Question

Is this allowed? :

class A; void foo() {     static A(); } 

I get signal 11 when I try to do it, but the following works fine:

class A; void foo() {     static A a; } 

Thank you.

Answer 1

Nope. There is no such thing as an ‘anonymous object’ in C++. There is such a thing as defining an object to type A that is immediately discarded; what you’ve written is an expression that returns an A object that’s never assigned to a variable, like the return code of printf usually is never assigned or used.

In that code, if it worked, you’d be declaring ‘no object’ to be allocated outside the heap. Since there’s no object to allocate, it’s meaningless.