https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106175
Bug ID: 106175
Summary: std::prev and next should check for equality with
std::begin
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: deco33000 at yandex dot com
Target Milestone: ---
Hi,
To get better defined algorithms, we should not have a segfault in that case:
int main()
{
std::vector<int> v;
// if (v.empty()) {return;}; <- should not need that line
for (auto i = begin(v); i != prev(end(v)); i += 1){
std::cout << *i << std::endl;
}
return 0;
}
std::prev should always check for equality with begin() or empty() for its
argument.
If equal, do nothing to the iterator. The loop won't be entered.
Same for std::next, and by extension std::advance.
if we need to do specific actions in case the vector is empty, that is an
opt-in decision.
There may be some good counter arguments but I don't see them..
