Implicit error_type from ErrorCondEnum constructor. Calls void on_result_construction(T *, U &&) noexcept with this and ErrorCondEnum.

Requires: predicate::enable_error_condition_converting_constructor<R> is true.

Complexity: Same as for error_type’s copy or move constructor from the result of make_error_code(ErrorCondEnum). Constexpr, triviality and noexcept of underlying operations is propagated.

Guarantees: If an exception is thrown during the operation, the state of the input is left indeterminate.