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* [Bug c++/67768] New: Second and subsequent captured variable in variadic template unpaking are default constructed
@ 2015-09-29 15:02 dtyazskwindows7 at gmail dot com
2021-08-23 7:20 ` [Bug c++/67768] " pinskia at gcc dot gnu.org
0 siblings, 1 reply; 2+ messages in thread
From: dtyazskwindows7 at gmail dot com @ 2015-09-29 15:02 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67768
Bug ID: 67768
Summary: Second and subsequent captured variable in variadic
template unpaking are default constructed
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: dtyazskwindows7 at gmail dot com
Target Milestone: ---
When you compile and run the following code in gcc6.0
=================================
#include<iostream>
#include<utility>
#include<tuple>
template<std::size_t I,class T>T echo(T v)
{
return v;
}
template<std::size_t... Is>auto run(std::index_sequence<Is...>)
{
int x = 10;
return std::make_tuple(echo<Is>([y=x](){std::cout<<y<<std::endl;})...);
}
int main()
{
auto v = run(std::make_index_sequence<3>());
std::get<0>(v)();
std::get<1>(v)();
std::get<2>(v)();
}
========================================
output is as follows:
10
0
0
^ permalink raw reply [flat|nested] 2+ messages in thread
* [Bug c++/67768] Second and subsequent captured variable in variadic template unpaking are default constructed
2015-09-29 15:02 [Bug c++/67768] New: Second and subsequent captured variable in variadic template unpaking are default constructed dtyazskwindows7 at gmail dot com
@ 2021-08-23 7:20 ` pinskia at gcc dot gnu.org
0 siblings, 0 replies; 2+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-23 7:20 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67768
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |FIXED
Status|UNCONFIRMED |RESOLVED
Target Milestone|--- |8.0
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed in GCC 8. Here is a self contained testcase (no libstdc++ involved):
template<int I,class T>T echo(T v) { return v; }
template<typename ...T> struct run1;
template<> struct run1<>{};
template<typename T> struct run1<T>{run1(T a){a();}};
template<typename T, typename ...T1>
struct run1<T, T1...>
: run1<T1...>{run1(T a, T1... b) : run1<T1...>(b...) {a();}};
template<typename ...T>
void run11(T... a)
{
run1<T...>(a...);
}
template<int... Is>void run(void)
{
int x = 10;
run11(echo<Is>([y=x](){if (y!=10) __builtin_abort();})...);
}
int main()
{
run<0,1,2>();
}
-------- CUT ----------
^ permalink raw reply [flat|nested] 2+ messages in thread
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2015-09-29 15:02 [Bug c++/67768] New: Second and subsequent captured variable in variadic template unpaking are default constructed dtyazskwindows7 at gmail dot com
2021-08-23 7:20 ` [Bug c++/67768] " pinskia at gcc dot gnu.org
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