Before we dive into regions of memory, you first need to know about the difference between values, variables, and pointers.
A value in Rust is the combination of a type and an element of that type’s domain of values.
A value can be turned into a sequence of bytes using its type’s representation.
| Value | Type | Memory Representation |
|---|---|---|
| 6 | u8 | 0x06 |
A value is stored in a place, which is the Rust terminology for “a location that can hold a value.” This place can be on the stack, on the heap, or in a number of other locations. The most common place to store a value is a variable, which is a named value slot on the stack.
A pointer is a value that holds the address of a region of memory, so the pointer points to a place.
We can store the same pointer in more than one variable and therefore have multiple variables that indirectly refer to the same location in memory and thus the same underlying value
A pointer can be dereferenced to access the value stored in the memory location it points to.
let string = 'Hello world'; Even though we assign a string value to the variable string, the actual value of the variable is a pointer to the first character in the string value ‘Hello world’, and not the string value itself.