[dcl.spec.general]

The specifiers that can be used in a declaration are

decl-specifier:
storage-class-specifier
defining-type-specifier
function-specifier
friend
typedef
constexpr
consteval
constinit
inline

decl-specifier-seq:
decl-specifier attribute-specifier-seq

{o p t decl-specifier decl-specifier-seq}_{o p t decl-specifier decl-specifier-seq}

The optional attribute-specifier-seq in a decl-specifier-seq appertains to the type determined by the preceding decl-specifiers ([dcl.meaning]).

The attribute-specifier-seq affects the type only for the declaration it appears in, not other declarations involving the same type.

At most one of each of the decl-specifiers friend, typedef, or inline shall appear in a decl-specifier-seq.

At most one of the constexpr, consteval, and constinit keywords shall appear in a decl-specifier-seq.

If a type-name is encountered while parsing a decl-specifier-seq, it is interpreted as part of the decl-specifier-seq if and only if there is no previous defining-type-specifier other than a cv-qualifier in the decl-specifier-seq.

The sequence shall be self-consistent as described below.

[Example 1: typedef char* Pc; static Pc; / error: name missing

Here, the declaration static Pc is ill-formed because no name was specified for the static variable of type Pc.

To get a variable called Pc, a type-specifier (other than const or volatile) has to be present to indicate that the typedef-name Pc is the name being (re)declared, rather than being part of the decl-specifier sequence.

For another example, void f(const Pc); / void f(char* const) (not const char*) void g(const int Pc); / void g(const int)

— end example]

[Note 1:

Since signed, unsigned, long, and short by default imply int, a type-name appearing after one of those specifiers is treated as the name being (re)declared.

[Example 2: void h(unsigned Pc); / void h(unsigned int) void k(unsigned int Pc); / void k(unsigned int) — end example]

— end note]