simplify key constraint

README.md

@@ -16,7 +16,7 @@ bug that can cause writes to be lost.***
 
 ## Usage
 
-Only Go built-in types beside any/interface{} are supported.
+Only Go comparable types are supported as keys.
 
 Set a value for a key in the map:
 

hashmap.go

@@ -16,13 +16,8 @@ const DefaultSize = 8
 // MaxFillRate is the maximum fill rate for the slice before a resize  will happen.
 const MaxFillRate = 50
 
-type keyConstraint interface {
-	string | int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | uintptr |
-		float32 | float64 | complex64 | complex128
-}
-
 // HashMap implements a read optimized hash map.
-type HashMap[Key keyConstraint, Value any] struct {
+type HashMap[Key comparable, Value any] struct {
 	hasher     func(Key) uintptr
 	store      atomic.Pointer[store[Key, Value]] // pointer to a map instance that gets replaced if the map resizes
 	linkedList atomic.Pointer[List[Key, Value]]  // key sorted linked list of elements
@@ -32,18 +27,18 @@ type HashMap[Key keyConstraint, Value any] struct {
 }
 
 // KeyValue represents a key/value that is returned by the iterator.
-type KeyValue[Key keyConstraint, Value any] struct {
+type KeyValue[Key comparable, Value any] struct {
 	Key   Key
 	Value Value
 }
 
 // New returns a new HashMap instance.
-func New[Key keyConstraint, Value any]() *HashMap[Key, Value] {
+func New[Key comparable, Value any]() *HashMap[Key, Value] {
 	return NewSized[Key, Value](DefaultSize)
 }
 
 // NewSized returns a new HashMap instance with a specific initialization size.
-func NewSized[Key keyConstraint, Value any](size uintptr) *HashMap[Key, Value] {
+func NewSized[Key comparable, Value any](size uintptr) *HashMap[Key, Value] {
 	m := &HashMap[Key, Value]{}
 	m.allocate(size)
 	m.setHasher()

list.go

@@ -5,13 +5,13 @@ import (
 )
 
 // List is a sorted doubly linked list.
-type List[Key keyConstraint, Value any] struct {
+type List[Key comparable, Value any] struct {
 	count atomic.Uintptr
 	head  *ListElement[Key, Value]
 }
 
 // NewList returns an initialized list.
-func NewList[Key keyConstraint, Value any]() *List[Key, Value] {
+func NewList[Key comparable, Value any]() *List[Key, Value] {
 	return &List[Key, Value]{
 		head: &ListElement[Key, Value]{},
 	}

list_element.go

@@ -5,7 +5,7 @@ import (
 )
 
 // ListElement is an element of a list.
-type ListElement[Key keyConstraint, Value any] struct {
+type ListElement[Key comparable, Value any] struct {
 	keyHash uintptr
 	// deleted marks the item as deleting or deleted
 	// this is using uintptr instead of atomic.Bool to avoid using 32 bit int on 64 bit systems

store.go

@@ -5,7 +5,7 @@ import (
 	"unsafe"
 )
 
-type store[Key keyConstraint, Value any] struct {
+type store[Key comparable, Value any] struct {
 	keyShifts uintptr                    // Pointer size - log2 of array size, to be used as index in the data array
 	count     atomic.Uintptr             // count of filled elements in the slice
 	array     unsafe.Pointer             // pointer to slice data array