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[go/en] Clarify safety of local variable address taking.

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Petr Houška 2020-02-08 22:57:43 +01:00 committed by GitHub
parent e021d05c2f
commit 3869472f74
1 changed files with 2 additions and 1 deletions
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@ -168,10 +168,11 @@ func learnNamedReturns(x, y int) (z int) {
// Go is fully garbage collected. It has pointers but no pointer arithmetic. // Go is fully garbage collected. It has pointers but no pointer arithmetic.
// You can make a mistake with a nil pointer, but not by incrementing a pointer. // You can make a mistake with a nil pointer, but not by incrementing a pointer.
// Unlike in C/Cpp taking and returning an address of a local varible is also safe.
func learnMemory() (p, q *int) { func learnMemory() (p, q *int) {
// Named return values p and q have type pointer to int. // Named return values p and q have type pointer to int.
p = new(int) // Built-in function new allocates memory. p = new(int) // Built-in function new allocates memory.
// The allocated int is initialized to 0, p is no longer nil. // The allocated int slice is initialized to 0, p is no longer nil.
s := make([]int, 20) // Allocate 20 ints as a single block of memory. s := make([]int, 20) // Allocate 20 ints as a single block of memory.
s[3] = 7 // Assign one of them. s[3] = 7 // Assign one of them.
r := -2 // Declare another local variable. r := -2 // Declare another local variable.