\gramSec[gram.lex]{Lexical conventions} \begin{bnf} \nontermdef{hex-quad}\br hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit \end{bnf} \begin{bnf} \nontermdef{universal-character-name}\br \terminal{\textbackslash u} hex-quad\br \terminal{\textbackslash U} hex-quad hex-quad \end{bnf} \begin{bnf} \nontermdef{preprocessing-token}\br header-name\br import-keyword\br module-keyword\br export-keyword\br identifier\br pp-number\br character-literal\br user-defined-character-literal\br string-literal\br user-defined-string-literal\br preprocessing-op-or-punc\br \textnormal{each non-whitespace character that cannot be one of the above} \end{bnf} \begin{bnf} \nontermdef{token}\br identifier\br keyword\br literal\br operator-or-punctuator \end{bnf} \begin{bnf} \nontermdef{header-name}\br \terminal{<} h-char-sequence \terminal{>}\br \terminal{"} q-char-sequence \terminal{"} \end{bnf} \begin{bnf} \nontermdef{h-char-sequence}\br h-char\br h-char-sequence h-char \end{bnf} \begin{bnf} \nontermdef{h-char}\br \textnormal{any member of the source character set except new-line and \terminal{>}} \end{bnf} \begin{bnf} \nontermdef{q-char-sequence}\br q-char\br q-char-sequence q-char \end{bnf} \begin{bnf} \nontermdef{q-char}\br \textnormal{any member of the source character set except new-line and \terminal{"}} \end{bnf} \begin{bnf} \nontermdef{pp-number}\br digit\br \terminal{.} digit\br pp-number digit\br pp-number identifier-nondigit\br pp-number \terminal{'} digit\br pp-number \terminal{'} nondigit\br pp-number \terminal{e} sign\br pp-number \terminal{E} sign\br pp-number \terminal{p} sign\br pp-number \terminal{P} sign\br pp-number \terminal{.} \end{bnf} \begin{bnf} \nontermdef{identifier}\br identifier-nondigit\br identifier identifier-nondigit\br identifier digit \end{bnf} \begin{bnf} \nontermdef{identifier-nondigit}\br nondigit\br universal-character-name \end{bnf} \begin{bnf} \nontermdef{nondigit} \textnormal{one of}\br \terminal{a b c d e f g h i j k l m}\br \terminal{n o p q r s t u v w x y z}\br \terminal{A B C D E F G H I J K L M}\br \terminal{N O P Q R S T U V W X Y Z _} \end{bnf} \begin{bnf} \nontermdef{digit} \textnormal{one of}\br \terminal{0 1 2 3 4 5 6 7 8 9} \end{bnf} \begin{bnf} \nontermdef{keyword}\br \textnormal{any identifier listed in \tref{lex.key}}\br \grammarterm{import-keyword}\br \grammarterm{module-keyword}\br \grammarterm{export-keyword} \end{bnf} \begin{bnf} \nontermdef{preprocessing-op-or-punc}\br preprocessing-operator\br operator-or-punctuator \end{bnf} \begin{bnf} %% Ed. note: character protrusion would misalign various operators. \microtypesetup{protrusion=false}\obeyspaces \nontermdef{preprocessing-operator} \textnormal{one of}\br \terminal{\# \#\# \%: \%:\%:} \end{bnf} \begin{bnf} \microtypesetup{protrusion=false}\obeyspaces \nontermdef{operator-or-punctuator} \textnormal{one of}\br \terminal{\{ \} [ ] ( )}\br \terminal{<: :> <\% \%> ; : ...}\br \terminal{? :: . .* -> ->* \~}\br \terminal{! + - * / \% \caret{} \& |}\br \terminal{= += -= *= /= \%= \caret{}= \&= |=}\br \terminal{== != < > <= >= <=> \&\& ||}\br \terminal{<< >> <<= >>= ++ -- ,}\br \terminal{and or xor not bitand bitor compl}\br \terminal{and_eq or_eq xor_eq not_eq} \end{bnf} \begin{bnf} \nontermdef{literal}\br integer-literal\br character-literal\br floating-point-literal\br string-literal\br boolean-literal\br pointer-literal\br user-defined-literal \end{bnf} \begin{bnf} \nontermdef{integer-literal}\br binary-literal \opt{integer-suffix}\br octal-literal \opt{integer-suffix}\br decimal-literal \opt{integer-suffix}\br hexadecimal-literal \opt{integer-suffix} \end{bnf} \begin{bnf} \nontermdef{binary-literal}\br \terminal{0b} binary-digit\br \terminal{0B} binary-digit\br binary-literal \opt{\terminal{'}} binary-digit \end{bnf} \begin{bnf} \nontermdef{octal-literal}\br \terminal{0}\br octal-literal \opt{\terminal{'}} octal-digit \end{bnf} \begin{bnf} \nontermdef{decimal-literal}\br nonzero-digit\br decimal-literal \opt{\terminal{'}} digit \end{bnf} \begin{bnf} \nontermdef{hexadecimal-literal}\br hexadecimal-prefix hexadecimal-digit-sequence \end{bnf} \begin{bnf} \nontermdef{binary-digit} \textnormal{one of}\br \terminal{0 1} \end{bnf} \begin{bnf} \nontermdef{octal-digit} \textnormal{one of}\br \terminal{0 1 2 3 4 5 6 7} \end{bnf} \begin{bnf} \nontermdef{nonzero-digit} \textnormal{one of}\br \terminal{1 2 3 4 5 6 7 8 9} \end{bnf} \begin{bnf} \nontermdef{hexadecimal-prefix} \textnormal{one of}\br \terminal{0x 0X} \end{bnf} \begin{bnf} \nontermdef{hexadecimal-digit-sequence}\br hexadecimal-digit\br hexadecimal-digit-sequence \opt{\terminal{'}} hexadecimal-digit \end{bnf} \begin{bnf} \nontermdef{hexadecimal-digit} \textnormal{one of}\br \terminal{0 1 2 3 4 5 6 7 8 9}\br \terminal{a b c d e f}\br \terminal{A B C D E F} \end{bnf} \begin{bnf} \nontermdef{integer-suffix}\br unsigned-suffix \opt{long-suffix} \br unsigned-suffix \opt{long-long-suffix} \br unsigned-suffix \opt{size-suffix} \br long-suffix \opt{unsigned-suffix} \br long-long-suffix \opt{unsigned-suffix} \br size-suffix \opt{unsigned-suffix} \end{bnf} \begin{bnf} \nontermdef{unsigned-suffix} \textnormal{one of}\br \terminal{u U} \end{bnf} \begin{bnf} \nontermdef{long-suffix} \textnormal{one of}\br \terminal{l L} \end{bnf} \begin{bnf} \nontermdef{long-long-suffix} \textnormal{one of}\br \terminal{ll LL} \end{bnf} \begin{bnf} \nontermdef{size-suffix} \textnormal{one of}\br \terminal{z Z} \end{bnf} \begin{bnf} \nontermdef{character-literal}\br \opt{encoding-prefix} \terminal{'} c-char-sequence \terminal{'} \end{bnf} \begin{bnf} \nontermdef{encoding-prefix} \textnormal{one of}\br \terminal{u8}\quad\terminal{u}\quad\terminal{U}\quad\terminal{L} \end{bnf} \begin{bnf} \nontermdef{c-char-sequence}\br c-char\br c-char-sequence c-char \end{bnf} \begin{bnf} \nontermdef{c-char}\br basic-c-char\br escape-sequence\br universal-character-name \end{bnf} \begin{bnf} \nontermdef{basic-c-char}\br \textnormal{any member of the basic source character set except the single-quote \terminal{'}, backslash \terminal{\textbackslash}, or new-line character} \end{bnf} \begin{bnf} \nontermdef{escape-sequence}\br simple-escape-sequence\br numeric-escape-sequence\br conditional-escape-sequence \end{bnf} \begin{bnf} \nontermdef{simple-escape-sequence}\br \terminal{\textbackslash} simple-escape-sequence-char \end{bnf} \begin{bnf} \nontermdef{simple-escape-sequence-char} \textnormal{one of}\br \terminal{' " ? \textbackslash{} a b f n r t v} \end{bnf} \begin{bnf} \nontermdef{numeric-escape-sequence}\br octal-escape-sequence\br hexadecimal-escape-sequence \end{bnf} \begin{bnf} \nontermdef{octal-escape-sequence}\br \terminal{\textbackslash} octal-digit\br \terminal{\textbackslash} octal-digit octal-digit\br \terminal{\textbackslash} octal-digit octal-digit octal-digit \end{bnf} \begin{bnf} \nontermdef{hexadecimal-escape-sequence}\br \terminal{\textbackslash x} hexadecimal-digit\br hexadecimal-escape-sequence hexadecimal-digit \end{bnf} \begin{bnf} \nontermdef{conditional-escape-sequence}\br \terminal{\textbackslash} conditional-escape-sequence-char \end{bnf} \begin{bnf} \nontermdef{conditional-escape-sequence-char}\br \textnormal{any member of the basic source character set that is not an} octal-digit\textnormal{, a} simple-escape-sequence-char\textnormal{, or the characters \terminal{u}, \terminal{U}, or \terminal{x}} \end{bnf} \begin{bnf} \nontermdef{floating-point-literal}\br decimal-floating-point-literal\br hexadecimal-floating-point-literal \end{bnf} \begin{bnf} \nontermdef{decimal-floating-point-literal}\br fractional-constant \opt{exponent-part} \opt{floating-point-suffix}\br digit-sequence exponent-part \opt{floating-point-suffix} \end{bnf} \begin{bnf} \nontermdef{hexadecimal-floating-point-literal}\br hexadecimal-prefix hexadecimal-fractional-constant binary-exponent-part \opt{floating-point-suffix}\br hexadecimal-prefix hexadecimal-digit-sequence binary-exponent-part \opt{floating-point-suffix} \end{bnf} \begin{bnf} \nontermdef{fractional-constant}\br \opt{digit-sequence} \terminal{.} digit-sequence\br digit-sequence \terminal{.} \end{bnf} \begin{bnf} \nontermdef{hexadecimal-fractional-constant}\br \opt{hexadecimal-digit-sequence} \terminal{.} hexadecimal-digit-sequence\br hexadecimal-digit-sequence \terminal{.} \end{bnf} \begin{bnf} \nontermdef{exponent-part}\br \terminal{e} \opt{sign} digit-sequence\br \terminal{E} \opt{sign} digit-sequence \end{bnf} \begin{bnf} \nontermdef{binary-exponent-part}\br \terminal{p} \opt{sign} digit-sequence\br \terminal{P} \opt{sign} digit-sequence \end{bnf} \begin{bnf} \nontermdef{sign} \textnormal{one of}\br \terminal{+ -} \end{bnf} \begin{bnf} \nontermdef{digit-sequence}\br digit\br digit-sequence \opt{\terminal{'}} digit \end{bnf} \begin{bnf} \nontermdef{floating-point-suffix} \textnormal{one of}\br \terminal{f l F L} \end{bnf} \begin{bnf} \nontermdef{string-literal}\br \opt{encoding-prefix} \terminal{"} \opt{s-char-sequence} \terminal{"}\br \opt{encoding-prefix} \terminal{R} raw-string \end{bnf} \begin{bnf} \nontermdef{s-char-sequence}\br s-char\br s-char-sequence s-char \end{bnf} \begin{bnf} \nontermdef{s-char}\br basic-s-char\br escape-sequence\br universal-character-name \end{bnf} \begin{bnf} \nontermdef{basic-s-char}\br \textnormal{any member of the basic source character set except the double-quote \terminal{"}, backslash \terminal{\textbackslash}, or new-line character} \end{bnf} \begin{bnf} \nontermdef{raw-string}\br \terminal{"} \opt{d-char-sequence} \terminal{(} \opt{r-char-sequence} \terminal{)} \opt{d-char-sequence} \terminal{"} \end{bnf} \begin{bnf} \nontermdef{r-char-sequence}\br r-char\br r-char-sequence r-char \end{bnf} \begin{bnf} \nontermdef{r-char}\br \textnormal{any member of the source character set, except a right parenthesis \terminal{)} followed by}\br \bnfindent\textnormal{the initial \grammarterm{d-char-sequence} (which may be empty) followed by a double quote \terminal{"}.} \end{bnf} \begin{bnf} \nontermdef{d-char-sequence}\br d-char\br d-char-sequence d-char \end{bnf} \begin{bnf} \nontermdef{d-char}\br \textnormal{any member of the basic source character set except:}\br \bnfindent\textnormal{space, the left parenthesis \terminal{(}, the right parenthesis \terminal{)}, the backslash \terminal{\textbackslash}, and the control characters}\br \bnfindent\textnormal{representing horizontal tab, vertical tab, form feed, and newline.} \end{bnf} \begin{bnf} \nontermdef{boolean-literal}\br \terminal{false}\br \terminal{true} \end{bnf} \begin{bnf} \nontermdef{pointer-literal}\br \terminal{nullptr} \end{bnf} \begin{bnf} \nontermdef{user-defined-literal}\br user-defined-integer-literal\br user-defined-floating-point-literal\br user-defined-string-literal\br user-defined-character-literal \end{bnf} \begin{bnf} \nontermdef{user-defined-integer-literal}\br decimal-literal ud-suffix\br octal-literal ud-suffix\br hexadecimal-literal ud-suffix\br binary-literal ud-suffix \end{bnf} \begin{bnf} \nontermdef{user-defined-floating-point-literal}\br fractional-constant \opt{exponent-part} ud-suffix\br digit-sequence exponent-part ud-suffix\br hexadecimal-prefix hexadecimal-fractional-constant binary-exponent-part ud-suffix\br hexadecimal-prefix hexadecimal-digit-sequence binary-exponent-part ud-suffix \end{bnf} \begin{bnf} \nontermdef{user-defined-string-literal}\br string-literal ud-suffix \end{bnf} \begin{bnf} \nontermdef{user-defined-character-literal}\br character-literal ud-suffix \end{bnf} \begin{bnf} \nontermdef{ud-suffix}\br identifier \end{bnf} \gramSec[gram.basic]{Basics} \begin{bnf} \nontermdef{translation-unit}\br \opt{declaration-seq}\br \opt{global-module-fragment} module-declaration \opt{declaration-seq} \opt{private-module-fragment} \end{bnf} \gramSec[gram.expr]{Expressions} \begin{bnf} \nontermdef{primary-expression}\br literal\br \keyword{this}\br \terminal{(} expression \terminal{)}\br id-expression\br lambda-expression\br fold-expression\br requires-expression \end{bnf} \begin{bnf} \nontermdef{id-expression}\br unqualified-id\br qualified-id \end{bnf} \begin{bnf} \nontermdef{unqualified-id}\br identifier\br operator-function-id\br conversion-function-id\br literal-operator-id\br \terminal{\~} type-name\br \terminal{\~} decltype-specifier\br template-id \end{bnf} \begin{bnf} \nontermdef{qualified-id}\br nested-name-specifier \opt{\keyword{template}} unqualified-id \end{bnf} \begin{bnf} \nontermdef{nested-name-specifier}\br \terminal{::}\br type-name \terminal{::}\br namespace-name \terminal{::}\br decltype-specifier \terminal{::}\br nested-name-specifier identifier \terminal{::}\br nested-name-specifier \opt{\keyword{template}} simple-template-id \terminal{::} \end{bnf} \begin{bnf} \nontermdef{lambda-expression}\br lambda-introducer \opt{lambda-declarator} compound-statement\br lambda-introducer \terminal{<} template-parameter-list \terminal{>} \opt{requires-clause} \opt{lambda-declarator} compound-statement \end{bnf} \begin{bnf} \nontermdef{lambda-introducer}\br \terminal{[} \opt{lambda-capture} \terminal{]} \end{bnf} \begin{bnf} \nontermdef{lambda-declarator}\br \terminal{(} parameter-declaration-clause \terminal{)} \opt{decl-specifier-seq}\br \bnfindent\opt{noexcept-specifier} \opt{attribute-specifier-seq} \opt{trailing-return-type} \opt{requires-clause} \end{bnf} \begin{bnf} \nontermdef{lambda-capture}\br capture-default\br capture-list\br capture-default \terminal{,} capture-list \end{bnf} \begin{bnf} \nontermdef{capture-default}\br \terminal{\&}\br \terminal{=} \end{bnf} \begin{bnf} \nontermdef{capture-list}\br capture\br capture-list \terminal{,} capture \end{bnf} \begin{bnf} \nontermdef{capture}\br simple-capture\br init-capture \end{bnf} \begin{bnf} \nontermdef{simple-capture}\br identifier \opt{\terminal{...}}\br \terminal{\&} identifier \opt{\terminal{...}}\br \keyword{this}\br \terminal{*} \terminal{this} \end{bnf} \begin{bnf} \nontermdef{init-capture}\br \opt{\terminal{...}} identifier initializer\br \terminal{\&} \opt{\terminal{...}} identifier initializer \end{bnf} \begin{bnf} \nontermdef{fold-expression}\br \terminal{(} cast-expression fold-operator \terminal{...} \terminal{)}\br \terminal{(} \terminal{...} fold-operator cast-expression \terminal{)}\br \terminal{(} cast-expression fold-operator \terminal{...} fold-operator cast-expression \terminal{)} \end{bnf} \begin{bnf} %% Ed. note: character protrusion would misalign operators with leading `-`. \microtypesetup{protrusion=false} \nontermdef{fold-operator} \textnormal{one of}\br \terminal{+ }\quad\terminal{- }\quad\terminal{* }\quad\terminal{/ }\quad\terminal{\% }\quad\terminal{\caret{} }\quad\terminal{\& }\quad\terminal{| }\quad\terminal{<< }\quad\terminal{>> }\br \terminal{+=}\quad\terminal{-=}\quad\terminal{*=}\quad\terminal{/=}\quad\terminal{\%=}\quad\terminal{\caret=}\quad\terminal{\&=}\quad\terminal{|=}\quad\terminal{<<=}\quad\terminal{>>=}\quad\terminal{=}\br \terminal{==}\quad\terminal{!=}\quad\terminal{< }\quad\terminal{> }\quad\terminal{<=}\quad\terminal{>=}\quad\terminal{\&\&}\quad\terminal{||}\quad\terminal{, }\quad\terminal{.* }\quad\terminal{->*} \end{bnf} \begin{bnf} \nontermdef{requires-expression}\br \keyword{requires} \opt{requirement-parameter-list} requirement-body \end{bnf} \begin{bnf} \nontermdef{requirement-parameter-list}\br \terminal{(} parameter-declaration-clause \terminal{)} \end{bnf} \begin{bnf} \nontermdef{requirement-body}\br \terminal{\{} requirement-seq \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{requirement-seq}\br requirement\br requirement-seq requirement \end{bnf} \begin{bnf} \nontermdef{requirement}\br simple-requirement\br type-requirement\br compound-requirement\br nested-requirement \end{bnf} \begin{bnf} \nontermdef{simple-requirement}\br expression \terminal{;} \end{bnf} \begin{bnf} \nontermdef{type-requirement}\br \keyword{typename} \opt{nested-name-specifier} type-name \terminal{;} \end{bnf} \begin{bnf} \nontermdef{compound-requirement}\br \terminal{\{} expression \terminal{\}} \opt{\keyword{noexcept}} \opt{return-type-requirement} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{return-type-requirement}\br \terminal{->} type-constraint \end{bnf} \begin{bnf} \nontermdef{nested-requirement}\br \keyword{requires} constraint-expression \terminal{;} \end{bnf} \begin{bnf} \nontermdef{postfix-expression}\br primary-expression\br postfix-expression \terminal{[} expr-or-braced-init-list \terminal{]}\br postfix-expression \terminal{(} \opt{expression-list} \terminal{)}\br simple-type-specifier \terminal{(} \opt{expression-list} \terminal{)}\br typename-specifier \terminal{(} \opt{expression-list} \terminal{)}\br simple-type-specifier braced-init-list\br typename-specifier braced-init-list\br postfix-expression \terminal{.} \opt{\terminal{template}} id-expression\br postfix-expression \terminal{->} \opt{\terminal{template}} id-expression\br postfix-expression \terminal{++}\br postfix-expression \terminal{--}\br \keyword{dynamic_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br \keyword{static_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br \keyword{reinterpret_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br \keyword{const_cast} \terminal{<} type-id \terminal{>} \terminal{(} expression \terminal{)}\br \keyword{typeid} \terminal{(} expression \terminal{)}\br \keyword{typeid} \terminal{(} type-id \terminal{)} \end{bnf} \begin{bnf} \nontermdef{expression-list}\br initializer-list \end{bnf} \begin{bnf} \nontermdef{unary-expression}\br postfix-expression\br unary-operator cast-expression\br \terminal{++} cast-expression\br \terminal{--} cast-expression\br await-expression\br \keyword{sizeof} unary-expression\br \keyword{sizeof} \terminal{(} type-id \terminal{)}\br \keyword{sizeof} \terminal{...} \terminal{(} identifier \terminal{)}\br \keyword{alignof} \terminal{(} type-id \terminal{)}\br noexcept-expression\br new-expression\br delete-expression \end{bnf} \begin{bnf} \nontermdef{unary-operator} \textnormal{one of}\br \terminal{* \& + - ! \~} \end{bnf} \begin{bnf} \nontermdef{await-expression}\br \terminal{co_await} cast-expression \end{bnf} \begin{bnf} \nontermdef{noexcept-expression}\br \keyword{noexcept} \terminal{(} expression \terminal{)} \end{bnf} \begin{bnf} \nontermdef{new-expression}\br \opt{\terminal{::}} \keyword{new} \opt{new-placement} new-type-id \opt{new-initializer} \br \opt{\terminal{::}} \keyword{new} \opt{new-placement} \terminal{(} type-id \terminal{)} \opt{new-initializer} \end{bnf} \begin{bnf} \nontermdef{new-placement}\br \terminal{(} expression-list \terminal{)} \end{bnf} \begin{bnf} \nontermdef{new-type-id}\br type-specifier-seq \opt{new-declarator} \end{bnf} \begin{bnf} \nontermdef{new-declarator}\br ptr-operator \opt{new-declarator} \br noptr-new-declarator \end{bnf} \begin{bnf} \nontermdef{noptr-new-declarator}\br \terminal{[} \opt{expression} \terminal{]} \opt{attribute-specifier-seq}\br noptr-new-declarator \terminal{[} constant-expression \terminal{]} \opt{attribute-specifier-seq} \end{bnf} \begin{bnf} \nontermdef{new-initializer}\br \terminal{(} \opt{expression-list} \terminal{)}\br braced-init-list \end{bnf} \begin{bnf} \nontermdef{delete-expression}\br \opt{\terminal{::}} \keyword{delete} cast-expression\br \opt{\terminal{::}} \keyword{delete} \terminal{[} \terminal{]} cast-expression \end{bnf} \begin{bnf} \nontermdef{cast-expression}\br unary-expression\br \terminal{(} type-id \terminal{)} cast-expression \end{bnf} \begin{bnf} \nontermdef{pm-expression}\br cast-expression\br pm-expression \terminal{.*} cast-expression\br pm-expression \terminal{->*} cast-expression \end{bnf} \begin{bnf} \nontermdef{multiplicative-expression}\br pm-expression\br multiplicative-expression \terminal{*} pm-expression\br multiplicative-expression \terminal{/} pm-expression\br multiplicative-expression \terminal{\%} pm-expression \end{bnf} \begin{bnf} \nontermdef{additive-expression}\br multiplicative-expression\br additive-expression \terminal{+} multiplicative-expression\br additive-expression \terminal{-} multiplicative-expression \end{bnf} \begin{bnf} \nontermdef{shift-expression}\br additive-expression\br shift-expression \terminal{<<} additive-expression\br shift-expression \terminal{>>} additive-expression \end{bnf} \begin{bnf} \nontermdef{compare-expression}\br shift-expression\br compare-expression \terminal{<=>} shift-expression \end{bnf} \begin{bnf} \nontermdef{relational-expression}\br compare-expression\br relational-expression \terminal{<} compare-expression\br relational-expression \terminal{>} compare-expression\br relational-expression \terminal{<=} compare-expression\br relational-expression \terminal{>=} compare-expression \end{bnf} \begin{bnf} \nontermdef{equality-expression}\br relational-expression\br equality-expression \terminal{==} relational-expression\br equality-expression \terminal{!=} relational-expression \end{bnf} \begin{bnf} \nontermdef{and-expression}\br equality-expression\br and-expression \terminal{\&} equality-expression \end{bnf} \begin{bnf} \nontermdef{exclusive-or-expression}\br and-expression\br exclusive-or-expression \terminal{\caret} and-expression \end{bnf} \begin{bnf} \nontermdef{inclusive-or-expression}\br exclusive-or-expression\br inclusive-or-expression \terminal{|} exclusive-or-expression \end{bnf} \begin{bnf} \nontermdef{logical-and-expression}\br inclusive-or-expression\br logical-and-expression \terminal{\&\&} inclusive-or-expression \end{bnf} \begin{bnf} \nontermdef{logical-or-expression}\br logical-and-expression\br logical-or-expression \terminal{||} logical-and-expression \end{bnf} \begin{bnf} \nontermdef{conditional-expression}\br logical-or-expression\br logical-or-expression \terminal{?} expression \terminal{:} assignment-expression \end{bnf} \begin{bnf} \nontermdef{yield-expression}\br \terminal{co_yield} assignment-expression\br \terminal{co_yield} braced-init-list \end{bnf} \begin{bnf} \nontermdef{throw-expression}\br \keyword{throw} \opt{assignment-expression} \end{bnf} \begin{bnf} \nontermdef{assignment-expression}\br conditional-expression\br yield-expression\br throw-expression\br logical-or-expression assignment-operator initializer-clause \end{bnf} \begin{bnf} \nontermdef{assignment-operator} \textnormal{one of}\br \terminal{= *= /= \%= += -= >>= <<= \&= \caret= |=} \end{bnf} \begin{bnf} \nontermdef{expression}\br assignment-expression\br expression \terminal{,} assignment-expression \end{bnf} \begin{bnf} \nontermdef{constant-expression}\br conditional-expression \end{bnf} \gramSec[gram.stmt]{Statements} \begin{bnf} \nontermdef{statement}\br labeled-statement\br \opt{attribute-specifier-seq} expression-statement\br \opt{attribute-specifier-seq} compound-statement\br \opt{attribute-specifier-seq} selection-statement\br \opt{attribute-specifier-seq} iteration-statement\br \opt{attribute-specifier-seq} jump-statement\br declaration-statement\br \opt{attribute-specifier-seq} try-block \end{bnf} \begin{bnf} \nontermdef{init-statement}\br expression-statement\br simple-declaration \end{bnf} \begin{bnf} \nontermdef{condition}\br expression\br \opt{attribute-specifier-seq} decl-specifier-seq declarator brace-or-equal-initializer \end{bnf} \begin{bnf} \nontermdef{labeled-statement}\br \opt{attribute-specifier-seq} identifier \terminal{:} statement\br \opt{attribute-specifier-seq} \keyword{case} constant-expression \terminal{:} statement\br \opt{attribute-specifier-seq} \keyword{default} \terminal{:} statement \end{bnf} \begin{bnf} \nontermdef{expression-statement}\br \opt{expression} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{compound-statement}\br \terminal{\{} \opt{statement-seq} \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{statement-seq}\br statement\br statement-seq statement \end{bnf} \begin{bnf} \nontermdef{selection-statement}\br \keyword{if} \opt{\keyword{constexpr}} \terminal{(} \opt{init-statement} condition \terminal{)} statement\br \keyword{if} \opt{\keyword{constexpr}} \terminal{(} \opt{init-statement} condition \terminal{)} statement \keyword{else} statement\br \keyword{switch} \terminal{(} \opt{init-statement} condition \terminal{)} statement \end{bnf} \begin{bnf} \nontermdef{iteration-statement}\br \keyword{while} \terminal{(} condition \terminal{)} statement\br \keyword{do} statement \keyword{while} \terminal{(} expression \terminal{)} \terminal{;}\br \keyword{for} \terminal{(} init-statement \opt{condition} \terminal{;} \opt{expression} \terminal{)} statement\br \keyword{for} \terminal{(} \opt{init-statement} for-range-declaration \terminal{:} for-range-initializer \terminal{)} statement \end{bnf} \begin{bnf} \nontermdef{for-range-declaration}\br \opt{attribute-specifier-seq} decl-specifier-seq declarator\br \opt{attribute-specifier-seq} decl-specifier-seq \opt{ref-qualifier} \terminal{[} identifier-list \terminal{]} \end{bnf} \begin{bnf} \nontermdef{for-range-initializer}\br expr-or-braced-init-list \end{bnf} \begin{bnf} \nontermdef{jump-statement}\br \keyword{break} \terminal{;}\br \keyword{continue} \terminal{;}\br \keyword{return} \opt{expr-or-braced-init-list} \terminal{;}\br coroutine-return-statement\br \keyword{goto} identifier \terminal{;} \end{bnf} \begin{bnf} \nontermdef{coroutine-return-statement}\br \terminal{co_return} \opt{expr-or-braced-init-list} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{declaration-statement}\br block-declaration \end{bnf} \gramSec[gram.dcl]{Declarations} \begin{bnf} \nontermdef{declaration-seq}\br declaration\br declaration-seq declaration \end{bnf} \begin{bnf} \nontermdef{declaration}\br block-declaration\br nodeclspec-function-declaration\br function-definition\br template-declaration\br deduction-guide\br explicit-instantiation\br explicit-specialization\br export-declaration\br linkage-specification\br namespace-definition\br empty-declaration\br attribute-declaration\br module-import-declaration \end{bnf} \begin{bnf} \nontermdef{block-declaration}\br simple-declaration\br asm-declaration\br namespace-alias-definition\br using-declaration\br using-enum-declaration\br using-directive\br static_assert-declaration\br alias-declaration\br opaque-enum-declaration \end{bnf} \begin{bnf} \nontermdef{nodeclspec-function-declaration}\br \opt{attribute-specifier-seq} declarator \terminal{;} \end{bnf} \begin{bnf} \nontermdef{alias-declaration}\br \keyword{using} identifier \opt{attribute-specifier-seq} \terminal{=} defining-type-id \terminal{;} \end{bnf} \begin{bnf} \nontermdef{simple-declaration}\br decl-specifier-seq \opt{init-declarator-list} \terminal{;}\br attribute-specifier-seq decl-specifier-seq init-declarator-list \terminal{;}\br \opt{attribute-specifier-seq} decl-specifier-seq \opt{ref-qualifier} \terminal{[} identifier-list \terminal{]} initializer \terminal{;} \end{bnf} \begin{bnf} \nontermdef{static_assert-declaration}\br \keyword{static_assert} \terminal{(} constant-expression \terminal{)} \terminal{;}\br \keyword{static_assert} \terminal{(} constant-expression \terminal{,} string-literal \terminal{)} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{empty-declaration}\br \terminal{;} \end{bnf} \begin{bnf} \nontermdef{attribute-declaration}\br attribute-specifier-seq \terminal{;} \end{bnf} \begin{bnf} \nontermdef{decl-specifier}\br storage-class-specifier\br defining-type-specifier\br function-specifier\br \keyword{friend}\br \keyword{typedef}\br \keyword{constexpr}\br \keyword{consteval}\br \keyword{constinit}\br \keyword{inline} \end{bnf} \begin{bnf} \nontermdef{decl-specifier-seq}\br decl-specifier \opt{attribute-specifier-seq}\br decl-specifier decl-specifier-seq \end{bnf} \begin{bnf} \nontermdef{storage-class-specifier}\br \keyword{static}\br \keyword{thread_local}\br \keyword{extern}\br \keyword{mutable} \end{bnf} \begin{bnf} \nontermdef{function-specifier}\br \keyword{virtual}\br explicit-specifier \end{bnf} \begin{bnf} \nontermdef{explicit-specifier}\br \keyword{explicit} \terminal{(} constant-expression \terminal{)}\br \keyword{explicit} \end{bnf} \begin{bnf} \nontermdef{typedef-name}\br identifier\br simple-template-id \end{bnf} \begin{bnf} \nontermdef{type-specifier}\br simple-type-specifier\br elaborated-type-specifier\br typename-specifier\br cv-qualifier \end{bnf} \begin{bnf} \nontermdef{type-specifier-seq}\br type-specifier \opt{attribute-specifier-seq}\br type-specifier type-specifier-seq \end{bnf} \begin{bnf} \nontermdef{defining-type-specifier}\br type-specifier\br class-specifier\br enum-specifier \end{bnf} \begin{bnf} \nontermdef{defining-type-specifier-seq}\br defining-type-specifier \opt{attribute-specifier-seq}\br defining-type-specifier defining-type-specifier-seq \end{bnf} \begin{bnf} \nontermdef{simple-type-specifier}\br \opt{nested-name-specifier} type-name\br nested-name-specifier \keyword{template} simple-template-id\br decltype-specifier\br placeholder-type-specifier\br \opt{nested-name-specifier} template-name\br \keyword{char}\br \keyword{char8_t}\br \keyword{char16_t}\br \keyword{char32_t}\br \keyword{wchar_t}\br \keyword{bool}\br \keyword{short}\br \keyword{int}\br \keyword{long}\br \keyword{signed}\br \keyword{unsigned}\br \keyword{float}\br \keyword{double}\br \keyword{void} \end{bnf} \begin{bnf} \nontermdef{type-name}\br class-name\br enum-name\br typedef-name \end{bnf} \begin{bnf} \nontermdef{elaborated-type-specifier}\br class-key \opt{attribute-specifier-seq} \opt{nested-name-specifier} identifier\br class-key simple-template-id\br class-key nested-name-specifier \opt{\keyword{template}} simple-template-id\br elaborated-enum-specifier \end{bnf} \begin{bnf} \nontermdef{elaborated-enum-specifier}\br \keyword{enum} \opt{nested-name-specifier} identifier \end{bnf} \begin{bnf} \nontermdef{decltype-specifier}\br \keyword{decltype} \terminal{(} expression \terminal{)} \end{bnf} \begin{bnf} \nontermdef{placeholder-type-specifier}\br \opt{type-constraint} \keyword{auto}\br \opt{type-constraint} \keyword{decltype} \terminal{(} \keyword{auto} \terminal{)} \end{bnf} \begin{bnf} \nontermdef{init-declarator-list}\br init-declarator\br init-declarator-list \terminal{,} init-declarator \end{bnf} \begin{bnf} \nontermdef{init-declarator}\br declarator \opt{initializer}\br declarator requires-clause \end{bnf} \begin{bnf} \nontermdef{declarator}\br ptr-declarator\br noptr-declarator parameters-and-qualifiers trailing-return-type \end{bnf} \begin{bnf} \nontermdef{ptr-declarator}\br noptr-declarator\br ptr-operator ptr-declarator \end{bnf} \begin{bnf} \nontermdef{noptr-declarator}\br declarator-id \opt{attribute-specifier-seq}\br noptr-declarator parameters-and-qualifiers\br noptr-declarator \terminal{[} \opt{constant-expression} \terminal{]} \opt{attribute-specifier-seq}\br \terminal{(} ptr-declarator \terminal{)} \end{bnf} \begin{bnf} \nontermdef{parameters-and-qualifiers}\br \terminal{(} parameter-declaration-clause \terminal{)} \opt{cv-qualifier-seq}\br \bnfindent\opt{ref-qualifier} \opt{noexcept-specifier} \opt{attribute-specifier-seq} \end{bnf} \begin{bnf} \nontermdef{trailing-return-type}\br \terminal{->} type-id \end{bnf} \begin{bnf} \nontermdef{ptr-operator}\br \terminal{*} \opt{attribute-specifier-seq} \opt{cv-qualifier-seq}\br \terminal{\&} \opt{attribute-specifier-seq}\br \terminal{\&\&} \opt{attribute-specifier-seq}\br nested-name-specifier \terminal{*} \opt{attribute-specifier-seq} \opt{cv-qualifier-seq} \end{bnf} \begin{bnf} \nontermdef{cv-qualifier-seq}\br cv-qualifier \opt{cv-qualifier-seq} \end{bnf} \begin{bnf} \nontermdef{cv-qualifier}\br \keyword{const}\br \keyword{volatile} \end{bnf} \begin{bnf} \nontermdef{ref-qualifier}\br \terminal{\&}\br \terminal{\&\&} \end{bnf} \begin{bnf} \nontermdef{declarator-id}\br \opt{\terminal{...}} id-expression \end{bnf} \begin{bnf} \nontermdef{type-id}\br type-specifier-seq \opt{abstract-declarator} \end{bnf} \begin{bnf} \nontermdef{defining-type-id}\br defining-type-specifier-seq \opt{abstract-declarator} \end{bnf} \begin{bnf} \nontermdef{abstract-declarator}\br ptr-abstract-declarator\br \opt{noptr-abstract-declarator} parameters-and-qualifiers trailing-return-type\br abstract-pack-declarator \end{bnf} \begin{bnf} \nontermdef{ptr-abstract-declarator}\br noptr-abstract-declarator\br ptr-operator \opt{ptr-abstract-declarator} \end{bnf} \begin{bnf} \nontermdef{noptr-abstract-declarator}\br \opt{noptr-abstract-declarator} parameters-and-qualifiers\br \opt{noptr-abstract-declarator} \terminal{[} \opt{constant-expression} \terminal{]} \opt{attribute-specifier-seq}\br \terminal{(} ptr-abstract-declarator \terminal{)} \end{bnf} \begin{bnf} \nontermdef{abstract-pack-declarator}\br noptr-abstract-pack-declarator\br ptr-operator abstract-pack-declarator \end{bnf} \begin{bnf} \nontermdef{noptr-abstract-pack-declarator}\br noptr-abstract-pack-declarator parameters-and-qualifiers\br noptr-abstract-pack-declarator \terminal{[} \opt{constant-expression} \terminal{]} \opt{attribute-specifier-seq}\br \terminal{...} \end{bnf} \begin{bnf} \nontermdef{parameter-declaration-clause}\br \opt{parameter-declaration-list} \opt{\terminal{...}}\br parameter-declaration-list \terminal{,} \terminal{...} \end{bnf} \begin{bnf} \nontermdef{parameter-declaration-list}\br parameter-declaration\br parameter-declaration-list \terminal{,} parameter-declaration \end{bnf} \begin{bnf} \nontermdef{parameter-declaration}\br \opt{attribute-specifier-seq} decl-specifier-seq declarator\br \opt{attribute-specifier-seq} decl-specifier-seq declarator \terminal{=} initializer-clause\br \opt{attribute-specifier-seq} decl-specifier-seq \opt{abstract-declarator}\br \opt{attribute-specifier-seq} decl-specifier-seq \opt{abstract-declarator} \terminal{=} initializer-clause \end{bnf} \begin{bnf} \nontermdef{initializer}\br brace-or-equal-initializer\br \terminal{(} expression-list \terminal{)} \end{bnf} \begin{bnf} \nontermdef{brace-or-equal-initializer}\br \terminal{=} initializer-clause\br braced-init-list \end{bnf} \begin{bnf} \nontermdef{initializer-clause}\br assignment-expression\br braced-init-list \end{bnf} \begin{bnf} \nontermdef{braced-init-list}\br \terminal{\{} initializer-list \opt{\terminal{,}} \terminal{\}}\br \terminal{\{} designated-initializer-list \opt{\terminal{,}} \terminal{\}}\br \terminal{\{} \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{initializer-list}\br initializer-clause \opt{\terminal{...}}\br initializer-list \terminal{,} initializer-clause \opt{\terminal{...}} \end{bnf} \begin{bnf} \nontermdef{designated-initializer-list}\br designated-initializer-clause\br designated-initializer-list \terminal{,} designated-initializer-clause \end{bnf} \begin{bnf} \nontermdef{designated-initializer-clause}\br designator brace-or-equal-initializer \end{bnf} \begin{bnf} \nontermdef{designator}\br \terminal{.} identifier \end{bnf} \begin{bnf} \nontermdef{expr-or-braced-init-list}\br expression\br braced-init-list \end{bnf} \begin{bnf} \nontermdef{function-definition}\br \opt{attribute-specifier-seq} \opt{decl-specifier-seq} declarator \opt{virt-specifier-seq} function-body\br \opt{attribute-specifier-seq} \opt{decl-specifier-seq} declarator requires-clause function-body \end{bnf} \begin{bnf} \nontermdef{function-body}\br \opt{ctor-initializer} compound-statement\br function-try-block\br \terminal{=} \keyword{default} \terminal{;}\br \terminal{=} \keyword{delete} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{enum-name}\br identifier \end{bnf} \begin{bnf} \nontermdef{enum-specifier}\br enum-head \terminal{\{} \opt{enumerator-list} \terminal{\}}\br enum-head \terminal{\{} enumerator-list \terminal{,} \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{enum-head}\br enum-key \opt{attribute-specifier-seq} \opt{enum-head-name} \opt{enum-base} \end{bnf} \begin{bnf} \nontermdef{enum-head-name}\br \opt{nested-name-specifier} identifier \end{bnf} \begin{bnf} \nontermdef{opaque-enum-declaration}\br enum-key \opt{attribute-specifier-seq} enum-head-name \opt{enum-base} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{enum-key}\br \keyword{enum}\br \keyword{enum} \keyword{class}\br \keyword{enum} \keyword{struct} \end{bnf} \begin{bnf} \nontermdef{enum-base}\br \terminal{:} type-specifier-seq \end{bnf} \begin{bnf} \nontermdef{enumerator-list}\br enumerator-definition\br enumerator-list \terminal{,} enumerator-definition \end{bnf} \begin{bnf} \nontermdef{enumerator-definition}\br enumerator\br enumerator \terminal{=} constant-expression \end{bnf} \begin{bnf} \nontermdef{enumerator}\br identifier \opt{attribute-specifier-seq} \end{bnf} \begin{bnf} \nontermdef{using-enum-declaration}\br \terminal{using} elaborated-enum-specifier \terminal{;} \end{bnf} \begin{bnf} \nontermdef{namespace-name}\br identifier\br namespace-alias \end{bnf} \begin{bnf} \nontermdef{namespace-definition}\br named-namespace-definition\br unnamed-namespace-definition\br nested-namespace-definition \end{bnf} \begin{bnf} \nontermdef{named-namespace-definition}\br \opt{\keyword{inline}} \keyword{namespace} \opt{attribute-specifier-seq} identifier \terminal{\{} namespace-body \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{unnamed-namespace-definition}\br \opt{\keyword{inline}} \keyword{namespace} \opt{attribute-specifier-seq} \terminal{\{} namespace-body \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{nested-namespace-definition}\br \keyword{namespace} enclosing-namespace-specifier \terminal{::} \opt{\keyword{inline}} identifier \terminal{\{} namespace-body \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{enclosing-namespace-specifier}\br identifier\br enclosing-namespace-specifier \terminal{::} \opt{\keyword{inline}} identifier \end{bnf} \begin{bnf} \nontermdef{namespace-body}\br \opt{declaration-seq} \end{bnf} \begin{bnf} \nontermdef{namespace-alias}\br identifier \end{bnf} \begin{bnf} \nontermdef{namespace-alias-definition}\br \keyword{namespace} identifier \terminal{=} qualified-namespace-specifier \terminal{;} \end{bnf} \begin{bnf} \nontermdef{qualified-namespace-specifier}\br \opt{nested-name-specifier} namespace-name \end{bnf} \begin{bnf} \nontermdef{using-directive}\br \opt{attribute-specifier-seq} \keyword{using} \keyword{namespace} \opt{nested-name-specifier} namespace-name \terminal{;} \end{bnf} \begin{bnf} \nontermdef{using-declaration}\br \keyword{using} using-declarator-list \terminal{;} \end{bnf} \begin{bnf} \nontermdef{using-declarator-list}\br using-declarator \opt{\terminal{...}}\br using-declarator-list \terminal{,} using-declarator \opt{\terminal{...}} \end{bnf} \begin{bnf} \nontermdef{using-declarator}\br \opt{\keyword{typename}} nested-name-specifier unqualified-id \end{bnf} \begin{bnf} \nontermdef{asm-declaration}\br \opt{attribute-specifier-seq} \keyword{asm} \terminal{(} string-literal \terminal{)} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{linkage-specification}\br \keyword{extern} string-literal \terminal{\{} \opt{declaration-seq} \terminal{\}}\br \keyword{extern} string-literal declaration \end{bnf} \begin{bnf} \nontermdef{attribute-specifier-seq}\br \opt{attribute-specifier-seq} attribute-specifier \end{bnf} \begin{bnf} \nontermdef{attribute-specifier}\br \terminal{[} \terminal{[} \opt{attribute-using-prefix} attribute-list \terminal{]} \terminal{]}\br alignment-specifier \end{bnf} \begin{bnf} \nontermdef{alignment-specifier}\br \keyword{alignas} \terminal{(} type-id \opt{\terminal{...}} \terminal{)}\br \keyword{alignas} \terminal{(} constant-expression \opt{\terminal{...}} \terminal{)} \end{bnf} \begin{bnf} \nontermdef{attribute-using-prefix}\br \keyword{using} attribute-namespace \terminal{:} \end{bnf} \begin{bnf} \nontermdef{attribute-list}\br \opt{attribute}\br attribute-list \terminal{,} \opt{attribute}\br attribute \terminal{...}\br attribute-list \terminal{,} attribute \terminal{...} \end{bnf} \begin{bnf} \nontermdef{attribute}\br attribute-token \opt{attribute-argument-clause} \end{bnf} \begin{bnf} \nontermdef{attribute-token}\br identifier\br attribute-scoped-token \end{bnf} \begin{bnf} \nontermdef{attribute-scoped-token}\br attribute-namespace \terminal{::} identifier \end{bnf} \begin{bnf} \nontermdef{attribute-namespace}\br identifier \end{bnf} \begin{bnf} \nontermdef{attribute-argument-clause}\br \terminal{(} \opt{balanced-token-seq} \terminal{)} \end{bnf} \begin{bnf} \nontermdef{balanced-token-seq}\br balanced-token\br balanced-token-seq balanced-token \end{bnf} \begin{bnf} \nontermdef{balanced-token}\br \terminal{(} \opt{balanced-token-seq} \terminal{)}\br \terminal{[} \opt{balanced-token-seq} \terminal{]}\br \terminal{\{} \opt{balanced-token-seq} \terminal{\}}\br \textnormal{any \grammarterm{token} other than a parenthesis, a bracket, or a brace} \end{bnf} \gramSec[gram.module]{Modules} \begin{bnf} \nontermdef{module-declaration}\br \opt{export-keyword} module-keyword module-name \opt{module-partition} \opt{attribute-specifier-seq} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{module-name}\br \opt{module-name-qualifier} identifier \end{bnf} \begin{bnf} \nontermdef{module-partition}\br \terminal{:} \opt{module-name-qualifier} identifier \end{bnf} \begin{bnf} \nontermdef{module-name-qualifier}\br identifier \terminal{.}\br module-name-qualifier identifier \terminal{.} \end{bnf} \begin{bnf} \nontermdef{export-declaration}\br \keyword{export} declaration\br \keyword{export} \terminal{\{} \opt{declaration-seq} \terminal{\}}\br export-keyword module-import-declaration \end{bnf} \begin{bnf} \nontermdef{module-import-declaration}\br import-keyword module-name \opt{attribute-specifier-seq} \terminal{;}\br import-keyword module-partition \opt{attribute-specifier-seq} \terminal{;}\br import-keyword header-name \opt{attribute-specifier-seq} \terminal{;} \end{bnf} \begin{bnf} \nontermdef{global-module-fragment}\br module-keyword \terminal{;} \opt{declaration-seq} \end{bnf} \begin{bnf} \nontermdef{private-module-fragment}\br module-keyword \terminal{:} \keyword{private} \terminal{;} \opt{declaration-seq} \end{bnf} \gramSec[gram.class]{Classes} \begin{bnf} \nontermdef{class-name}\br identifier\br simple-template-id \end{bnf} \begin{bnf} \nontermdef{class-specifier}\br class-head \terminal{\{} \opt{member-specification} \terminal{\}} \end{bnf} \begin{bnf} \nontermdef{class-head}\br class-key \opt{attribute-specifier-seq} class-head-name \opt{class-virt-specifier} \opt{base-clause}\br class-key \opt{attribute-specifier-seq} \opt{base-clause} \end{bnf} \begin{bnf} \nontermdef{class-head-name}\br \opt{nested-name-specifier} class-name \end{bnf} \begin{bnf} \nontermdef{class-virt-specifier}\br \keyword{final} \end{bnf} \begin{bnf} \nontermdef{class-key}\br \keyword{class}\br \keyword{struct}\br \keyword{union} \end{bnf} \begin{bnf} \nontermdef{member-specification}\br member-declaration \opt{member-specification}\br access-specifier \terminal{:} \opt{member-specification} \end{bnf} \begin{bnf} \nontermdef{member-declaration}\br \opt{attribute-specifier-seq} \opt{decl-specifier-seq} \opt{member-declarator-list} \terminal{;}\br function-definition\br using-declaration\br using-enum-declaration\br static_assert-declaration\br template-declaration\br explicit-specialization\br deduction-guide\br alias-declaration\br opaque-enum-declaration\br empty-declaration \end{bnf} \begin{bnf} \nontermdef{member-declarator-list}\br member-declarator\br member-declarator-list \terminal{,} member-declarator \end{bnf} \begin{bnf} \nontermdef{member-declarator}\br declarator \opt{virt-specifier-seq} \opt{pure-specifier}\br declarator requires-clause\br declarator \opt{brace-or-equal-initializer}\br \opt{identifier} \opt{attribute-specifier-seq} \terminal{:} constant-expression \opt{brace-or-equal-initializer} \end{bnf} \begin{bnf} \nontermdef{virt-specifier-seq}\br virt-specifier\br virt-specifier-seq virt-specifier \end{bnf} \begin{bnf} \nontermdef{virt-specifier}\br \keyword{override}\br \keyword{final} \end{bnf} \begin{bnf} \nontermdef{pure-specifier}\br \terminal{=} \terminal{0} \end{bnf} \begin{bnf} \nontermdef{conversion-function-id}\br \keyword{operator} conversion-type-id \end{bnf} \begin{bnf} \nontermdef{conversion-type-id}\br type-specifier-seq \opt{conversion-declarator} \end{bnf} \begin{bnf} \nontermdef{conversion-declarator}\br ptr-operator \opt{conversion-declarator} \end{bnf} \begin{bnf} \nontermdef{base-clause}\br \terminal{:} base-specifier-list \end{bnf} \begin{bnf} \nontermdef{base-specifier-list}\br base-specifier \opt{\terminal{...}}\br base-specifier-list \terminal{,} base-specifier \opt{\terminal{...}} \end{bnf} \begin{bnf} \nontermdef{base-specifier}\br \opt{attribute-specifier-seq} class-or-decltype\br \opt{attribute-specifier-seq} \keyword{virtual} \opt{access-specifier} class-or-decltype\br \opt{attribute-specifier-seq} access-specifier \opt{\keyword{virtual}} class-or-decltype \end{bnf} \begin{bnf} \nontermdef{class-or-decltype}\br \opt{nested-name-specifier} type-name\br nested-name-specifier \keyword{template} simple-template-id\br decltype-specifier \end{bnf} \begin{bnf} \nontermdef{access-specifier}\br \keyword{private}\br \keyword{protected}\br \keyword{public} \end{bnf} \begin{bnf} \nontermdef{ctor-initializer}\br \terminal{:} mem-initializer-list \end{bnf} \begin{bnf} \nontermdef{mem-initializer-list}\br mem-initializer \opt{\terminal{...}}\br mem-initializer-list \terminal{,} mem-initializer \opt{\terminal{...}} \end{bnf} \begin{bnf} \nontermdef{mem-initializer}\br mem-initializer-id \terminal{(} \opt{expression-list} \terminal{)}\br mem-initializer-id braced-init-list \end{bnf} \begin{bnf} \nontermdef{mem-initializer-id}\br class-or-decltype\br identifier \end{bnf} \gramSec[gram.over]{Overloading} \begin{bnf} \nontermdef{operator-function-id}\br \keyword{operator} operator \end{bnf} \begin{bnf} %% Ed. note: character protrusion would misalign various operators. \microtypesetup{protrusion=false}\obeyspaces \nontermdef{operator} \textnormal{one of}\br \terminal{new delete new[] delete[] co_await (\rlap{\,)} [\rlap{\,]} -> ->*}\br \terminal{\~ ! + - * / \% \caret{} \&}\br \terminal{| = += -= *= /= \%= \caret{}= \&=}\br \terminal{|= == != < > <= >= <=> \&\&}\br \terminal{|| << >> <<= >>= ++ -- ,}\br \end{bnf} \begin{bnf} \nontermdef{literal-operator-id}\br \keyword{operator} string-literal identifier\br \keyword{operator} user-defined-string-literal \end{bnf} \gramSec[gram.temp]{Templates} \begin{bnf} \nontermdef{template-declaration}\br template-head declaration\br template-head concept-definition \end{bnf} \begin{bnf} \nontermdef{template-head}\br \keyword{template} \terminal{<} template-parameter-list \terminal{>} \opt{requires-clause} \end{bnf} \begin{bnf} \nontermdef{template-parameter-list}\br template-parameter\br template-parameter-list \terminal{,} template-parameter \end{bnf} \begin{bnf} \nontermdef{requires-clause}\br \keyword{requires} constraint-logical-or-expression \end{bnf} \begin{bnf} \nontermdef{constraint-logical-or-expression}\br constraint-logical-and-expression\br constraint-logical-or-expression \terminal{||} constraint-logical-and-expression \end{bnf} \begin{bnf} \nontermdef{constraint-logical-and-expression}\br primary-expression\br constraint-logical-and-expression \terminal{\&\&} primary-expression \end{bnf} \begin{bnf} \nontermdef{template-parameter}\br type-parameter\br parameter-declaration \end{bnf} \begin{bnf} \nontermdef{type-parameter}\br type-parameter-key \opt{\terminal{...}} \opt{identifier}\br type-parameter-key \opt{identifier} \terminal{=} type-id\br type-constraint \opt{\terminal{...}} \opt{identifier}\br type-constraint \opt{identifier} \terminal{=} type-id\br template-head type-parameter-key \opt{\terminal{...}} \opt{identifier}\br template-head type-parameter-key \opt{identifier} \terminal{=} id-expression \end{bnf} \begin{bnf} \nontermdef{type-parameter-key}\br \keyword{class}\br \keyword{typename} \end{bnf} \begin{bnf} \nontermdef{type-constraint}\br \opt{nested-name-specifier} concept-name\br \opt{nested-name-specifier} concept-name \terminal{<} \opt{template-argument-list} \terminal{>} \end{bnf} \begin{bnf} \nontermdef{simple-template-id}\br template-name \terminal{<} \opt{template-argument-list} \terminal{>} \end{bnf} \begin{bnf} \nontermdef{template-id}\br simple-template-id\br operator-function-id \terminal{<} \opt{template-argument-list} \terminal{>}\br literal-operator-id \terminal{<} \opt{template-argument-list} \terminal{>} \end{bnf} \begin{bnf} \nontermdef{template-name}\br identifier \end{bnf} \begin{bnf} \nontermdef{template-argument-list}\br template-argument \opt{\terminal{...}}\br template-argument-list \terminal{,} template-argument \opt{\terminal{...}} \end{bnf} \begin{bnf} \nontermdef{template-argument}\br constant-expression\br type-id\br id-expression \end{bnf} \begin{bnf} \nontermdef{constraint-expression}\br logical-or-expression \end{bnf} \begin{bnf} \nontermdef{deduction-guide}\br \opt{explicit-specifier} template-name \terminal{(} parameter-declaration-clause \terminal{)} \terminal{->} simple-template-id \terminal{;} \end{bnf} \begin{bnf} \nontermdef{concept-definition}\br \keyword{concept} concept-name \terminal{=} constraint-expression \terminal{;} \end{bnf} \begin{bnf} \nontermdef{concept-name}\br identifier \end{bnf} \begin{bnf} \nontermdef{typename-specifier}\br \keyword{typename} nested-name-specifier identifier\br \keyword{typename} nested-name-specifier \terminal{\opt{template}} simple-template-id \end{bnf} \begin{bnf} \nontermdef{explicit-instantiation}\br \opt{\keyword{extern}} \keyword{template} declaration \end{bnf} \begin{bnf} \nontermdef{explicit-specialization}\br \keyword{template} \terminal{<} \terminal{>} declaration \end{bnf} \gramSec[gram.except]{Exception handling} \begin{bnf} \nontermdef{try-block}\br \terminal{try} compound-statement handler-seq \end{bnf} \begin{bnf} \nontermdef{function-try-block}\br \terminal{try} \opt{ctor-initializer} compound-statement handler-seq \end{bnf} \begin{bnf} \nontermdef{handler-seq}\br handler \opt{handler-seq} \end{bnf} \begin{bnf} \nontermdef{handler}\br \terminal{catch} \terminal{(} exception-declaration \terminal{)} compound-statement \end{bnf} \begin{bnf} \nontermdef{exception-declaration}\br \opt{attribute-specifier-seq} type-specifier-seq declarator\br \opt{attribute-specifier-seq} type-specifier-seq \opt{abstract-declarator}\br \terminal{...} \end{bnf} \begin{bnf} \nontermdef{noexcept-specifier}\br \terminal{noexcept} \terminal{(} constant-expression \terminal{)}\br \terminal{noexcept}\br \end{bnf} \gramSec[gram.cpp]{Preprocessing directives} \begin{bnf} \nontermdef{preprocessing-file}\br \opt{group}\br module-file \end{bnf} \begin{bnf} \nontermdef{module-file}\br \opt{pp-global-module-fragment} pp-module \opt{group} \opt{pp-private-module-fragment} \end{bnf} \begin{bnf} \nontermdef{pp-global-module-fragment}\br \keyword{module} \terminal{;} new-line \opt{group} \end{bnf} \begin{bnf} \nontermdef{pp-private-module-fragment}\br \keyword{module} \terminal{:} \keyword{private} \terminal{;} new-line \opt{group} \end{bnf} \begin{bnf} \nontermdef{group}\br group-part\br group group-part \end{bnf} \begin{bnf} \nontermdef{group-part}\br control-line\br if-section\br text-line\br \terminal{\#} conditionally-supported-directive \end{bnf} \begin{bnf}\obeyspaces \nontermdef{control-line}\br \terminal{\# include} pp-tokens new-line\br pp-import\br \terminal{\# define } identifier replacement-list new-line\br \terminal{\# define } identifier lparen \opt{identifier-list} \terminal{)} replacement-list new-line\br \terminal{\# define } identifier lparen \terminal{... )} replacement-list new-line\br \terminal{\# define } identifier lparen identifier-list \terminal{, ... )} replacement-list new-line\br \terminal{\# undef } identifier new-line\br \terminal{\# line } pp-tokens new-line\br \terminal{\# error } \opt{pp-tokens} new-line\br \terminal{\# pragma } \opt{pp-tokens} new-line\br \terminal{\# }new-line \end{bnf} \begin{bnf} \nontermdef{if-section}\br if-group \opt{elif-groups} \opt{else-group} endif-line \end{bnf} \begin{bnf}\obeyspaces \nontermdef{if-group}\br \terminal{\# if } constant-expression new-line \opt{group}\br \terminal{\# ifdef } identifier new-line \opt{group}\br \terminal{\# ifndef } identifier new-line \opt{group} \end{bnf} \begin{bnf} \nontermdef{elif-groups}\br elif-group\br elif-groups elif-group \end{bnf} \begin{bnf}\obeyspaces \nontermdef{elif-group}\br \terminal{\# elif } constant-expression new-line \opt{group} \end{bnf} \begin{bnf}\obeyspaces \nontermdef{else-group}\br \terminal{\# else } new-line \opt{group} \end{bnf} \begin{bnf}\obeyspaces \nontermdef{endif-line}\br \terminal{\# endif } new-line \end{bnf} \begin{bnf} \nontermdef{text-line}\br \opt{pp-tokens} new-line \end{bnf} \begin{bnf} \nontermdef{conditionally-supported-directive}\br pp-tokens new-line \end{bnf} \begin{bnf} \nontermdef{lparen}\br \descr{a \terminal{(} character not immediately preceded by whitespace} \end{bnf} \begin{bnf} \nontermdef{identifier-list}\br identifier\br identifier-list \terminal{,} identifier \end{bnf} \begin{bnf} \nontermdef{replacement-list}\br \opt{pp-tokens} \end{bnf} \begin{bnf} \nontermdef{pp-tokens}\br preprocessing-token\br pp-tokens preprocessing-token \end{bnf} \begin{bnf} \nontermdef{new-line}\br \descr{the new-line character} \end{bnf} \begin{bnf} \nontermdef{defined-macro-expression}\br \terminal{defined} identifier\br \terminal{defined (} identifier \terminal{)} \end{bnf} \begin{bnf} \nontermdef{h-preprocessing-token}\br \textnormal{any \grammarterm{preprocessing-token} other than \terminal{>}} \end{bnf} \begin{bnf} \nontermdef{h-pp-tokens}\br h-preprocessing-token\br h-pp-tokens h-preprocessing-token \end{bnf} \begin{bnf} \nontermdef{header-name-tokens}\br string-literal\br \terminal{<} h-pp-tokens \terminal{>} \end{bnf} \begin{bnf} \nontermdef{has-include-expression}\br \terminal{\xname{has_include}} \terminal{(} header-name \terminal{)}\br \terminal{\xname{has_include}} \terminal{(} header-name-tokens \terminal{)} \end{bnf} \begin{bnf} \nontermdef{has-attribute-expression}\br \terminal{\xname{has_cpp_attribute} (} pp-tokens \terminal{)} \end{bnf} \begin{bnf} \nontermdef{pp-module}\br \opt{\keyword{export}} \keyword{module} \opt{pp-tokens} \terminal{;} new-line \end{bnf} \begin{bnf} \nontermdef{pp-import}\br \opt{\keyword{export}} \keyword{import} header-name \opt{pp-tokens} \terminal{;} new-line\br \opt{\keyword{export}} \keyword{import} header-name-tokens \opt{pp-tokens} \terminal{;} new-line\br \opt{\keyword{export}} \keyword{import} pp-tokens \terminal{;} new-line \end{bnf} \begin{bnf} \nontermdef{va-opt-replacement}\br \terminal{\mname{VA_OPT} (} \opt{pp-tokens} \terminal{)} \end{bnf}