当我们说uintptr存储指针值的未解释位是什么意思？

Question

I read in golang website that uintptr stores the uninterpreted bits of a pointer value, the kind of anwsers that i found on web were very confusing.Can someone please explaing this to me in simple words .

Answer 1

Short answer: it's used when you need to use an address as if it's a number.

Go is a garbage-collected language. Go always knows exactly, when a thing is a pointer, and when it's just a value. Go needs this knowledge to look for old unused values that it can free. Pointers are also special in Go in that you can't just add a number to a pointer like you would do in C.

But sometimes, when you work with embedded systems or some kind of low-level libraries where you need to add or subtract from an address, you need to tell Go that it shouldn't check this pointer because it's not pointing to anything useful at the moment. You just want to use this address as if it was a number and add/subtract another number to it.

This is where you would use uintptr. This type can hold any pointer value (any address), and when you put an address into it, Go doesn't see it as a pointer, so you can do whatever you want with it.