The storage of a pointer means that the ownership and lifetime are
externally determined, which is harder to reason about. It also imposes
API constraints, requiring APIs to return references to backtraces.
This pointer storage was introduced in commit v3.1.0-rc1~425^2~3 (genex:
remove the need for backtraces, 2014-05-23). As backtraces are now cheap
to copy around, just do that instead.
013ada80 cmPolicies: Implement PolicyMap in terms of bitset.
be6664c2 cmPolicies: Implement abstraction for PolicyMap.
de211686 Port to static cmPolicies API.
13981f20 cmPolicies: Make all API static.
23e2bcc8 cmPolicies: Remove unused DefinePolicy method.
5641ba4f cmPolicies: Remove unused cmPolicy class.
3de54497 cmPolicies: Loop over all policies using enum constants.
387aff20 cmPolicies: Trivialize GetPolicyStatus method.
dbf680d6 cmPolicies: Use more-direct ID access.
8c204133 cmPolicies: Implement in terms of public API.
e3a8c029 cmPolicies: Make private method file-static.
cb765af0 cmPolicies: Implement short description access with XMacros.
5df267fa cmPolicies: Implement version check with XMacro.
2235cfeb cmPolicies: Implement id to version with XMacro.
05d84388 cmPolicies: Implement id to string conversion with XMacro.
6eaade8a cmPolicies: Introduce XMacro table for policy data.
...