A string is immutable, a byte slice is not.
Suppose you have:
b := []byte("hello world")
s := string(b)
fmt.Println(s)
b[0] = 'H'
fmt.Println(s)
What is printed?
hello world
hello word
Using the OPs function:
b := []byte("hello world")
s := fastBytesToString(b)
fmt.Println(s)
b[0] = 'H'
fmt.Println(s)
This results in
hello world
Hello world
So the immutable string pointed to by s has been mutated, so this program
violates Go's memory model.
"casting" a byte slice to/from a string involves a memory allocation and
copy, to be valid Go.
-Paul
On Mon, Sep 19, 2016 at 3:33 PM, 'simon place' via golang-nuts <
[email protected]> wrote:
> i thought strings were just byte[]s, when you 'cast' all you do is tell
> the compiler to change the way the underlying bytes can are used. it
> doesn't 'cost' anything.
>
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