I have been reading the Julia Documentation, and also some blogs on the internet, and I have found sentences that mention the concept of instantiation, for instance, "Int64 can be instantiated". I found some information on this concept here:
https://www.computerhope.com/jargon/i/instantiation.htm
but I cannot see how this could be used in Julia or why it is relevant. Any comment would be welcome. Thanks.
We say that type can be instantiated if it is possible to create an object that has this type.
For example Int64 can be instantiated as e.g. 1 on a 64-bit machine by default has this type:
julia> typeof(1)
Int64
However, a supertype of Int64 is Signed:
julia> supertype(Int64)
Signed
The Signed type cannot be instantiated, because it is abstract (see https://docs.julialang.org/en/v1/manual/types/#man-abstract-types). This means that it is impossible to create an object that has type Signed.