[dcl.type.simple]

A placeholder-type-specifier is a placeholder for a type to be deduced ([dcl.spec.auto]).

A type-specifier of the form typename

_{o p t}

nested-name-specifier

_{o p t}

template-name is a placeholder for a deduced class type ([dcl.type.class.deduct]).

The nested-name-specifier, if any, shall be non-dependent and the template-name shall name a deducible template.

A deducible template is either a class template or is an alias template whose defining-type-id is of the form

typename

_{o p t}

nested-name-specifier

_{o p t}

template

_{o p t}

simple-template-id

where the nested-name-specifier (if any) is non-dependent and the template-name of the simple-template-id names a deducible template.

[Note 1:

An injected-class-name is never interpreted as a template-name in contexts where class template argument deduction would be performed ([temp.local]).

— end note]

The other simple-type-specifiers specify either a previously-declared type, a type determined from an expression, or one of the fundamental types ([basic.fundamental]).

Table 14 summarizes the valid combinations of simple-type-specifiers and the types they specify.

Table 14: simple-type-specifiers and the types they specify [tab:dcl.type.simple]

🔗	Specifier(s)	Type
🔗	type-name	the type named
🔗	simple-template-id	the type as defined in [temp.names]
🔗	decltype-specifier	the type as defined in [dcl.type.decltype]
🔗	placeholder-type-specifier	the type as defined in [dcl.spec.auto]
🔗	template-name	the type as defined in [dcl.type.class.deduct]
🔗	char	“char”
🔗	unsigned char	“unsigned char”
🔗	signed char	“signed char”
🔗	char8_t	“char8_t”
🔗	char16_t	“char16_t”
🔗	char32_t	“char32_t”
🔗	bool	“bool”
🔗	unsigned	“unsigned int”
🔗	unsigned int	“unsigned int”
🔗	signed	“int”
🔗	signed int	“int”
🔗	int	“int”
🔗	unsigned short int	“unsigned short int”
🔗	unsigned short	“unsigned short int”
🔗	unsigned long int	“unsigned long int”
🔗	unsigned long	“unsigned long int”
🔗	unsigned long long int	“unsigned long long int”
🔗	unsigned long long	“unsigned long long int”
🔗	signed long int	“long int”
🔗	signed long	“long int”
🔗	signed long long int	“long long int”
🔗	signed long long	“long long int”
🔗	long long int	“long long int”
🔗	long long	“long long int”
🔗	long int	“long int”
🔗	long	“long int”
🔗	signed short int	“short int”
🔗	signed short	“short int”
🔗	short int	“short int”
🔗	short	“short int”
🔗	wchar_t	“wchar_t”
🔗	float	“float”
🔗	double	“double”
🔗	long double	“long double”
🔗	void	“void”

9 Declarations [dcl.dcl]

9.2 Specifiers [dcl.spec]

9.2.9 Type specifiers [dcl.type]

9.2.9.3 Simple type specifiers [dcl.type.simple]