This roughly corresponds to my experience with Erlang; keeping in mind that "D" in Erlang relies heavily on its OTP ecosystem, which is fairly complex and different from most other languages.
Ignoring OTP, my ability to use the language proper was pretty much complete within a week, owing to its simplicity and my prior background in functional languages.
This is in contrast to C, which I have been using for around 15 years now, yet am still learning nuances of the language. (Things like: which integer operations are undefined on negative numbers; how integer promotion works with shift operators; how "restrict" interacts with scope.)
C is almost a fractal of nuance that does take years of experience to comprehend; Erlang has no nuance. (The closest thing to nuance I can think of is the relationship between integers and floats; and even then the takeaway is "it just works; don't worry about it". The only language in which I've seen the number hierarchy handled more cleanly is Racket.)
Ignoring OTP, my ability to use the language proper was pretty much complete within a week, owing to its simplicity and my prior background in functional languages.
This is in contrast to C, which I have been using for around 15 years now, yet am still learning nuances of the language. (Things like: which integer operations are undefined on negative numbers; how integer promotion works with shift operators; how "restrict" interacts with scope.)
C is almost a fractal of nuance that does take years of experience to comprehend; Erlang has no nuance. (The closest thing to nuance I can think of is the relationship between integers and floats; and even then the takeaway is "it just works; don't worry about it". The only language in which I've seen the number hierarchy handled more cleanly is Racket.)