Optimize str_format(…, …, "%d", …) using templates

[heinrich5991]

This would make the function str_from_int unnecessary, at least user-facing.

Advantage: User doesn't have to care about str_from_int/str_format distinction.

Disadvantage: We're adding some template programming to system.h, potentially slowing all compilation.

Checklist

• Tested the change ingame
• Provided screenshots if it is a visual change
• Tested in combination with possibly related configuration options
• Written a unit test (especially base/) or added coverage to integration test
• Considered possible null pointers and out of bounds array indexing
• Changed no physics that affect existing maps
• Tested the change with ASan+UBSan or valgrind's memcheck (optional)

[heinrich5991]

@Learath2 @Robyt3 Do we want something like this?

[Learath2]

I like it. I'm curious if this gets optimized out properly to a direct call for compile time constant format strings

[heinrich5991]

I checked with all major compilers on Godbolt and this is what I ended up with. It gets optimized out properly for compile-time constant format strings.

[Chairn]

This looks like over optimization. What happens if the string is " %d" or "%d\n" or even any other format like %lld or %u ?

[heinrich5991]

This looks like over optimization. What happens if the string is " %d" or "%d\n" or even any other format like %lld or %u ?

It doesn't work in this case. What I'd like to avoid is humans having to remember to call str_from_int. This function was introduced for measurable performance impact (#7056):

This increases FPS in the editor by ~25% when many numbers are rendered for switch/tele/speedup/tune layers or with "Show Info" being enabled.

[Robyt3]

Looks good. I prefer this over having a separate str_from_int.