https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108363
Bug ID: 108363
Summary: Narrowing conversion errors are suppressed with the -w
flag
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: novulae at hotmail dot com
Target Milestone: ---
I ran across this with GCC 12.2.0, but have confirmed that it still reproduces
with trunk via Godbolt.
With the below test case, a narrowing error is expected, and is indeed offered
by GCC. However, when warnings are suppressed, the error is suppressed as well.
$ cat test.cpp
template<bool> struct X {
using m = int;
};
template<typename>
using Y = X< sizeof(int) >::m;
$ g++ -c -w -std=c++20 test.cpp
$ g++ -c -std=c++20 test.cpp
test.cpp:6:26: error: narrowing conversion of ‘4’ from ‘long unsigned int’ to
‘bool’ [-Wnarrowing]
6 | using Y = X< sizeof(int) >::m;
| ^
Clang issues a corresponding error both with and without -w.
