };
+
+  const PREPROCESSOR = {
+    className: 'meta',
+    begin: /#\s*[a-z]+\b/,
+    end: /$/,
+    keywords: {
+      'meta-keyword':
+        'if else elif endif define undef warning error line ' +
+        'pragma _Pragma ifdef ifndef include'
+    },
+    contains: [
+      {
+        begin: /\\\n/,
+        relevance: 0
+      },
+      hljs.inherit(STRINGS, {
+        className: 'meta-string'
+      }),
+      {
+        className: 'meta-string',
+        begin: /<.*?>/,
+        end: /$/,
+        illegal: '\\n'
+      },
+      C_LINE_COMMENT_MODE,
+      hljs.C_BLOCK_COMMENT_MODE
+    ]
+  };
+
+  const TITLE_MODE = {
+    className: 'title',
+    begin: regex.optional(NAMESPACE_RE) + hljs.IDENT_RE,
+    relevance: 0
+  };
+
+  const FUNCTION_TITLE = regex.optional(NAMESPACE_RE) + hljs.IDENT_RE + '\\s*\\(';
+
+  const CPP_KEYWORDS = {
+    keyword: 'int float while private char char8_t char16_t char32_t catch import module export virtual operator sizeof ' +
+      'dynamic_cast|10 typedef const_cast|10 const for static_cast|10 union namespace ' +
+      'unsigned long volatile static protected bool template mutable if public friend ' +
+      'do goto auto void enum else break extern using asm case typeid wchar_t ' +
+      'short reinterpret_cast|10 default double register explicit signed typename try this ' +
+      'switch continue inline delete alignas alignof constexpr consteval constinit decltype ' +
+      'concept co_await co_return co_yield requires ' +
+      'noexcept static_assert thread_local restrict final override ' +
+      'atomic_bool atomic_char atomic_schar ' +
+      'atomic_uchar atomic_short atomic_ushort atomic_int atomic_uint atomic_long atomic_ulong atomic_llong ' +
+      'atomic_ullong new throw return ' +
+      'and and_eq bitand bitor compl not not_eq or or_eq xor xor_eq',
+    built_in: 'std string wstring cin cout cerr clog stdin stdout stderr stringstream istringstream ostringstream ' +
+      'auto_ptr deque list queue stack vector map set pair bitset multiset multimap unordered_set ' +
+      'unordered_map unordered_multiset unordered_multimap priority_queue make_pair array shared_ptr abort terminate abs acos ' +
+      'asin atan2 atan calloc ceil cosh cos exit exp fabs floor fmod fprintf fputs free frexp ' +
+      'fscanf future isalnum isalpha iscntrl isdigit isgraph islower isprint ispunct isspace isupper ' +
+      'isxdigit tolower toupper labs ldexp log10 log malloc realloc memchr memcmp memcpy memset modf pow ' +
+      'printf putchar puts scanf sinh sin snprintf sprintf sqrt sscanf strcat strchr strcmp ' +
+      'strcpy strcspn strlen strncat strncmp strncpy strpbrk strrchr strspn strstr tanh tan ' +
+      'vfprintf vprintf vsprintf endl initializer_list unique_ptr _Bool complex _Complex imaginary _Imaginary',
+    literal: 'true false nullptr NULL'
+  };
+
+  const EXPRESSION_CONTAINS = [
+    PREPROCESSOR,
+    CPP_PRIMITIVE_TYPES,
+    C_LINE_COMMENT_MODE,
+    hljs.C_BLOCK_COMMENT_MODE,
+    NUMBERS,
+    STRINGS
+  ];
+
+  const EXPRESSION_CONTEXT = {
+    // This mode covers expression context where we can't expect a function
+    // definition and shouldn't highlight anything that looks like one:
+    // `return some()`, `else if()`, `(x*sum(1, 2))`
+    variants: [
+      {
+        begin: /=/,
+        end: /;/
+      },
+      {
+        begin: /\(/,
+        end: /\)/
+      },
+      {
+        beginKeywords: 'new throw return else',
+        end: /;/
+      }
+    ],
+    keywords: CPP_KEYWORDS,
+    contains: EXPRESSION_CONTAINS.concat([
+      {
+        begin: /\(/,
+        end: /\)/,
+        keywords: CPP_KEYWORDS,
+        contains: EXPRESSION_CONTAINS.concat([ 'self' ]),
+        relevance: 0
+      }
+    ]),
+    relevance: 0
+  };
+
+  const FUNCTION_DECLARATION = {
+    className: 'function',
+    begin: '(' + FUNCTION_TYPE_RE + '[\\*&\\s]+)+' + FUNCTION_TITLE,
+    returnBegin: true,
+    end: /[{;=]/,
+    excludeEnd: true,
+    keywords: CPP_KEYWORDS,
+    illegal: /[^\w\s\*&:<>.]/,
+    contains: [
+      { // to prevent it from being confused as the function title
+        begin: DECLTYPE_AUTO_RE,
+        keywords: CPP_KEYWORDS,
+        relevance: 0
+      },
+      {
+        begin: FUNCTION_TITLE,
+        returnBegin: true,
+        contains: [ TITLE_MODE ],
+        relevance: 0
+      },
+      {
+        className: 'params',
+        begin: /\(/,
+        end: /\)/,
+        keywords: CPP_KEYWORDS,
+        relevance: 0,
+        contains: [
+          C_LINE_COMMENT_MODE,
+          hljs.C_BLOCK_COMMENT_MODE,
+          STRINGS,
+          NUMBERS,
+          CPP_PRIMITIVE_TYPES,
+          // Count matching parentheses.
+          {
+            begin: /\(/,
+            end: /\)/,
+            keywords: CPP_KEYWORDS,
+            relevance: 0,
+            contains: [
+              'self',
+              C_LINE_COMMENT_MODE,
+              hljs.C_BLOCK_COMMENT_MODE,
+              STRINGS,
+              NUMBERS,
+              CPP_PRIMITIVE_TYPES
+            ]
+          }
+        ]
+      },
+      CPP_PRIMITIVE_TYPES,
+      C_LINE_COMMENT_MODE,
+      hljs.C_BLOCK_COMMENT_MODE,
+      PREPROCESSOR
+    ]
+  };
+
+  return {
+    name: 'C++',
+    aliases: [
+      'cc',
+      'c++',
+      'h++',
+      'hpp',
+      'hh',
+      'hxx',
+      'cxx'
+    ],
+    keywords: CPP_KEYWORDS,
+    illegal: '</',
+    contains: [].concat(
+      EXPRESSION_CONTEXT,
+      FUNCTION_DECLARATION,
+      EXPRESSION_CONTAINS,
+      [
+        PREPROCESSOR,
+        { // containers: ie, `vector <int> rooms (9);`
+          begin: '\\b(deque|list|queue|priority_queue|pair|stack|vector|map|set|bitset|multiset|multimap|unordered_map|unordered_set|unordered_multiset|unordered_multimap|array)\\s*<',
+          end: '>',
+          keywords: CPP_KEYWORDS,
+          contains: [
+            'self',
+            CPP_PRIMITIVE_TYPES
+          ]
+        },
+        {
+          begin: hljs.IDENT_RE + '::',
+          keywords: CPP_KEYWORDS
+        },
+        {
+          className: 'class',
+          beginKeywords: 'enum class struct union',
+          end: /[{;:<>=]/,
+          contains: [
+            {
+              beginKeywords: "final class struct"
+            },
+            hljs.TITLE_MODE
+          ]
+        }
+      ]),
+    exports: {
+      preprocessor: PREPROCESSOR,
+      strings: STRINGS,
+      keywords: CPP_KEYWORDS
+    }
+  };
 }