On 10/05/18 00:37, Peter Dimov via Boost wrote:
- identifier-based category comparison
This states in Motivation that "relying on address-based comparisons makes it impossible to declare category objects constexpr and makes it impossible to declare operator< constexpr" Implementation adds the constexpr to operator< "constexpr bool operator<(const error_category& rhs) const noexcept;" with an as-if comment about the return value, which ends with an address comparison: "return less<const error_category*>()(this, &rhs);" How can this be made constexpr?
- message() into a caller-supplied buffer
This document refers to strerror_r as a glibc thing. It is also Posix, which is probably a better reference: http://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror.html Other than that, I very much agree with your proposals.