[dcl.attr.noreturn] (original) (raw)

9 Declarations [dcl]

9.13 Attributes [dcl.attr]

9.13.10 Noreturn attribute [dcl.attr.noreturn]

The attribute-token noreturn specifies that a function does not return.

The attribute may be applied to a function or a lambda call operator.

The first declaration of a function shall specify the noreturn attribute if any declaration of that function specifies thenoreturn attribute.

If a function is declared with the noreturn attribute in one translation unit and the same function is declared without the noreturn attribute in another translation unit, the program is ill-formed, no diagnostic required.

If a function f is invoked where f was previously declared with the noreturnattribute and that invocation eventually returns, the behavior is runtime-undefined.

[Note 1:

The function can terminate by throwing an exception.

— _end note_]

Recommended practice: Implementations should issue a warning if a function marked [[noreturn]] might return.

The value of a has-attribute-expression for the noreturn attribute should be 0 unless the implementation can issue such warnings.

[Example 1: [[ noreturn ]] void f() { throw "error"; } [[ noreturn ]] void q(int i) { if (i > 0) throw "positive";} — _end example_]