[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 Andrew Pinski changed: What|Removed |Added CC||tomaszkam at gmail dot com --- Comment #11 from Andrew Pinski --- *** Bug 63999 has been marked as a duplicate of this bug. ***
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 --- Comment #10 from Howard Hinnant --- Thanks much Jason!
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 Jason Merrill changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED Target Milestone|--- |6.3 --- Comment #9 from Jason Merrill --- Fixed for 6.3.
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 --- Comment #8 from Jason Merrill --- Author: jason Date: Fri Nov 18 20:27:41 2016 New Revision: 242604 URL: https://gcc.gnu.org/viewcvs?rev=242604&root=gcc&view=rev Log: PR c++/67631 - list-init and explicit conversions * semantics.c (finish_compound_literal): Call digest_init_flags. * typeck2.c (digest_init_flags): Add complain parm. (store_init_value): Pass it. Added: branches/gcc-6-branch/gcc/testsuite/g++.dg/cpp0x/initlist-explicit1.C Modified: branches/gcc-6-branch/gcc/cp/ChangeLog branches/gcc-6-branch/gcc/cp/cp-tree.h branches/gcc-6-branch/gcc/cp/semantics.c branches/gcc-6-branch/gcc/cp/typeck2.c
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 --- Comment #7 from Jason Merrill --- Author: jason Date: Fri Nov 18 20:27:26 2016 New Revision: 242603 URL: https://gcc.gnu.org/viewcvs?rev=242603&root=gcc&view=rev Log: PR c++/67631 - list-init and explicit conversions * semantics.c (finish_compound_literal): Call digest_init_flags. * typeck2.c (digest_init_flags): Add complain parm. (store_init_value): Pass it. Added: trunk/gcc/testsuite/g++.dg/cpp0x/initlist-explicit1.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/cp-tree.h trunk/gcc/cp/semantics.c trunk/gcc/cp/typeck2.c
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 Jason Merrill changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jason at gcc dot gnu.org
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 --- Comment #6 from Howard Hinnant --- Dropping the `explicit` specifier for the operator is an "over my dead body", sorry. That would be horrible. The next best workaround is to "respell" the explicit int operator() as `as_int() const`. But then everyone has to remember library-specific API for the operation instead of Uniform Initialization Syntax.
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 --- Comment #5 from Markus Trippelsdorf --- A workaround is to drop the "explicit" specifier for the operator.
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631
--- Comment #4 from Howard Hinnant ---
This bug needs some attention because Howard Hinnant's date library is making
it common for people to hit this bug.
The date library:
https://github.com/HowardHinnant/date
This library is sufficiently popular and successful that it has been proposed
to the C++ committee for C++20.
Here is a short HelloWorld demonstrating the problem:
#include "date.h"
#include
int
main()
{
using namespace date;
using namespace std::chrono;
year_month_day ymd = floor(system_clock::now());
auto y = int{ymd.year()};
std::cout << y << '\n';
}
You can try this out without installing the library at:
http://melpon.org/wandbox/permlink/PodYB3AwdYNFKbMv
Tip of trunk gcc gives:
prog.cc: In function 'int main()':
prog.cc:10:28: error: cannot convert 'date::year' to 'int' in initialization
auto y = int{ymd.year()};
^
clang prints out the current year (UTC).
Changing the offending line to:
auto y = int(ymd.year());
is a workaround. But people really like the Uniform Initialization Syntax
(using braces).
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631 --- Comment #3 from Paul Dreik --- This is still present in trunk, rev 242335 g++-trunk (GCC) 7.0.0 20161112 (experimental)
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631
Paul Dreik changed:
What|Removed |Added
CC||gcc at pauldreik dot se
--- Comment #2 from Paul Dreik ---
This is still present in 6.2 (as packaged by Debian)
#67631.cpp is the code in Howard Hinnants comment 2015-09-18 20:51:59 UTC
paul@debian-stretch:~$ g++ -std=c++14 67631.cpp
67631.cpp: In instantiation of 'void test(const U&) [with T = unsigned int; U =
X]':
67631.cpp:34:24: required from here
67631.cpp:10:7: error: cannot convert 'const X' to 'unsigned int' in
initialization
t = T{uo};
~~^~~
paul@debian-stretch:~$ g++ --version
g++ (Debian 6.2.0-10) 6.2.0 20161027
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
[Bug c++/67631] brace initialization bug
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67631
Markus Trippelsdorf changed:
What|Removed |Added
Keywords||rejects-valid
Status|UNCONFIRMED |NEW
Last reconfirmed||2015-09-18
CC||trippels at gcc dot gnu.org
Ever confirmed|0 |1
Known to fail||4.9.2, 5.2.1, 6.0
--- Comment #1 from Markus Trippelsdorf ---
markus@x4 tmp % cat bra.ii
class X
{
public:
X (int);
explicit operator unsigned ();
};
unsigned
foo ()
{
return unsigned{ X (0) };
}
markus@x4 tmp % icpc -Wall -Wextra -c -std=c++14 bra.ii
markus@x4 tmp % clang++ -Wall -Wextra -c -std=c++14 bra.ii
markus@x4 tmp % g++ -Wall -Wextra -c -std=c++14 bra.ii
bra.ii: In function ‘unsigned int foo()’:
bra.ii:10:26: error: cannot convert ‘X’ to ‘unsigned int’ in initialization
return unsigned{ X (0) };
^
