21 Metaprogramming library [meta]

21.4 Reflection [meta.reflection]

21.4.2 Checking string literals [meta.string.literal]

consteval bool is_string_literal(const char* p);
consteval bool is_string_literal(const wchar_t* p);
consteval bool is_string_literal(const char8_t* p);
consteval bool is_string_literal(const char16_t* p);
consteval bool is_string_literal(const char32_t* p);

Returns:

(1.1)
If p points to an unspecified object ([expr.const]), false.
(1.2)
Otherwise, if p points to a subobject of a string literal object ([lex.string]), true.
(1.3)
Otherwise, false.