[Bug libstdc++/125878] Some search algorithms form called with execution policies fail to produce correct result.

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125878

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2026-06-19
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Reduced to a rejects-valid test:

#include <algorithm>
#include <execution>

int main()
{
  auto cmp = [](auto x, auto y) {
    static_assert(std::is_same_v<decltype(x), int>);
    static_assert(std::is_same_v<decltype(y), long>);
    return x == y;
  };
  int i[2]{};
  long l[2]{};
  (void) std::find_end(i, i+2, l, l+2, cmp);
  (void) std::find_end(std::execution::seq, i, i+2, l, l+2, cmp);
  (void) std::find_end(std::execution::par, i, i+2, l, l+2, cmp);
  (void) std::find_end(std::execution::par_unseq, i, i+2, l, l+2, cmp);

  (void) std::find_first_of(i, i+2, l, l+2, cmp);
  (void) std::find_first_of(std::execution::seq, i, i+2, l, l+2, cmp);
  (void) std::find_first_of(std::execution::par, i, i+2, l, l+2, cmp);
  (void) std::find_first_of(std::execution::par_unseq, i, i+2, l, l+2, cmp);
}