https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99700
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |msebor at gcc dot gnu.org
Summary|gcc takes an uninitialized |uninitialized variable
|variable as a constant |accepted as a constant
|expression |expression in C++ 20
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Last reconfirmed| |2021-04-15
--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Confirmed with -std=c++20. In earlier modes GCC rejects the test case as
expected.
$ (set -x && gcc -O2 -S -Wall -std=c++20 pr99700.C && gcc -O2 -S -Wall
-std=c++17 pr99700.C)
+ gcc -O2 -S -Wall -std=c++20 pr99700.C
+ gcc -O2 -S -Wall -std=c++17 pr99700.C
pr99700.C: In constructor ‘constexpr A::A()’:
pr99700.C:2:29: error: member ‘A::c’ must be initialized by mem-initializer in
‘constexpr’ constructor
2 | constexpr A() { c[0] = 0; }
| ^
pr99700.C:3:8: note: declared here
3 | char c[2];
| ^
pr99700.C: At global scope:
pr99700.C:6:13: error: ‘constexpr A::A()’ called in a constant expression
6 | constexpr A a;
| ^
pr99700.C:2:13: note: ‘constexpr A::A()’ declared here
2 | constexpr A() { c[0] = 0; }
| ^
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