[C/C++]C++标准

本文若如特别说明都引于ISO/IEC 14882:2011

7、声明(Declarations)

声明序列(declaration-seq):
    声明(declaration)
    声明序列(declaration-seq) 声明(declaration)
声明(declaration):
    block-declaration
    function-definition
    template-declaration
    explicit-instantiation
    explicit-specialization
    linkage-specification
    namespace-definition
    empty-declaration
    attribute-declaration
block-declaration:
    simple-declaration
    asm-definition
    namespace-alias-definition
    using-declaration
    using-directive
    static_assert-declaration
    alias-declaration
    opaque-enum-declaration
alias-declaration:
using identifier attribute-specifier-seqopt = type-id ;
simple-declaration:
    声明限定符序列[可选](decl-specifier-seqopt) init-declarator-listopt;
attribute-specifier-seq decl-specifier-seqopt init-declarator-list ;
static_assert-declaration:
static_assert ( constant-expression , string-literal ) ;
empty-declaration:
;
attribute-declaration:
attribute-specifier-seq ;

7.1、限定符(Specifiers)

decl-specifier:
    storage-class-specifier
    type-specifier
    function-specifier
    friend
    typedef
    constexpr
decl-specifier-seq:
    decl-specifier attribute-specifier-seqopt
    decl-specifier decl-specifier-seq

7.1.1、Storage class specifiers

storage-class-specifier:
    register
    static
    thread_local
    extern
    mutable

7.1.6、类型限定符(Type specifiers)

type-specifier:
trailing-type-specifier
class-specifier
enum-specifier
trailing-type-specifier:
simple-type-specifier
elaborated-type-specifier
typename-specifier
cv-qualifier
type-specifier-seq:
type-specifier attribute-specifier-seqopt
type-specifier type-specifier-seq
trailing-type-specifier-seq:
trailing-type-specifier attribute-specifier-seqopt
trailing-type-specifier trailing-type-specifier-seq

作为一般规则，最多一个类型说明符是完整的声明说明符声明的允许或SEQ

在类型说明符类型说明符序列SEQ或尾随。这个规则的唯一例外是以下：