Due to the SettingsController being a static object it will be
initialized before the main method has been run. This will cause
easylogging to log using the default logging style instead of the
defined application style. Because of this the settings are propogated
up through a function into the main method.
After looking at the assembly output it became apparent that the Windows
compiler did not compile out the `getSettingsController()` function
call.
This led to an unnecessary function call in order to get the
SettingsController. Turning it into a static object in the compilation
unit scope removes this function call and turns getSettings call into a
single instruction (not counting zeroing the register for comparison and
the jump instruction afterwards).
----
Adding the following code to the `main` function:
```cpp
f ( settings::getSetting( settings::BoolSetting::UTILITY_vrcDebug ) )
{
LOG( INFO ) << "Enabled";
}
else
{
LOG( INFO ) << "Disabled";
}
```
Leads to this with the `getSettingsController` function:
```assembly
[...]
47 if ( settings::getSetting( settings::BoolSetting::UTILITY_vrcDebug ) )
0x7ff6c96819a0 <+ 1024> call AdvancedSettings!settings::getSettingsController (00007ff6`c96cd280)
0x7ff6c96819a5 <+ 1029> xorps xmm0,xmm0
0x7ff6c96819a8 <+ 1032> cmp byte ptr [rax+5FCh],0
0x7ff6c96819af <+ 1039> je AdvancedSettings!main+0x4fd (00007ff6`c9681a9d)
49 LOG( INFO ) << "Enabled";
0x7ff6c96819b5 <+ 1045> mov qword ptr
[rsp+288h],r15
0x7ff6c96819bd <+ 1053> mov qword ptr
[rsp+290h],rsi
[...]
```
And this without the function:
```assembly
[...]
47 if ( settings::getSetting( settings::BoolSetting::UTILITY_vrcDebug ) )
0x7ff7d97a19bb <+ 1019> xorps xmm0,xmm0
0x7ff7d97a19be <+ 1022> cmp byte ptr [AdvancedSettings!settings::settingController+0x5fc (00007ff7`d9854d4c)],0
0x7ff7d97a19c5 <+ 1029> je AdvancedSettings!main+0x4f3 (00007ff7`d97a1ab3)
49 LOG( INFO ) << "Enabled";
0x7ff7d97a19cb <+ 1035> mov qword ptr
[rsp+288h],r15
0x7ff7d97a19d3 <+ 1043> mov qword ptr
[rsp+290h],rsi
[...]
```
Notice the missing `call AdvancedSettings![...]` without the function
and that the settings call literally cannot be made any faster.
The details of the API are in the `/docs/specsSettings-API.md` file.
The enums do not list all available settings, more are to be added as
the settings API replaces inline QSettings calls.
Vasily