https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71537
Bug ID: 71537
Summary: GCC rejects consetxpr boolean conversions and
comparisons on the result of pointer arithmetic.
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: eric at efcs dot ca
Target Milestone: ---
For example:
constexpr int n[42] = {1};
constexpr int x = n ? 1 : 0; // Accepted.
constexpr int xx = n + 1 ? 1 : 0; // Rejected
constexpr int xxx = "abc" + 1 ? 1 : 0; // Also Rejected
This has a significant impact on constexpr algorithms which operate over raw
pointers since pointer comparisons are not considered constant expressions.
For example this bug breaks libc++'s implementation of string_view::find and
renders the "char_traits<char>::find(...)" interface useless since it returns a
possibly null pointer.
