Go 1.21 RC brings language improvements, new standard library packages, PGO GA, backward and forward compatibility in the toolchain and faster builds.
Go 1.21 release candidate is available.
It has some interesting changes in my opinion:
clear() for clearing maps
new slices package for common operations on slices
new maps package for cloning and comparing maps
And some somewhat interesting ones:
min/max function directly in the language without a package (could have easily been in math package, but then again, you can min/max strings with this?)
Not easily while not avoiding the allocation hit of variadic arguments. But funny that, after all these years waiting on parametric polymorphism to be able to add a generalized min/max, it ends up as a built-in anyway.