Topic: explicit call of constructor


Author: clamage@Eng.Sun.COM (Steve Clamage)
Date: 1995/11/18
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Paul Johnson <pjcj@transeda.demon.co.uk> writes:

>I am porting some code that was developed using g++ 2.7.0 on multiple
>platforms, and have come across several explicit calls of
>constructors.  My reading of the ARM and the latest draft to which I
>have access (28th April 95) suggests that this is not correct
>behaviour.

You are correct. It is invalid to attempt to call a constructor
directly (or to take the address of a constructor).

Evidently g++ allows calling a constructor as an extension.

You can usually get the effect of calling a constructor by
using placement-new. That is,
given:
 T* t = ...;
instead of:
 t->T(); // illegal
write:
 new (t) T(); // placement-new
--
Steve Clamage, stephen.clamage@eng.sun.com


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