https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110028
Bug ID: 110028
Summary: slow compilation on incorrect namespace after gcc-12.1
Product: gcc
Version: 12.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: stevenxia990430 at gmail dot com
Target Milestone: ---
The following program is very slow to compile (>10 seconds) and return error.
Compared to clang (<1 second).
To quickly reproduce: https://gcc.godbolt.org/z/Pfrxcdb9h
```
#include <span>
#include <vector>
namespace test
{
#include <algorithm>
std::size_t filter_odd_elements(std::span<long> array)
{
std::size_t index = 0;
std::copy_if(array.rbegin(), array.rend(), array.begin(), [&](long value)
{
return (++index) % 2 == 1;
});
return index;
}
}
int main() {
}
```
Tested on Trunk and it seems that the slow compilation rate occured after and
including gcc 12.1
