https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87982
Bug ID: 87982
Summary: No error for std::generate_n(ptr, ptr, f)
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Keywords: accepts-invalid
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
Target Milestone: ---
#include <algorithm>
int main()
{
int a[2];
std::generate_n(a, a+2, []{ return 0;});
}
This compiles without error, but crashes at runtime.
The code should use std::generate(a, a+2, f) or std::generate_n(a, 2, f).
With -Wextra -Wsystem-headers there's a clue something is wrong, but it doesn't
make the problem clear:
In file included from /usr/include/c++/7/algorithm:62:0,
from gn.cc:1:
/usr/include/c++/7/bits/stl_algo.h: In instantiation of ‘_OIter
std::generate_n(_OIter, _Size, _Generator) [with _OIter = int*; _Size = int*;
_Generator = main()::<lambda()>]’:
gn.cc:6:41: required from here
/usr/include/c++/7/bits/stl_algo.h:4467:13: warning: ordered comparison of
pointer with integer zero [-Wextra]
__niter > 0; --__niter, ++__first)
~~~~~~~~^~~
