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* [Bug c++/68051] New: copy constructor does not copy default initialized union member
@ 2015-10-22 15:24 akju at mailinator dot com
2015-10-22 16:59 ` [Bug c++/68051] " trippels at gcc dot gnu.org
2015-10-22 17:18 ` trippels at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: akju at mailinator dot com @ 2015-10-22 15:24 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68051
Bug ID: 68051
Summary: copy constructor does not copy default initialized
union member
Product: gcc
Version: 5.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: akju at mailinator dot com
Target Milestone: ---
The assertion at the end of the following code fails erroneously:
#include <string>
#include <cassert>
struct test
{
union {int v = 0;};
std::string dummy;
};
int main ()
{
test x;
x.v = 1;
test y = x;
assert (y.v == 1);
}
According to the assembly listing, it seems that the copy construction of y
uses the default member initializer of v instead of x.v. This behaviour does
not occur if the dummy member is removed causing the struct to be trivially
copyable.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-10-22 15:24 [Bug c++/68051] New: copy constructor does not copy default initialized union member akju at mailinator dot com
2015-10-22 16:59 ` [Bug c++/68051] " trippels at gcc dot gnu.org
2015-10-22 17:18 ` trippels at gcc dot gnu.org
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