text: /**
   * @param {string} value
   * @returns {RegExp}
   * */
  
  /**
   * @param {RegExp | string } re
   * @returns {string}
   */
  function source(re) {
    if (!re) return null;
    if (typeof re === "string") return re;
  
    return re.source;
  }
  
  /**
   * @param {RegExp | string } re
   * @returns {string}
   */
  function lookahead(re) {
    return concat('(?=', re, ')');
  }
  
  /**
   * @param {RegExp | string } re
   * @returns {string}
   */
  function optional(re) {
    return concat('(?:', re, ')?');
  }
  
  /**
   * @param {...(RegExp | string) } args
   * @returns {string}
   */
  function concat(...args) {
    const joined = args.map((x) => source(x)).join("");
    return joined;
  }
  
  /*
  Language: C++
  Category: common, system
  Website: https://isocpp.org
  */
  
  /** @type LanguageFn */
  function cpp(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 = '(?!struct)(' +
      DECLTYPE_AUTO_RE + '|' +
      optional(NAMESPACE_RE) +
      '[a-zA-Z_]\\w*' + optional(TEMPLATE_ARGUMENT_RE) +
    ')';
  
    const CPP_PRIMITIVE_TYPES = {
      className: 'type',
      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: {
        keyword:
          'if else elif endif define undef warning error line ' +
          'pragma _Pragma ifdef ifndef include'
      },
      contains: [
        {
          begin: /\\\n/,
          relevance: 0
        },
        hljs.inherit(STRINGS, {
          className: 'string'
        }),
        {
          className: 'string',
          begin: /<.*?>/
        },
        C_LINE_COMMENT_MODE,
        hljs.C_BLOCK_COMMENT_MODE
      ]
    };
  
    const TITLE_MODE = {
      className: 'title',
      begin: optional(NAMESPACE_RE) + hljs.IDENT_RE,
      relevance: 0
    };
  
    const FUNCTION_TITLE = optional(NAMESPACE_RE) + hljs.IDENT_RE + '\\s*\\(';
  
    // https://en.cppreference.com/w/cpp/keyword
    const RESERVED_KEYWORDS = [
      'alignas',
      'alignof',
      'and',
      'and_eq',
      'asm',
      'atomic_cancel',
      'atomic_commit',
      'atomic_noexcept',
      'auto',
      'bitand',
      'bitor',
      'break',
      'case',
      'catch',
      'class',
      'co_await',
      'co_return',
      'co_yield',
      'compl',
      'concept',
      'const',
      'const_cast|10',
      'consteval',
      'constexpr',
      'constinit',
      'continue',
      'decltype',
      'default',
      'delete',
      'do',
      'dynamic_cast|10',
      'else',
      'enum',
      'explicit',
      'export',
      'extern',
      'false',
      'final',
      'for',
      'friend',
      'goto',
      'if',
      'import',
      'inline',
      'module',
      'mutable',
      'namespace',
      'new',
      'noexcept',
      'not',
      'not_eq',
      'nullptr',
      'operator',
      'or',
      'or_eq',
      'override',
      'private',
      'protected',
      'public',
      'reflexpr',
      'register',
      'reinterpret_cast|10',
      'requires',
      'return',
      'signed',
      'sizeof',
      'static',
      'static_assert',
      'static_cast|10',
      'struct',
      'switch',
      'synchronized',
      'template',
      'this',
      'thread_local',
      'throw',
      'transaction_safe',
      'transaction_safe_dynamic',
      'true',
      'try',
      'typedef',
      'typeid',
      'typename',
      'union',
      'unsigned',
      'using',
      'virtual',
      'volatile',
      'while',
      'xor',
      'xor_eq,'
    ];
  
    // https://en.cppreference.com/w/cpp/keyword
    const RESERVED_TYPES = [
      'bool',
      'char',
      'char16_t',
      'char32_t',
      'char8_t',
      'double',
      'float',
      'int',
      'long',
      'short',
      'void',
      'wchar_t'
    ];
  
    const TYPE_HINTS = [
      'any',
      'auto_ptr',
      'barrier',
      'binary_semaphore',
      'bitset',
      'complex',
      'condition_variable',
      'condition_variable_any',
      'counting_semaphore',
      'deque',
      'false_type',
      'future',
      'imaginary',
      'initializer_list',
      'istringstream',
      'jthread',
      'latch',
      'lock_guard',
      'multimap',
      'multiset',
      'mutex',
      'optional',
      'ostringstream',
      'packaged_task',
      'pair',
      'promise',
      'priority_queue',
      'queue',
      'recursive_mutex',
      'recursive_timed_mutex',
      'scoped_lock',
      'set',
      'shared_future',
      'shared_lock',
      'shared_mutex',
      'shared_timed_mutex',
      'shared_ptr',
      'stack',
      'string_view',
      'stringstream',
      'timed_mutex',
      'thread',
      'true_type',
      'tuple',
      'unique_lock',
      'unique_ptr',
      'unordered_map',
      'unordered_multimap',
      'unordered_multiset',
      'unordered_set',
      'variant',
      'vector',
      'weak_ptr',
      'wstring',
      'wstring_view'
    ];
  
    const FUNCTION_HINTS = [
      'abort',
      'abs',
      'acos',
      'apply',
      'as_const',
      'asin',
      'atan',
      'atan2',
      'calloc',
      'ceil',
      'cerr',
      'cin',
      'clog',
      'cos',
      'cosh',
      'cout',
      'declval',
      'endl',
      'exchange',
      'exit',
      'exp',
      'fabs',
      'floor',
      'fmod',
      'forward',
      'fprintf',
      'fputs',
      'free',
      'frexp',
      'fscanf',
      'future',
      'invoke',
      'isalnum',
      'isalpha',
      'iscntrl',
      'isdigit',
      'isgraph',
      'islower',
      'isprint',
      'ispunct',
      'isspace',
      'isupper',
      'isxdigit',
      'labs',
      'launder',
      'ldexp',
      'log',
      'log10',
      'make_pair',
      'make_shared',
      'make_shared_for_overwrite',
      'make_tuple',
      'make_unique',
      'malloc',
      'memchr',
      'memcmp',
      'memcpy',
      'memset',
      'modf',
      'move',
      'pow',
      'printf',
      'putchar',
      'puts',
      'realloc',
      'scanf',
      'sin',
      'sinh',
      'snprintf',
      'sprintf',
      'sqrt',
      'sscanf',
      'std',
      'stderr',
      'stdin',
      'stdout',
      'strcat',
      'strchr',
      'strcmp',
      'strcpy',
      'strcspn',
      'strlen',
      'strncat',
      'strncmp',
      'strncpy',
      'strpbrk',
      'strrchr',
      'strspn',
      'strstr',
      'swap',
      'tan',
      'tanh',
      'terminate',
      'to_underlying',
      'tolower',
      'toupper',
      'vfprintf',
      'visit',
      'vprintf',
      'vsprintf'
    ];
  
    const LITERALS = [
      'NULL',
      'false',
      'nullopt',
      'nullptr',
      'true'
    ];
  
    // https://en.cppreference.com/w/cpp/keyword
    const BUILT_IN = [
      '_Pragma'
    ];
  
    const CPP_KEYWORDS = {
      type: RESERVED_TYPES,
      keyword: RESERVED_KEYWORDS,
      literal: LITERALS,
      built_in: BUILT_IN,
      _type_hints: TYPE_HINTS
    };
  
    const FUNCTION_DISPATCH = {
      className: 'function.dispatch',
      relevance: 0,
      keywords: {
        // Only for relevance, not highlighting.
        _hint: FUNCTION_HINTS
      },
      begin: concat(
        /\b/,
        /(?!decltype)/,
        /(?!if)/,
        /(?!for)/,
        /(?!while)/,
        hljs.IDENT_RE,
        lookahead(/(<[^<>]+>|)\s*\(/))
    };
  
    const EXPRESSION_CONTAINS = [
      FUNCTION_DISPATCH,
      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
        },
        // needed because we do not have look-behind on the below rule
        // to prevent it from grabbing the final : in a :: pair
        {
          begin: /::/,
          relevance: 0
        },
        // initializers
        {
          begin: /:/,
          endsWithParent: true,
          contains: [
            STRINGS,
            NUMBERS
          ]
        },
        // allow for multiple declarations, e.g.:
        // extern void f(int), g(char);
        {
          relevance: 0,
          match: /,/
        },
        {
          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: '</',
      classNameAliases: {
        'function.dispatch': 'built_in'
      },
      contains: [].concat(
        EXPRESSION_CONTEXT,
        FUNCTION_DECLARATION,
        FUNCTION_DISPATCH,
        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|tuple|optional|variant|function)\\s*<',
            end: '>',
            keywords: CPP_KEYWORDS,
            contains: [
              'self',
              CPP_PRIMITIVE_TYPES
            ]
          },
          {
            begin: hljs.IDENT_RE + '::',
            keywords: CPP_KEYWORDS
          },
          {
            match: [
              // extra complexity to deal with `enum class` and `enum struct`
              /\b(?:enum(?:\s+(?:class|struct))?|class|struct|union)/,
              /\s+/,
              /\w+/
            ],
            className: {
              1: 'keyword',
              3: 'title.class'
            }
          }
        ])
    };
  }
  
  export default cpp;