🚀 go-pugleaf

On october 13, I asked:

|   is A a = 100; equivalent to A a (100); ?

If I well understand the different threads the answer is NO.

   A a = 100 is known as copy initialization and may or not require
   Copy constructor depending on compilers optimizations which can be
   different from a compiler to an other, but without taking in account
   copy constructor side effect.
   
Why C++ methods an functions could not be qualified as having "SideEffect".
This could enable compilers to make more and predictable optimizations.
Suppose this stupid code:

|   #include "A.h"
|   A a;
|   int x = a.val() + a.val();

If this code doesn't know A::val implementation, that is, A interface is
in A.h and A implementation in A.cc, A::val() will be called twice even
A::val() is a const method, because compiler can not see the implementation
of A::val() which can be:

	{return 1;} (no side effect)
or
	{return global_var++;}

The Side Effect property would be inherited by any function or method
which would have in its body a Side Effect function or method. global
or static variable affect, I/O would be Side Effect functions.

what about this ?

jlm

   

   
--
+----------------------------+------------------------------------+
|   Jean-Louis Moser         |    2001 SA                         |
|   tel: 33 (1)46.66.54.54   |    2, rue de la renaissance        |
|   Email: jlm@two-oo-one.fr |    F-92184 Antony Cedex            |
+----------------------------+------------------------------------+

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