Under no circumstance must Qt code define a non-public qHash()
overload of a public Qt type. If you can't provide a public qHash()
for the type, you can't use QHash. Period. This is because if we don't
provide a qHash() function, the user will have to provide one, and
then we have an ODR violation, iow: UB.
So, port away from QHash and qHash and use std::unordered_map, which
allows to pass a custom hash function - just what we needed.
Also fix other issues of the code:
- Use a function object as the deleter of the QSharedPointer, to allow
inlining the function call.
- Avoid double lookup in case of a cache miss.
- Don't use direct initialization syntax for pointer variables. That's
just ... weird.
Change-Id: Ica8bff728c1bd1cbb2fb43aa03a99bcb7ac2f7cc
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
2596a8a55c