https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87605
Bug ID: 87605
Summary: Ternary uses explicit copy constructor for
lvalue-to-rvalue conversion
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: namark at disroot dot org
Target Milestone: ---
The code below compiles and outputs "copy" to stdout when ran.
#include <cstdio>
struct A
{
A(){}
explicit A(const A&) {std::puts("copy");}
};
int main()
{
A a;
const A& b = true ? a : A();
return 0;
}
I'm using compiler version 8.1.0, but testing on godbolt.org all version
available there, except 4.1.2, do the same. 4.1.2 will do it as well if the
"const A& b = " is removed, leaving just the ternary by itself.
This felt wrong to me, but I'm not very well versed in the standard, so asked
on stack overflow
https://stackoverflow.com/questions/52720175/ternary-allowed-to-call-an-explicit-copy-constructor-implicitly
and the provided answer, confirming that this is a bug, seems correct.
