https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87292
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2018-09-13
Ever confirmed|0 |1
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Nuno Gonçalves from comment #4)
> I found that the issue with enum have been extensively debated at #61414.
> Sorry.
Yes, we already have Bug 61414 for that.
> So actually this bug report is only regarding the warning with initializer
> list:
>
> struct{
> uint8_t c1:6;
> uint8_t c2:6;
> } a;
> auto c = {a.c1, a.c2}; //warning: narrowing conversion of '(unsigned
> char)c1' from 'unsigned char' to 'unsigned char:6' [-Wnarrowing]
Confirmed. The initializers should be promoted before deciding the type of the
std::initializer_list.
This should compile:
#include <initializer_list>
struct {
int c1 : 6;
int c2 : 6;
} a;
auto c = { a.c1, a.c2 };
std::initializer_list<int>& r = c;
n.cc:7:14: warning: narrowing conversion of '(int)a.<unnamed struct>::c1' from
'int' to 'signed char:6' [-Wnarrowing]
7 | auto c = { a.c1, a.c2 };
| ~~^~
n.cc:7:14: warning: narrowing conversion of 'a.<unnamed struct>::c1' from 'int'
to 'signed char:6' [-Wnarrowing]
n.cc:7:20: warning: narrowing conversion of '(int)a.<unnamed struct>::c2' from
'int' to 'signed char:6' [-Wnarrowing]
7 | auto c = { a.c1, a.c2 };
| ~~^~
n.cc:7:20: warning: narrowing conversion of 'a.<unnamed struct>::c2' from 'int'
to 'signed char:6' [-Wnarrowing]
n.cc:8:33: error: invalid initialization of reference of type
'std::initializer_list<int>&' from expression of type
'std::initializer_list<signed char:6>'
8 | std::initializer_list<int>& r = c;
|
