SDH, I can't tell what you really meant with all the things you listed.
- C++11: std::to_string ...
So, why can't you just use std::to_string then?
- Network: nat hole punching, define packets ttl, timestamp
NAT hole punching isn't something you can just "enable" between 2 parties, it always consists of at least one party that doesn't require hole punching e.g. an internet server and the parties that do. So in case the 2 parties who are both trying to communicate behind each other are behind NAT gateways, you will need a publicly accessible server somewhere in the internet. This is really not a feature any more, but rather a concrete use case.
I don't see any reason to be able to define a packets TTL. TTL is meant to prevent packets from travelling the internet forever. Besides that, the only reason to be able to manually set it is for diagnostic purposes e.g. traceroute. In normal cases, you can rely on the operating system setting the TTL value properly.
I also don't understand what you mean by "timestamp". If you want to add a timestamp to your packets, then you can already do so. What does this have to do with being a new feature?
- Graphics: motion blur shader, shake screen
These are post-processing effects which are already possible with sf::Shader.
- Global: "inline" for short functions [like getPosition(), getRotation() ...etc]
If you enable optimizations, you will find that more often than not, the compiler is smart enough to inline calls
where they make sense. The opposite is also true,
they don't inline where it doesn't make sense, even if the function is marked inline by the programmer. In the end it is only a hint, and a good optimizer shouldn't need that many hints to produce a program that runs fast, even without explicit inlines.
- System: add precise clock: std::chrono
So, do you want SFML to replicate std::chrono? Is there a reason you would rather use SFML's sf::Clock rather than std::chrono? Currently, SFML's clock
might even have a higher resolution than std::chrono's high_resolution_clock, so I don't understand what exactly you are requesting.