Make the constructors of `IdTable` SFINAE-friendly

[joka921]

Previously std::is_default_constructible<IdTable> was true, but trying to default-construct an IdTable led to a hard compiler error, as the used allocator (the AllocatorWithLimit) was not default constructible. This is now fixed by adding the proper constraints to the constructors of the IdTable class.

[joka921]

@RobinTF Please try it out, and tell me if that solves your strange compilation issues on MacOS.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 89.52%. Comparing base (e1cf7d0) to head (f097730). Report is 6 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1479 +/- ## ========================================== + Coverage 89.50% 89.52% +0.02% ========================================== Files 347 347 Lines 25579 25590 +11 Branches 3439 3440 +1 ========================================== + Hits 22895 22910 +15 + Misses 1494 1493 -1 + Partials 1190 1187 -3 ```

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[RobinTF]

That seems to do the trick, thank you.

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud