With C++17 we get another facility to handle the conversion between text and numbers. Why should we care about the new routines? Are they better in any way?
from_chars is low-level, and offers the best possible performance.
Hooray! Had no idea this was a feature, thanks for sharing. Surprised only VC2017 fully supports it. Probably will be a while before it is stable on MinGW, since that lags behind further.