diff --git a/cache.go b/cache.go
index 3562543..213e180 100644
--- a/cache.go
+++ b/cache.go
@@ -1,17 +1,14 @@
 package cache
 
 import (
-	"encoding/gob"
 	"fmt"
-	"io"
-	"os"
 	"runtime"
 	"sync"
 	"time"
 )
 
 type Item struct {
-	Object     interface{}
+	Object     ValueType
 	Expiration int64
 }
 
@@ -41,14 +38,14 @@ type cache struct {
 	defaultExpiration time.Duration
 	items             map[string]Item
 	mu                sync.RWMutex
-	onEvicted         func(string, interface{})
+	onEvicted         func(string, *ValueType)
 	janitor           *janitor
 }
 
 // Add an item to the cache, replacing any existing item. If the duration is 0
 // (DefaultExpiration), the cache's default expiration time is used. If it is -1
 // (NoExpiration), the item never expires.
-func (c *cache) Set(k string, x interface{}, d time.Duration) {
+func (c *cache) Set(k string, x ValueType, d time.Duration) {
 	// "Inlining" of set
 	var e int64
 	if d == DefaultExpiration {
@@ -67,7 +64,7 @@ func (c *cache) Set(k string, x interface{}, d time.Duration) {
 	c.mu.Unlock()
 }
 
-func (c *cache) set(k string, x interface{}, d time.Duration) {
+func (c *cache) set(k string, x ValueType, d time.Duration) {
 	var e int64
 	if d == DefaultExpiration {
 		d = c.defaultExpiration
@@ -83,7 +80,7 @@ func (c *cache) set(k string, x interface{}, d time.Duration) {
 
 // Add an item to the cache only if an item doesn't already exist for the given
 // key, or if the existing item has expired. Returns an error otherwise.
-func (c *cache) Add(k string, x interface{}, d time.Duration) error {
+func (c *cache) Add(k string, x ValueType, d time.Duration) error {
 	c.mu.Lock()
 	_, found := c.get(k)
 	if found {
@@ -97,7 +94,7 @@ func (c *cache) Add(k string, x interface{}, d time.Duration) error {
 
 // Set a new value for the cache key only if it already exists, and the existing
 // item hasn't expired. Returns an error otherwise.
-func (c *cache) Replace(k string, x interface{}, d time.Duration) error {
+func (c *cache) Replace(k string, x ValueType, d time.Duration) error {
 	c.mu.Lock()
 	_, found := c.get(k)
 	if !found {
@@ -111,25 +108,25 @@ func (c *cache) Replace(k string, x interface{}, d time.Duration) error {
 
 // Get an item from the cache. Returns the item or nil, and a bool indicating
 // whether the key was found.
-func (c *cache) Get(k string) (interface{}, bool) {
+func (c *cache) Get(k string) *ValueType {
 	c.mu.RLock()
 	// "Inlining" of get and Expired
 	item, found := c.items[k]
 	if !found {
 		c.mu.RUnlock()
-		return nil, false
+		return nil
 	}
 	if item.Expiration > 0 {
 		if time.Now().UnixNano() > item.Expiration {
 			c.mu.RUnlock()
-			return nil, false
+			return nil
 		}
 	}
 	c.mu.RUnlock()
-	return item.Object, true
+	return &item.Object
 }
 
-func (c *cache) get(k string) (interface{}, bool) {
+func (c *cache) get(k string) (*ValueType, bool) {
 	item, found := c.items[k]
 	if !found {
 		return nil, false
@@ -140,7 +137,7 @@ func (c *cache) get(k string) (interface{}, bool) {
 			return nil, false
 		}
 	}
-	return item.Object, true
+	return &item.Object, true
 }
 
 // Increment an item of type int, int8, int16, int32, int64, uintptr, uint,
@@ -148,723 +145,23 @@ func (c *cache) get(k string) (interface{}, bool) {
 // item's value is not an integer, if it was not found, or if it is not
 // possible to increment it by n. To retrieve the incremented value, use one
 // of the specialized methods, e.g. IncrementInt64.
+// TODO: Increment for numberic type.
 func (c *cache) Increment(k string, n int64) error {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return fmt.Errorf("Item %s not found", k)
-	}
-	switch v.Object.(type) {
-	case int:
-		v.Object = v.Object.(int) + int(n)
-	case int8:
-		v.Object = v.Object.(int8) + int8(n)
-	case int16:
-		v.Object = v.Object.(int16) + int16(n)
-	case int32:
-		v.Object = v.Object.(int32) + int32(n)
-	case int64:
-		v.Object = v.Object.(int64) + n
-	case uint:
-		v.Object = v.Object.(uint) + uint(n)
-	case uintptr:
-		v.Object = v.Object.(uintptr) + uintptr(n)
-	case uint8:
-		v.Object = v.Object.(uint8) + uint8(n)
-	case uint16:
-		v.Object = v.Object.(uint16) + uint16(n)
-	case uint32:
-		v.Object = v.Object.(uint32) + uint32(n)
-	case uint64:
-		v.Object = v.Object.(uint64) + uint64(n)
-	case float32:
-		v.Object = v.Object.(float32) + float32(n)
-	case float64:
-		v.Object = v.Object.(float64) + float64(n)
-	default:
-		c.mu.Unlock()
-		return fmt.Errorf("The value for %s is not an integer", k)
-	}
-	c.items[k] = v
-	c.mu.Unlock()
 	return nil
 }
 
-// Increment an item of type float32 or float64 by n. Returns an error if the
-// item's value is not floating point, if it was not found, or if it is not
-// possible to increment it by n. Pass a negative number to decrement the
-// value. To retrieve the incremented value, use one of the specialized methods,
-// e.g. IncrementFloat64.
-func (c *cache) IncrementFloat(k string, n float64) error {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return fmt.Errorf("Item %s not found", k)
-	}
-	switch v.Object.(type) {
-	case float32:
-		v.Object = v.Object.(float32) + float32(n)
-	case float64:
-		v.Object = v.Object.(float64) + n
-	default:
-		c.mu.Unlock()
-		return fmt.Errorf("The value for %s does not have type float32 or float64", k)
-	}
-	c.items[k] = v
-	c.mu.Unlock()
-	return nil
-}
-
-// Increment an item of type int by n. Returns an error if the item's value is
-// not an int, or if it was not found. If there is no error, the incremented
-// value is returned.
-func (c *cache) IncrementInt(k string, n int) (int, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type int8 by n. Returns an error if the item's value is
-// not an int8, or if it was not found. If there is no error, the incremented
-// value is returned.
-func (c *cache) IncrementInt8(k string, n int8) (int8, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int8)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int8", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type int16 by n. Returns an error if the item's value is
-// not an int16, or if it was not found. If there is no error, the incremented
-// value is returned.
-func (c *cache) IncrementInt16(k string, n int16) (int16, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int16)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int16", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type int32 by n. Returns an error if the item's value is
-// not an int32, or if it was not found. If there is no error, the incremented
-// value is returned.
-func (c *cache) IncrementInt32(k string, n int32) (int32, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int32)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int32", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type int64 by n. Returns an error if the item's value is
-// not an int64, or if it was not found. If there is no error, the incremented
-// value is returned.
-func (c *cache) IncrementInt64(k string, n int64) (int64, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int64)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int64", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type uint by n. Returns an error if the item's value is
-// not an uint, or if it was not found. If there is no error, the incremented
-// value is returned.
-func (c *cache) IncrementUint(k string, n uint) (uint, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type uintptr by n. Returns an error if the item's value
-// is not an uintptr, or if it was not found. If there is no error, the
-// incremented value is returned.
-func (c *cache) IncrementUintptr(k string, n uintptr) (uintptr, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uintptr)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uintptr", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type uint8 by n. Returns an error if the item's value
-// is not an uint8, or if it was not found. If there is no error, the
-// incremented value is returned.
-func (c *cache) IncrementUint8(k string, n uint8) (uint8, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint8)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint8", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type uint16 by n. Returns an error if the item's value
-// is not an uint16, or if it was not found. If there is no error, the
-// incremented value is returned.
-func (c *cache) IncrementUint16(k string, n uint16) (uint16, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint16)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint16", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type uint32 by n. Returns an error if the item's value
-// is not an uint32, or if it was not found. If there is no error, the
-// incremented value is returned.
-func (c *cache) IncrementUint32(k string, n uint32) (uint32, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint32)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint32", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type uint64 by n. Returns an error if the item's value
-// is not an uint64, or if it was not found. If there is no error, the
-// incremented value is returned.
-func (c *cache) IncrementUint64(k string, n uint64) (uint64, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint64)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint64", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type float32 by n. Returns an error if the item's value
-// is not an float32, or if it was not found. If there is no error, the
-// incremented value is returned.
-func (c *cache) IncrementFloat32(k string, n float32) (float32, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(float32)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an float32", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Increment an item of type float64 by n. Returns an error if the item's value
-// is not an float64, or if it was not found. If there is no error, the
-// incremented value is returned.
-func (c *cache) IncrementFloat64(k string, n float64) (float64, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(float64)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an float64", k)
-	}
-	nv := rv + n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
 // Decrement an item of type int, int8, int16, int32, int64, uintptr, uint,
 // uint8, uint32, or uint64, float32 or float64 by n. Returns an error if the
 // item's value is not an integer, if it was not found, or if it is not
 // possible to decrement it by n. To retrieve the decremented value, use one
 // of the specialized methods, e.g. DecrementInt64.
+// TODO: Decrement
 func (c *cache) Decrement(k string, n int64) error {
 	// TODO: Implement Increment and Decrement more cleanly.
 	// (Cannot do Increment(k, n*-1) for uints.)
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return fmt.Errorf("Item not found")
-	}
-	switch v.Object.(type) {
-	case int:
-		v.Object = v.Object.(int) - int(n)
-	case int8:
-		v.Object = v.Object.(int8) - int8(n)
-	case int16:
-		v.Object = v.Object.(int16) - int16(n)
-	case int32:
-		v.Object = v.Object.(int32) - int32(n)
-	case int64:
-		v.Object = v.Object.(int64) - n
-	case uint:
-		v.Object = v.Object.(uint) - uint(n)
-	case uintptr:
-		v.Object = v.Object.(uintptr) - uintptr(n)
-	case uint8:
-		v.Object = v.Object.(uint8) - uint8(n)
-	case uint16:
-		v.Object = v.Object.(uint16) - uint16(n)
-	case uint32:
-		v.Object = v.Object.(uint32) - uint32(n)
-	case uint64:
-		v.Object = v.Object.(uint64) - uint64(n)
-	case float32:
-		v.Object = v.Object.(float32) - float32(n)
-	case float64:
-		v.Object = v.Object.(float64) - float64(n)
-	default:
-		c.mu.Unlock()
-		return fmt.Errorf("The value for %s is not an integer", k)
-	}
-	c.items[k] = v
-	c.mu.Unlock()
 	return nil
 }
 
-// Decrement an item of type float32 or float64 by n. Returns an error if the
-// item's value is not floating point, if it was not found, or if it is not
-// possible to decrement it by n. Pass a negative number to decrement the
-// value. To retrieve the decremented value, use one of the specialized methods,
-// e.g. DecrementFloat64.
-func (c *cache) DecrementFloat(k string, n float64) error {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return fmt.Errorf("Item %s not found", k)
-	}
-	switch v.Object.(type) {
-	case float32:
-		v.Object = v.Object.(float32) - float32(n)
-	case float64:
-		v.Object = v.Object.(float64) - n
-	default:
-		c.mu.Unlock()
-		return fmt.Errorf("The value for %s does not have type float32 or float64", k)
-	}
-	c.items[k] = v
-	c.mu.Unlock()
-	return nil
-}
-
-// Decrement an item of type int by n. Returns an error if the item's value is
-// not an int, or if it was not found. If there is no error, the decremented
-// value is returned.
-func (c *cache) DecrementInt(k string, n int) (int, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type int8 by n. Returns an error if the item's value is
-// not an int8, or if it was not found. If there is no error, the decremented
-// value is returned.
-func (c *cache) DecrementInt8(k string, n int8) (int8, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int8)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int8", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type int16 by n. Returns an error if the item's value is
-// not an int16, or if it was not found. If there is no error, the decremented
-// value is returned.
-func (c *cache) DecrementInt16(k string, n int16) (int16, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int16)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int16", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type int32 by n. Returns an error if the item's value is
-// not an int32, or if it was not found. If there is no error, the decremented
-// value is returned.
-func (c *cache) DecrementInt32(k string, n int32) (int32, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int32)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int32", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type int64 by n. Returns an error if the item's value is
-// not an int64, or if it was not found. If there is no error, the decremented
-// value is returned.
-func (c *cache) DecrementInt64(k string, n int64) (int64, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(int64)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an int64", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type uint by n. Returns an error if the item's value is
-// not an uint, or if it was not found. If there is no error, the decremented
-// value is returned.
-func (c *cache) DecrementUint(k string, n uint) (uint, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type uintptr by n. Returns an error if the item's value
-// is not an uintptr, or if it was not found. If there is no error, the
-// decremented value is returned.
-func (c *cache) DecrementUintptr(k string, n uintptr) (uintptr, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uintptr)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uintptr", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type uint8 by n. Returns an error if the item's value is
-// not an uint8, or if it was not found. If there is no error, the decremented
-// value is returned.
-func (c *cache) DecrementUint8(k string, n uint8) (uint8, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint8)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint8", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type uint16 by n. Returns an error if the item's value
-// is not an uint16, or if it was not found. If there is no error, the
-// decremented value is returned.
-func (c *cache) DecrementUint16(k string, n uint16) (uint16, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint16)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint16", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type uint32 by n. Returns an error if the item's value
-// is not an uint32, or if it was not found. If there is no error, the
-// decremented value is returned.
-func (c *cache) DecrementUint32(k string, n uint32) (uint32, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint32)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint32", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type uint64 by n. Returns an error if the item's value
-// is not an uint64, or if it was not found. If there is no error, the
-// decremented value is returned.
-func (c *cache) DecrementUint64(k string, n uint64) (uint64, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(uint64)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an uint64", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type float32 by n. Returns an error if the item's value
-// is not an float32, or if it was not found. If there is no error, the
-// decremented value is returned.
-func (c *cache) DecrementFloat32(k string, n float32) (float32, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(float32)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an float32", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
-// Decrement an item of type float64 by n. Returns an error if the item's value
-// is not an float64, or if it was not found. If there is no error, the
-// decremented value is returned.
-func (c *cache) DecrementFloat64(k string, n float64) (float64, error) {
-	c.mu.Lock()
-	v, found := c.items[k]
-	if !found || v.Expired() {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("Item %s not found", k)
-	}
-	rv, ok := v.Object.(float64)
-	if !ok {
-		c.mu.Unlock()
-		return 0, fmt.Errorf("The value for %s is not an float64", k)
-	}
-	nv := rv - n
-	v.Object = nv
-	c.items[k] = v
-	c.mu.Unlock()
-	return nv, nil
-}
-
 // Delete an item from the cache. Does nothing if the key is not in the cache.
 func (c *cache) Delete(k string) {
 	c.mu.Lock()
@@ -875,11 +172,11 @@ func (c *cache) Delete(k string) {
 	}
 }
 
-func (c *cache) delete(k string) (interface{}, bool) {
+func (c *cache) delete(k string) (*ValueType, bool) {
 	if c.onEvicted != nil {
 		if v, found := c.items[k]; found {
 			delete(c.items, k)
-			return v.Object, true
+			return &v.Object, true
 		}
 	}
 	delete(c.items, k)
@@ -888,7 +185,7 @@ func (c *cache) delete(k string) (interface{}, bool) {
 
 type keyAndValue struct {
 	key   string
-	value interface{}
+	value *ValueType
 }
 
 // Delete all expired items from the cache.
@@ -914,101 +211,12 @@ func (c *cache) DeleteExpired() {
 // Sets an (optional) function that is called with the key and value when an
 // item is evicted from the cache. (Including when it is deleted manually, but
 // not when it is overwritten.) Set to nil to disable.
-func (c *cache) OnEvicted(f func(string, interface{})) {
+func (c *cache) OnEvicted(f func(string, *ValueType)) {
 	c.mu.Lock()
 	c.onEvicted = f
 	c.mu.Unlock()
 }
 
-// Write the cache's items (using Gob) to an io.Writer.
-//
-// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
-// documentation for NewFrom().)
-func (c *cache) Save(w io.Writer) (err error) {
-	enc := gob.NewEncoder(w)
-	defer func() {
-		if x := recover(); x != nil {
-			err = fmt.Errorf("Error registering item types with Gob library")
-		}
-	}()
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	for _, v := range c.items {
-		gob.Register(v.Object)
-	}
-	err = enc.Encode(&c.items)
-	return
-}
-
-// Save the cache's items to the given filename, creating the file if it
-// doesn't exist, and overwriting it if it does.
-//
-// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
-// documentation for NewFrom().)
-func (c *cache) SaveFile(fname string) error {
-	fp, err := os.Create(fname)
-	if err != nil {
-		return err
-	}
-	err = c.Save(fp)
-	if err != nil {
-		fp.Close()
-		return err
-	}
-	return fp.Close()
-}
-
-// Add (Gob-serialized) cache items from an io.Reader, excluding any items with
-// keys that already exist (and haven't expired) in the current cache.
-//
-// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
-// documentation for NewFrom().)
-func (c *cache) Load(r io.Reader) error {
-	dec := gob.NewDecoder(r)
-	items := map[string]Item{}
-	err := dec.Decode(&items)
-	if err == nil {
-		c.mu.Lock()
-		defer c.mu.Unlock()
-		for k, v := range items {
-			ov, found := c.items[k]
-			if !found || ov.Expired() {
-				c.items[k] = v
-			}
-		}
-	}
-	return err
-}
-
-// Load and add cache items from the given filename, excluding any items with
-// keys that already exist in the current cache.
-//
-// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
-// documentation for NewFrom().)
-func (c *cache) LoadFile(fname string) error {
-	fp, err := os.Open(fname)
-	if err != nil {
-		return err
-	}
-	err = c.Load(fp)
-	if err != nil {
-		fp.Close()
-		return err
-	}
-	return fp.Close()
-}
-
-// Returns the items in the cache. This may include items that have expired,
-// but have not yet been cleaned up. If this is significant, the Expiration
-// fields of the items should be checked. Note that explicit synchronization
-// is needed to use a cache and its corresponding Items() return value at
-// the same time, as the map is shared.
-func (c *cache) Items() map[string]Item {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	return c.items
-}
-
 // Returns the number of items in the cache. This may include items that have
 // expired, but have not yet been cleaned up. Equivalent to len(c.Items()).
 func (c *cache) ItemCount() int {
@@ -1077,6 +285,9 @@ func newCacheWithJanitor(de time.Duration, ci time.Duration, m map[string]Item)
 	C := &Cache{c}
 	if ci > 0 {
 		runJanitor(c, ci)
+		// 如果C被回收了,但是c不会,因为stopJanitor是一个一直运行的
+		// goroutine对c一直有引用不会被回收,所以加一个Finalizer来停掉
+		// 这个goroutine然后让c被回收.
 		runtime.SetFinalizer(C, stopJanitor)
 	}
 	return C
@@ -1091,28 +302,3 @@ func New(defaultExpiration, cleanupInterval time.Duration) *Cache {
 	items := make(map[string]Item)
 	return newCacheWithJanitor(defaultExpiration, cleanupInterval, items)
 }
-
-// Return a new cache with a given default expiration duration and cleanup
-// interval. If the expiration duration is less than one (or NoExpiration),
-// the items in the cache never expire (by default), and must be deleted
-// manually. If the cleanup interval is less than one, expired items are not
-// deleted from the cache before calling c.DeleteExpired().
-//
-// NewFrom() also accepts an items map which will serve as the underlying map
-// for the cache. This is useful for starting from a deserialized cache
-// (serialized using e.g. gob.Encode() on c.Items()), or passing in e.g.
-// make(map[string]Item, 500) to improve startup performance when the cache
-// is expected to reach a certain minimum size.
-//
-// Only the cache's methods synchronize access to this map, so it is not
-// recommended to keep any references to the map around after creating a cache.
-// If need be, the map can be accessed at a later point using c.Items() (subject
-// to the same caveat.)
-//
-// Note regarding serialization: When using e.g. gob, make sure to
-// gob.Register() the individual types stored in the cache before encoding a
-// map retrieved with c.Items(), and to register those same types before
-// decoding a blob containing an items map.
-func NewFrom(defaultExpiration, cleanupInterval time.Duration, items map[string]Item) *Cache {
-	return newCacheWithJanitor(defaultExpiration, cleanupInterval, items)
-}
diff --git a/cache_test.go b/cache_test.go
index 6e81693..b0e077b 100644
--- a/cache_test.go
+++ b/cache_test.go
@@ -1,8 +1,6 @@
 package cache
 
 import (
-	"bytes"
-	"io/ioutil"
 	"runtime"
 	"strconv"
 	"sync"
@@ -18,58 +16,33 @@ type TestStruct struct {
 func TestCache(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
 
-	a, found := tc.Get("a")
-	if found || a != nil {
+	a := tc.Get("a")
+	if a != nil {
 		t.Error("Getting A found value that shouldn't exist:", a)
 	}
 
-	b, found := tc.Get("b")
-	if found || b != nil {
+	b := tc.Get("b")
+	if b != nil {
 		t.Error("Getting B found value that shouldn't exist:", b)
 	}
 
-	c, found := tc.Get("c")
-	if found || c != nil {
+	c := tc.Get("c")
+	if c != nil {
 		t.Error("Getting C found value that shouldn't exist:", c)
 	}
 
-	tc.Set("a", 1, DefaultExpiration)
-	tc.Set("b", "b", DefaultExpiration)
-	tc.Set("c", 3.5, DefaultExpiration)
+	tc.Set("a", ValueType(1), DefaultExpiration)
 
-	x, found := tc.Get("a")
-	if !found {
-		t.Error("a was not found while getting a2")
-	}
+	x := tc.Get("a")
 	if x == nil {
 		t.Error("x for a is nil")
-	} else if a2 := x.(int); a2+2 != 3 {
+	} else if a2 := int(*x); a2+2 != 3 {
 		t.Error("a2 (which should be 1) plus 2 does not equal 3; value:", a2)
 	}
-
-	x, found = tc.Get("b")
-	if !found {
-		t.Error("b was not found while getting b2")
-	}
-	if x == nil {
-		t.Error("x for b is nil")
-	} else if b2 := x.(string); b2+"B" != "bB" {
-		t.Error("b2 (which should be b) plus B does not equal bB; value:", b2)
-	}
-
-	x, found = tc.Get("c")
-	if !found {
-		t.Error("c was not found while getting c2")
-	}
-	if x == nil {
-		t.Error("x for c is nil")
-	} else if c2 := x.(float64); c2+1.2 != 4.7 {
-		t.Error("c2 (which should be 3.5) plus 1.2 does not equal 4.7; value:", c2)
-	}
 }
 
 func TestCacheTimes(t *testing.T) {
-	var found bool
+	var x *ValueType
 
 	tc := New(50*time.Millisecond, 1*time.Millisecond)
 	tc.Set("a", 1, DefaultExpiration)
@@ -78,1047 +51,45 @@ func TestCacheTimes(t *testing.T) {
 	tc.Set("d", 4, 70*time.Millisecond)
 
 	<-time.After(25 * time.Millisecond)
-	_, found = tc.Get("c")
-	if found {
-		t.Error("Found c when it should have been automatically deleted")
+	x = tc.Get("c")
+	if x != nil {
+		t.Error("Found c when it should have been automatically deleted", *x)
 	}
 
 	<-time.After(30 * time.Millisecond)
-	_, found = tc.Get("a")
-	if found {
-		t.Error("Found a when it should have been automatically deleted")
+	x = tc.Get("a")
+	if x != nil {
+		t.Error("Found a when it should have been automatically deleted", *x)
 	}
 
-	_, found = tc.Get("b")
-	if !found {
+	x = tc.Get("b")
+	if x == nil {
 		t.Error("Did not find b even though it was set to never expire")
 	}
 
-	_, found = tc.Get("d")
-	if !found {
+	x = tc.Get("d")
+	if x == nil {
 		t.Error("Did not find d even though it was set to expire later than the default")
 	}
 
 	<-time.After(20 * time.Millisecond)
-	_, found = tc.Get("d")
-	if found {
+	x = tc.Get("d")
+	if x != nil {
 		t.Error("Found d when it should have been automatically deleted (later than the default)")
 	}
 }
 
-func TestNewFrom(t *testing.T) {
-	m := map[string]Item{
-		"a": Item{
-			Object:     1,
-			Expiration: 0,
-		},
-		"b": Item{
-			Object:     2,
-			Expiration: 0,
-		},
-	}
-	tc := NewFrom(DefaultExpiration, 0, m)
-	a, found := tc.Get("a")
-	if !found {
-		t.Fatal("Did not find a")
-	}
-	if a.(int) != 1 {
-		t.Fatal("a is not 1")
-	}
-	b, found := tc.Get("b")
-	if !found {
-		t.Fatal("Did not find b")
-	}
-	if b.(int) != 2 {
-		t.Fatal("b is not 2")
-	}
-}
-
-func TestStorePointerToStruct(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("foo", &TestStruct{Num: 1}, DefaultExpiration)
-	x, found := tc.Get("foo")
-	if !found {
-		t.Fatal("*TestStruct was not found for foo")
-	}
-	foo := x.(*TestStruct)
-	foo.Num++
-
-	y, found := tc.Get("foo")
-	if !found {
-		t.Fatal("*TestStruct was not found for foo (second time)")
-	}
-	bar := y.(*TestStruct)
-	if bar.Num != 2 {
-		t.Fatal("TestStruct.Num is not 2")
-	}
-}
-
+// TODO: test increment.
 func TestIncrementWithInt(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint", 1, DefaultExpiration)
-	err := tc.Increment("tint", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tint")
-	if !found {
-		t.Error("tint was not found")
-	}
-	if x.(int) != 3 {
-		t.Error("tint is not 3:", x)
-	}
-}
-
-func TestIncrementWithInt8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint8", int8(1), DefaultExpiration)
-	err := tc.Increment("tint8", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tint8")
-	if !found {
-		t.Error("tint8 was not found")
-	}
-	if x.(int8) != 3 {
-		t.Error("tint8 is not 3:", x)
-	}
-}
-
-func TestIncrementWithInt16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint16", int16(1), DefaultExpiration)
-	err := tc.Increment("tint16", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tint16")
-	if !found {
-		t.Error("tint16 was not found")
-	}
-	if x.(int16) != 3 {
-		t.Error("tint16 is not 3:", x)
-	}
-}
-
-func TestIncrementWithInt32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint32", int32(1), DefaultExpiration)
-	err := tc.Increment("tint32", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tint32")
-	if !found {
-		t.Error("tint32 was not found")
-	}
-	if x.(int32) != 3 {
-		t.Error("tint32 is not 3:", x)
-	}
-}
-
-func TestIncrementWithInt64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint64", int64(1), DefaultExpiration)
-	err := tc.Increment("tint64", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tint64")
-	if !found {
-		t.Error("tint64 was not found")
-	}
-	if x.(int64) != 3 {
-		t.Error("tint64 is not 3:", x)
-	}
-}
-
-func TestIncrementWithUint(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint", uint(1), DefaultExpiration)
-	err := tc.Increment("tuint", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tuint")
-	if !found {
-		t.Error("tuint was not found")
-	}
-	if x.(uint) != 3 {
-		t.Error("tuint is not 3:", x)
-	}
-}
-
-func TestIncrementWithUintptr(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuintptr", uintptr(1), DefaultExpiration)
-	err := tc.Increment("tuintptr", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-
-	x, found := tc.Get("tuintptr")
-	if !found {
-		t.Error("tuintptr was not found")
-	}
-	if x.(uintptr) != 3 {
-		t.Error("tuintptr is not 3:", x)
-	}
-}
-
-func TestIncrementWithUint8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint8", uint8(1), DefaultExpiration)
-	err := tc.Increment("tuint8", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tuint8")
-	if !found {
-		t.Error("tuint8 was not found")
-	}
-	if x.(uint8) != 3 {
-		t.Error("tuint8 is not 3:", x)
-	}
-}
-
-func TestIncrementWithUint16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint16", uint16(1), DefaultExpiration)
-	err := tc.Increment("tuint16", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-
-	x, found := tc.Get("tuint16")
-	if !found {
-		t.Error("tuint16 was not found")
-	}
-	if x.(uint16) != 3 {
-		t.Error("tuint16 is not 3:", x)
-	}
-}
-
-func TestIncrementWithUint32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint32", uint32(1), DefaultExpiration)
-	err := tc.Increment("tuint32", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("tuint32")
-	if !found {
-		t.Error("tuint32 was not found")
-	}
-	if x.(uint32) != 3 {
-		t.Error("tuint32 is not 3:", x)
-	}
-}
-
-func TestIncrementWithUint64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint64", uint64(1), DefaultExpiration)
-	err := tc.Increment("tuint64", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-
-	x, found := tc.Get("tuint64")
-	if !found {
-		t.Error("tuint64 was not found")
-	}
-	if x.(uint64) != 3 {
-		t.Error("tuint64 is not 3:", x)
-	}
-}
-
-func TestIncrementWithFloat32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float32", float32(1.5), DefaultExpiration)
-	err := tc.Increment("float32", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("float32")
-	if !found {
-		t.Error("float32 was not found")
-	}
-	if x.(float32) != 3.5 {
-		t.Error("float32 is not 3.5:", x)
-	}
-}
-
-func TestIncrementWithFloat64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float64", float64(1.5), DefaultExpiration)
-	err := tc.Increment("float64", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	x, found := tc.Get("float64")
-	if !found {
-		t.Error("float64 was not found")
-	}
-	if x.(float64) != 3.5 {
-		t.Error("float64 is not 3.5:", x)
-	}
-}
-
-func TestIncrementFloatWithFloat32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float32", float32(1.5), DefaultExpiration)
-	err := tc.IncrementFloat("float32", 2)
-	if err != nil {
-		t.Error("Error incrementfloating:", err)
-	}
-	x, found := tc.Get("float32")
-	if !found {
-		t.Error("float32 was not found")
-	}
-	if x.(float32) != 3.5 {
-		t.Error("float32 is not 3.5:", x)
-	}
-}
-
-func TestIncrementFloatWithFloat64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float64", float64(1.5), DefaultExpiration)
-	err := tc.IncrementFloat("float64", 2)
-	if err != nil {
-		t.Error("Error incrementfloating:", err)
-	}
-	x, found := tc.Get("float64")
-	if !found {
-		t.Error("float64 was not found")
-	}
-	if x.(float64) != 3.5 {
-		t.Error("float64 is not 3.5:", x)
-	}
-}
-
-func TestDecrementWithInt(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int", int(5), DefaultExpiration)
-	err := tc.Decrement("int", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("int")
-	if !found {
-		t.Error("int was not found")
-	}
-	if x.(int) != 3 {
-		t.Error("int is not 3:", x)
-	}
-}
-
-func TestDecrementWithInt8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int8", int8(5), DefaultExpiration)
-	err := tc.Decrement("int8", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("int8")
-	if !found {
-		t.Error("int8 was not found")
-	}
-	if x.(int8) != 3 {
-		t.Error("int8 is not 3:", x)
-	}
-}
-
-func TestDecrementWithInt16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int16", int16(5), DefaultExpiration)
-	err := tc.Decrement("int16", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("int16")
-	if !found {
-		t.Error("int16 was not found")
-	}
-	if x.(int16) != 3 {
-		t.Error("int16 is not 3:", x)
-	}
-}
-
-func TestDecrementWithInt32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int32", int32(5), DefaultExpiration)
-	err := tc.Decrement("int32", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("int32")
-	if !found {
-		t.Error("int32 was not found")
-	}
-	if x.(int32) != 3 {
-		t.Error("int32 is not 3:", x)
-	}
-}
-
-func TestDecrementWithInt64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int64", int64(5), DefaultExpiration)
-	err := tc.Decrement("int64", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("int64")
-	if !found {
-		t.Error("int64 was not found")
-	}
-	if x.(int64) != 3 {
-		t.Error("int64 is not 3:", x)
-	}
-}
-
-func TestDecrementWithUint(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint", uint(5), DefaultExpiration)
-	err := tc.Decrement("uint", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("uint")
-	if !found {
-		t.Error("uint was not found")
-	}
-	if x.(uint) != 3 {
-		t.Error("uint is not 3:", x)
-	}
-}
-
-func TestDecrementWithUintptr(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uintptr", uintptr(5), DefaultExpiration)
-	err := tc.Decrement("uintptr", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("uintptr")
-	if !found {
-		t.Error("uintptr was not found")
-	}
-	if x.(uintptr) != 3 {
-		t.Error("uintptr is not 3:", x)
-	}
-}
-
-func TestDecrementWithUint8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint8", uint8(5), DefaultExpiration)
-	err := tc.Decrement("uint8", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("uint8")
-	if !found {
-		t.Error("uint8 was not found")
-	}
-	if x.(uint8) != 3 {
-		t.Error("uint8 is not 3:", x)
-	}
-}
-
-func TestDecrementWithUint16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint16", uint16(5), DefaultExpiration)
-	err := tc.Decrement("uint16", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("uint16")
-	if !found {
-		t.Error("uint16 was not found")
-	}
-	if x.(uint16) != 3 {
-		t.Error("uint16 is not 3:", x)
-	}
-}
-
-func TestDecrementWithUint32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint32", uint32(5), DefaultExpiration)
-	err := tc.Decrement("uint32", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("uint32")
-	if !found {
-		t.Error("uint32 was not found")
-	}
-	if x.(uint32) != 3 {
-		t.Error("uint32 is not 3:", x)
-	}
-}
-
-func TestDecrementWithUint64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint64", uint64(5), DefaultExpiration)
-	err := tc.Decrement("uint64", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("uint64")
-	if !found {
-		t.Error("uint64 was not found")
-	}
-	if x.(uint64) != 3 {
-		t.Error("uint64 is not 3:", x)
-	}
-}
-
-func TestDecrementWithFloat32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float32", float32(5.5), DefaultExpiration)
-	err := tc.Decrement("float32", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("float32")
-	if !found {
-		t.Error("float32 was not found")
-	}
-	if x.(float32) != 3.5 {
-		t.Error("float32 is not 3:", x)
-	}
-}
-
-func TestDecrementWithFloat64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float64", float64(5.5), DefaultExpiration)
-	err := tc.Decrement("float64", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("float64")
-	if !found {
-		t.Error("float64 was not found")
-	}
-	if x.(float64) != 3.5 {
-		t.Error("float64 is not 3:", x)
-	}
-}
-
-func TestDecrementFloatWithFloat32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float32", float32(5.5), DefaultExpiration)
-	err := tc.DecrementFloat("float32", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("float32")
-	if !found {
-		t.Error("float32 was not found")
-	}
-	if x.(float32) != 3.5 {
-		t.Error("float32 is not 3:", x)
-	}
-}
-
-func TestDecrementFloatWithFloat64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float64", float64(5.5), DefaultExpiration)
-	err := tc.DecrementFloat("float64", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	x, found := tc.Get("float64")
-	if !found {
-		t.Error("float64 was not found")
-	}
-	if x.(float64) != 3.5 {
-		t.Error("float64 is not 3:", x)
-	}
-}
-
-func TestIncrementInt(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint", 1, DefaultExpiration)
-	n, err := tc.IncrementInt("tint", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tint")
-	if !found {
-		t.Error("tint was not found")
-	}
-	if x.(int) != 3 {
-		t.Error("tint is not 3:", x)
-	}
-}
-
-func TestIncrementInt8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint8", int8(1), DefaultExpiration)
-	n, err := tc.IncrementInt8("tint8", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tint8")
-	if !found {
-		t.Error("tint8 was not found")
-	}
-	if x.(int8) != 3 {
-		t.Error("tint8 is not 3:", x)
-	}
-}
-
-func TestIncrementInt16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint16", int16(1), DefaultExpiration)
-	n, err := tc.IncrementInt16("tint16", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tint16")
-	if !found {
-		t.Error("tint16 was not found")
-	}
-	if x.(int16) != 3 {
-		t.Error("tint16 is not 3:", x)
-	}
-}
-
-func TestIncrementInt32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint32", int32(1), DefaultExpiration)
-	n, err := tc.IncrementInt32("tint32", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tint32")
-	if !found {
-		t.Error("tint32 was not found")
-	}
-	if x.(int32) != 3 {
-		t.Error("tint32 is not 3:", x)
-	}
-}
-
-func TestIncrementInt64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tint64", int64(1), DefaultExpiration)
-	n, err := tc.IncrementInt64("tint64", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tint64")
-	if !found {
-		t.Error("tint64 was not found")
-	}
-	if x.(int64) != 3 {
-		t.Error("tint64 is not 3:", x)
-	}
-}
-
-func TestIncrementUint(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint", uint(1), DefaultExpiration)
-	n, err := tc.IncrementUint("tuint", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tuint")
-	if !found {
-		t.Error("tuint was not found")
-	}
-	if x.(uint) != 3 {
-		t.Error("tuint is not 3:", x)
-	}
-}
-
-func TestIncrementUintptr(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuintptr", uintptr(1), DefaultExpiration)
-	n, err := tc.IncrementUintptr("tuintptr", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tuintptr")
-	if !found {
-		t.Error("tuintptr was not found")
-	}
-	if x.(uintptr) != 3 {
-		t.Error("tuintptr is not 3:", x)
-	}
-}
-
-func TestIncrementUint8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint8", uint8(1), DefaultExpiration)
-	n, err := tc.IncrementUint8("tuint8", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tuint8")
-	if !found {
-		t.Error("tuint8 was not found")
-	}
-	if x.(uint8) != 3 {
-		t.Error("tuint8 is not 3:", x)
-	}
-}
-
-func TestIncrementUint16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint16", uint16(1), DefaultExpiration)
-	n, err := tc.IncrementUint16("tuint16", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tuint16")
-	if !found {
-		t.Error("tuint16 was not found")
-	}
-	if x.(uint16) != 3 {
-		t.Error("tuint16 is not 3:", x)
-	}
-}
-
-func TestIncrementUint32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint32", uint32(1), DefaultExpiration)
-	n, err := tc.IncrementUint32("tuint32", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tuint32")
-	if !found {
-		t.Error("tuint32 was not found")
-	}
-	if x.(uint32) != 3 {
-		t.Error("tuint32 is not 3:", x)
-	}
-}
-
-func TestIncrementUint64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("tuint64", uint64(1), DefaultExpiration)
-	n, err := tc.IncrementUint64("tuint64", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("tuint64")
-	if !found {
-		t.Error("tuint64 was not found")
-	}
-	if x.(uint64) != 3 {
-		t.Error("tuint64 is not 3:", x)
-	}
-}
-
-func TestIncrementFloat32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float32", float32(1.5), DefaultExpiration)
-	n, err := tc.IncrementFloat32("float32", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3.5 {
-		t.Error("Returned number is not 3.5:", n)
-	}
-	x, found := tc.Get("float32")
-	if !found {
-		t.Error("float32 was not found")
-	}
-	if x.(float32) != 3.5 {
-		t.Error("float32 is not 3.5:", x)
-	}
-}
-
-func TestIncrementFloat64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float64", float64(1.5), DefaultExpiration)
-	n, err := tc.IncrementFloat64("float64", 2)
-	if err != nil {
-		t.Error("Error incrementing:", err)
-	}
-	if n != 3.5 {
-		t.Error("Returned number is not 3.5:", n)
-	}
-	x, found := tc.Get("float64")
-	if !found {
-		t.Error("float64 was not found")
-	}
-	if x.(float64) != 3.5 {
-		t.Error("float64 is not 3.5:", x)
-	}
-}
-
-func TestDecrementInt8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int8", int8(5), DefaultExpiration)
-	n, err := tc.DecrementInt8("int8", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("int8")
-	if !found {
-		t.Error("int8 was not found")
-	}
-	if x.(int8) != 3 {
-		t.Error("int8 is not 3:", x)
-	}
-}
-
-func TestDecrementInt16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int16", int16(5), DefaultExpiration)
-	n, err := tc.DecrementInt16("int16", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("int16")
-	if !found {
-		t.Error("int16 was not found")
-	}
-	if x.(int16) != 3 {
-		t.Error("int16 is not 3:", x)
-	}
-}
-
-func TestDecrementInt32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int32", int32(5), DefaultExpiration)
-	n, err := tc.DecrementInt32("int32", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("int32")
-	if !found {
-		t.Error("int32 was not found")
-	}
-	if x.(int32) != 3 {
-		t.Error("int32 is not 3:", x)
-	}
-}
-
-func TestDecrementInt64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int64", int64(5), DefaultExpiration)
-	n, err := tc.DecrementInt64("int64", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("int64")
-	if !found {
-		t.Error("int64 was not found")
-	}
-	if x.(int64) != 3 {
-		t.Error("int64 is not 3:", x)
-	}
-}
-
-func TestDecrementUint(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint", uint(5), DefaultExpiration)
-	n, err := tc.DecrementUint("uint", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("uint")
-	if !found {
-		t.Error("uint was not found")
-	}
-	if x.(uint) != 3 {
-		t.Error("uint is not 3:", x)
-	}
-}
-
-func TestDecrementUintptr(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uintptr", uintptr(5), DefaultExpiration)
-	n, err := tc.DecrementUintptr("uintptr", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("uintptr")
-	if !found {
-		t.Error("uintptr was not found")
-	}
-	if x.(uintptr) != 3 {
-		t.Error("uintptr is not 3:", x)
-	}
-}
-
-func TestDecrementUint8(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint8", uint8(5), DefaultExpiration)
-	n, err := tc.DecrementUint8("uint8", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("uint8")
-	if !found {
-		t.Error("uint8 was not found")
-	}
-	if x.(uint8) != 3 {
-		t.Error("uint8 is not 3:", x)
-	}
-}
-
-func TestDecrementUint16(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint16", uint16(5), DefaultExpiration)
-	n, err := tc.DecrementUint16("uint16", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("uint16")
-	if !found {
-		t.Error("uint16 was not found")
-	}
-	if x.(uint16) != 3 {
-		t.Error("uint16 is not 3:", x)
-	}
-}
-
-func TestDecrementUint32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint32", uint32(5), DefaultExpiration)
-	n, err := tc.DecrementUint32("uint32", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("uint32")
-	if !found {
-		t.Error("uint32 was not found")
-	}
-	if x.(uint32) != 3 {
-		t.Error("uint32 is not 3:", x)
-	}
-}
-
-func TestDecrementUint64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint64", uint64(5), DefaultExpiration)
-	n, err := tc.DecrementUint64("uint64", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("uint64")
-	if !found {
-		t.Error("uint64 was not found")
-	}
-	if x.(uint64) != 3 {
-		t.Error("uint64 is not 3:", x)
-	}
-}
-
-func TestDecrementFloat32(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float32", float32(5), DefaultExpiration)
-	n, err := tc.DecrementFloat32("float32", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("float32")
-	if !found {
-		t.Error("float32 was not found")
-	}
-	if x.(float32) != 3 {
-		t.Error("float32 is not 3:", x)
-	}
-}
-
-func TestDecrementFloat64(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("float64", float64(5), DefaultExpiration)
-	n, err := tc.DecrementFloat64("float64", 2)
-	if err != nil {
-		t.Error("Error decrementing:", err)
-	}
-	if n != 3 {
-		t.Error("Returned number is not 3:", n)
-	}
-	x, found := tc.Get("float64")
-	if !found {
-		t.Error("float64 was not found")
-	}
-	if x.(float64) != 3 {
-		t.Error("float64 is not 3:", x)
-	}
 }
 
 func TestAdd(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
-	err := tc.Add("foo", "bar", DefaultExpiration)
+	err := tc.Add("foo", 1, DefaultExpiration)
 	if err != nil {
 		t.Error("Couldn't add foo even though it shouldn't exist")
 	}
-	err = tc.Add("foo", "baz", DefaultExpiration)
+	err = tc.Add("foo", 2, DefaultExpiration)
 	if err == nil {
 		t.Error("Successfully added another foo when it should have returned an error")
 	}
@@ -1126,12 +97,12 @@ func TestAdd(t *testing.T) {
 
 func TestReplace(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
-	err := tc.Replace("foo", "bar", DefaultExpiration)
+	err := tc.Replace("foo", 1, DefaultExpiration)
 	if err == nil {
 		t.Error("Replaced foo when it shouldn't exist")
 	}
-	tc.Set("foo", "bar", DefaultExpiration)
-	err = tc.Replace("foo", "bar", DefaultExpiration)
+	tc.Set("foo", 1, DefaultExpiration)
+	err = tc.Replace("foo", 2, DefaultExpiration)
 	if err != nil {
 		t.Error("Couldn't replace existing key foo")
 	}
@@ -1139,12 +110,9 @@ func TestReplace(t *testing.T) {
 
 func TestDelete(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
-	tc.Set("foo", "bar", DefaultExpiration)
+	tc.Set("foo", 1, DefaultExpiration)
 	tc.Delete("foo")
-	x, found := tc.Get("foo")
-	if found {
-		t.Error("foo was found, but it should have been deleted")
-	}
+	x := tc.Get("foo")
 	if x != nil {
 		t.Error("x is not nil:", x)
 	}
@@ -1152,9 +120,9 @@ func TestDelete(t *testing.T) {
 
 func TestItemCount(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
-	tc.Set("foo", "1", DefaultExpiration)
-	tc.Set("bar", "2", DefaultExpiration)
-	tc.Set("baz", "3", DefaultExpiration)
+	tc.Set("foo", 1, DefaultExpiration)
+	tc.Set("bar", 2, DefaultExpiration)
+	tc.Set("baz", 3, DefaultExpiration)
 	if n := tc.ItemCount(); n != 3 {
 		t.Errorf("Item count is not 3: %d", n)
 	}
@@ -1162,269 +130,42 @@ func TestItemCount(t *testing.T) {
 
 func TestFlush(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
-	tc.Set("foo", "bar", DefaultExpiration)
-	tc.Set("baz", "yes", DefaultExpiration)
+	tc.Set("foo", 1, DefaultExpiration)
+	tc.Set("baz", 2, DefaultExpiration)
 	tc.Flush()
-	x, found := tc.Get("foo")
-	if found {
-		t.Error("foo was found, but it should have been deleted")
-	}
+	x := tc.Get("foo")
 	if x != nil {
 		t.Error("x is not nil:", x)
 	}
-	x, found = tc.Get("baz")
-	if found {
-		t.Error("baz was found, but it should have been deleted")
-	}
+	x = tc.Get("baz")
 	if x != nil {
 		t.Error("x is not nil:", x)
 	}
 }
 
-func TestIncrementOverflowInt(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("int8", int8(127), DefaultExpiration)
-	err := tc.Increment("int8", 1)
-	if err != nil {
-		t.Error("Error incrementing int8:", err)
-	}
-	x, _ := tc.Get("int8")
-	int8 := x.(int8)
-	if int8 != -128 {
-		t.Error("int8 did not overflow as expected; value:", int8)
-	}
-
-}
-
-func TestIncrementOverflowUint(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint8", uint8(255), DefaultExpiration)
-	err := tc.Increment("uint8", 1)
-	if err != nil {
-		t.Error("Error incrementing int8:", err)
-	}
-	x, _ := tc.Get("uint8")
-	uint8 := x.(uint8)
-	if uint8 != 0 {
-		t.Error("uint8 did not overflow as expected; value:", uint8)
-	}
-}
-
-func TestDecrementUnderflowUint(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Set("uint8", uint8(0), DefaultExpiration)
-	err := tc.Decrement("uint8", 1)
-	if err != nil {
-		t.Error("Error decrementing int8:", err)
-	}
-	x, _ := tc.Get("uint8")
-	uint8 := x.(uint8)
-	if uint8 != 255 {
-		t.Error("uint8 did not underflow as expected; value:", uint8)
-	}
-}
-
 func TestOnEvicted(t *testing.T) {
 	tc := New(DefaultExpiration, 0)
-	tc.Set("foo", 3, DefaultExpiration)
+	tc.Set("foo", ValueType(3), DefaultExpiration)
 	if tc.onEvicted != nil {
 		t.Fatal("tc.onEvicted is not nil")
 	}
 	works := false
-	tc.OnEvicted(func(k string, v interface{}) {
-		if k == "foo" && v.(int) == 3 {
+	tc.OnEvicted(func(k string, v *ValueType) {
+		if k == "foo" && int(*v) == 3 {
 			works = true
 		}
-		tc.Set("bar", 4, DefaultExpiration)
+		tc.Set("bar", ValueType(4), DefaultExpiration)
 	})
 	tc.Delete("foo")
-	x, _ := tc.Get("bar")
+	x := tc.Get("bar")
 	if !works {
 		t.Error("works bool not true")
 	}
-	if x.(int) != 4 {
+	if int(*x) != 4 {
 		t.Error("bar was not 4")
 	}
 }
 
-func TestCacheSerialization(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	testFillAndSerialize(t, tc)
-
-	// Check if gob.Register behaves properly even after multiple gob.Register
-	// on c.Items (many of which will be the same type)
-	testFillAndSerialize(t, tc)
-}
-
-func testFillAndSerialize(t *testing.T, tc *Cache) {
-	tc.Set("a", "a", DefaultExpiration)
-	tc.Set("b", "b", DefaultExpiration)
-	tc.Set("c", "c", DefaultExpiration)
-	tc.Set("expired", "foo", 1*time.Millisecond)
-	tc.Set("*struct", &TestStruct{Num: 1}, DefaultExpiration)
-	tc.Set("[]struct", []TestStruct{
-		{Num: 2},
-		{Num: 3},
-	}, DefaultExpiration)
-	tc.Set("[]*struct", []*TestStruct{
-		&TestStruct{Num: 4},
-		&TestStruct{Num: 5},
-	}, DefaultExpiration)
-	tc.Set("structception", &TestStruct{
-		Num: 42,
-		Children: []*TestStruct{
-			&TestStruct{Num: 6174},
-			&TestStruct{Num: 4716},
-		},
-	}, DefaultExpiration)
-
-	fp := &bytes.Buffer{}
-	err := tc.Save(fp)
-	if err != nil {
-		t.Fatal("Couldn't save cache to fp:", err)
-	}
-
-	oc := New(DefaultExpiration, 0)
-	err = oc.Load(fp)
-	if err != nil {
-		t.Fatal("Couldn't load cache from fp:", err)
-	}
-
-	a, found := oc.Get("a")
-	if !found {
-		t.Error("a was not found")
-	}
-	if a.(string) != "a" {
-		t.Error("a is not a")
-	}
-
-	b, found := oc.Get("b")
-	if !found {
-		t.Error("b was not found")
-	}
-	if b.(string) != "b" {
-		t.Error("b is not b")
-	}
-
-	c, found := oc.Get("c")
-	if !found {
-		t.Error("c was not found")
-	}
-	if c.(string) != "c" {
-		t.Error("c is not c")
-	}
-
-	<-time.After(5 * time.Millisecond)
-	_, found = oc.Get("expired")
-	if found {
-		t.Error("expired was found")
-	}
-
-	s1, found := oc.Get("*struct")
-	if !found {
-		t.Error("*struct was not found")
-	}
-	if s1.(*TestStruct).Num != 1 {
-		t.Error("*struct.Num is not 1")
-	}
-
-	s2, found := oc.Get("[]struct")
-	if !found {
-		t.Error("[]struct was not found")
-	}
-	s2r := s2.([]TestStruct)
-	if len(s2r) != 2 {
-		t.Error("Length of s2r is not 2")
-	}
-	if s2r[0].Num != 2 {
-		t.Error("s2r[0].Num is not 2")
-	}
-	if s2r[1].Num != 3 {
-		t.Error("s2r[1].Num is not 3")
-	}
-
-	s3, found := oc.get("[]*struct")
-	if !found {
-		t.Error("[]*struct was not found")
-	}
-	s3r := s3.([]*TestStruct)
-	if len(s3r) != 2 {
-		t.Error("Length of s3r is not 2")
-	}
-	if s3r[0].Num != 4 {
-		t.Error("s3r[0].Num is not 4")
-	}
-	if s3r[1].Num != 5 {
-		t.Error("s3r[1].Num is not 5")
-	}
-
-	s4, found := oc.get("structception")
-	if !found {
-		t.Error("structception was not found")
-	}
-	s4r := s4.(*TestStruct)
-	if len(s4r.Children) != 2 {
-		t.Error("Length of s4r.Children is not 2")
-	}
-	if s4r.Children[0].Num != 6174 {
-		t.Error("s4r.Children[0].Num is not 6174")
-	}
-	if s4r.Children[1].Num != 4716 {
-		t.Error("s4r.Children[1].Num is not 4716")
-	}
-}
-
-func TestFileSerialization(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	tc.Add("a", "a", DefaultExpiration)
-	tc.Add("b", "b", DefaultExpiration)
-	f, err := ioutil.TempFile("", "go-cache-cache.dat")
-	if err != nil {
-		t.Fatal("Couldn't create cache file:", err)
-	}
-	fname := f.Name()
-	f.Close()
-	tc.SaveFile(fname)
-
-	oc := New(DefaultExpiration, 0)
-	oc.Add("a", "aa", 0) // this should not be overwritten
-	err = oc.LoadFile(fname)
-	if err != nil {
-		t.Error(err)
-	}
-	a, found := oc.Get("a")
-	if !found {
-		t.Error("a was not found")
-	}
-	astr := a.(string)
-	if astr != "aa" {
-		if astr == "a" {
-			t.Error("a was overwritten")
-		} else {
-			t.Error("a is not aa")
-		}
-	}
-	b, found := oc.Get("b")
-	if !found {
-		t.Error("b was not found")
-	}
-	if b.(string) != "b" {
-		t.Error("b is not b")
-	}
-}
-
-func TestSerializeUnserializable(t *testing.T) {
-	tc := New(DefaultExpiration, 0)
-	ch := make(chan bool, 1)
-	ch <- true
-	tc.Set("chan", ch, DefaultExpiration)
-	fp := &bytes.Buffer{}
-	err := tc.Save(fp) // this should fail gracefully
-	if err.Error() != "gob NewTypeObject can't handle type: chan bool" {
-		t.Error("Error from Save was not gob NewTypeObject can't handle type chan bool:", err)
-	}
-}
-
 func BenchmarkCacheGetExpiring(b *testing.B) {
 	benchmarkCacheGet(b, 5*time.Minute)
 }
@@ -1436,7 +177,7 @@ func BenchmarkCacheGetNotExpiring(b *testing.B) {
 func benchmarkCacheGet(b *testing.B, exp time.Duration) {
 	b.StopTimer()
 	tc := New(exp, 0)
-	tc.Set("foo", "bar", DefaultExpiration)
+	tc.Set("foo", 1, DefaultExpiration)
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		tc.Get("foo")
@@ -1459,7 +200,7 @@ func BenchmarkRWMutexMapGet(b *testing.B) {
 
 func BenchmarkRWMutexInterfaceMapGetStruct(b *testing.B) {
 	b.StopTimer()
-	s := struct{name string}{name: "foo"}
+	s := struct{ name string }{name: "foo"}
 	m := map[interface{}]string{
 		s: "bar",
 	}
@@ -1497,7 +238,7 @@ func BenchmarkCacheGetConcurrentNotExpiring(b *testing.B) {
 func benchmarkCacheGetConcurrent(b *testing.B, exp time.Duration) {
 	b.StopTimer()
 	tc := New(exp, 0)
-	tc.Set("foo", "bar", DefaultExpiration)
+	tc.Set("foo", 1, DefaultExpiration)
 	wg := new(sync.WaitGroup)
 	workers := runtime.NumCPU()
 	each := b.N / workers
@@ -1555,9 +296,9 @@ func benchmarkCacheGetManyConcurrent(b *testing.B, exp time.Duration) {
 	tc := New(exp, 0)
 	keys := make([]string, n)
 	for i := 0; i < n; i++ {
-		k := "foo" + strconv.Itoa(n)
+		k := "foo" + strconv.Itoa(i)
 		keys[i] = k
-		tc.Set(k, "bar", DefaultExpiration)
+		tc.Set(k, ValueType(1), DefaultExpiration)
 	}
 	each := b.N / n
 	wg := new(sync.WaitGroup)
@@ -1587,7 +328,7 @@ func benchmarkCacheSet(b *testing.B, exp time.Duration) {
 	tc := New(exp, 0)
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
-		tc.Set("foo", "bar", DefaultExpiration)
+		tc.Set("foo", 1, DefaultExpiration)
 	}
 }
 
@@ -1608,7 +349,7 @@ func BenchmarkCacheSetDelete(b *testing.B) {
 	tc := New(DefaultExpiration, 0)
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
-		tc.Set("foo", "bar", DefaultExpiration)
+		tc.Set("foo", 1, DefaultExpiration)
 		tc.Delete("foo")
 	}
 }
@@ -1634,7 +375,7 @@ func BenchmarkCacheSetDeleteSingleLock(b *testing.B) {
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		tc.mu.Lock()
-		tc.set("foo", "bar", DefaultExpiration)
+		tc.set("foo", 1, DefaultExpiration)
 		tc.delete("foo")
 		tc.mu.Unlock()
 	}
@@ -1654,12 +395,13 @@ func BenchmarkRWMutexMapSetDeleteSingleLock(b *testing.B) {
 }
 
 func BenchmarkIncrementInt(b *testing.B) {
+	b.Skip()
 	b.StopTimer()
 	tc := New(DefaultExpiration, 0)
 	tc.Set("foo", 0, DefaultExpiration)
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
-		tc.IncrementInt("foo", 1)
+		// tc.IncrementInt("foo", 1)
 	}
 }
 
@@ -1668,7 +410,7 @@ func BenchmarkDeleteExpiredLoop(b *testing.B) {
 	tc := New(5*time.Minute, 0)
 	tc.mu.Lock()
 	for i := 0; i < 100000; i++ {
-		tc.set(strconv.Itoa(i), "bar", DefaultExpiration)
+		tc.set(strconv.Itoa(i), 1, DefaultExpiration)
 	}
 	tc.mu.Unlock()
 	b.StartTimer()
diff --git a/sharded.go b/sharded.go
index bcc0538..b1ab771 100644
--- a/sharded.go
+++ b/sharded.go
@@ -66,19 +66,19 @@ func (sc *shardedCache) bucket(k string) *cache {
 	return sc.cs[djb33(sc.seed, k)%sc.m]
 }
 
-func (sc *shardedCache) Set(k string, x interface{}, d time.Duration) {
+func (sc *shardedCache) Set(k string, x ValueType, d time.Duration) {
 	sc.bucket(k).Set(k, x, d)
 }
 
-func (sc *shardedCache) Add(k string, x interface{}, d time.Duration) error {
+func (sc *shardedCache) Add(k string, x ValueType, d time.Duration) error {
 	return sc.bucket(k).Add(k, x, d)
 }
 
-func (sc *shardedCache) Replace(k string, x interface{}, d time.Duration) error {
+func (sc *shardedCache) Replace(k string, x ValueType, d time.Duration) error {
 	return sc.bucket(k).Replace(k, x, d)
 }
 
-func (sc *shardedCache) Get(k string) (interface{}, bool) {
+func (sc *shardedCache) Get(k string) *ValueType {
 	return sc.bucket(k).Get(k)
 }
 
@@ -86,10 +86,6 @@ func (sc *shardedCache) Increment(k string, n int64) error {
 	return sc.bucket(k).Increment(k, n)
 }
 
-func (sc *shardedCache) IncrementFloat(k string, n float64) error {
-	return sc.bucket(k).IncrementFloat(k, n)
-}
-
 func (sc *shardedCache) Decrement(k string, n int64) error {
 	return sc.bucket(k).Decrement(k, n)
 }
@@ -109,12 +105,9 @@ func (sc *shardedCache) DeleteExpired() {
 // fields of the items should be checked. Note that explicit synchronization
 // is needed to use a cache and its corresponding Items() return values at
 // the same time, as the maps are shared.
-func (sc *shardedCache) Items() []map[string]Item {
-	res := make([]map[string]Item, len(sc.cs))
-	for i, v := range sc.cs {
-		res[i] = v.Items()
-	}
-	return res
+// TODO: 不准备暴露这个接口,使用者不应该知道底层的数据.
+func (sc *shardedCache) items() []map[string]Item {
+	return nil
 }
 
 func (sc *shardedCache) Flush() {
diff --git a/sharded_test.go b/sharded_test.go
index aef8597..01e1e11 100644
--- a/sharded_test.go
+++ b/sharded_test.go
@@ -29,7 +29,7 @@ var shardedKeys = []string{
 func TestShardedCache(t *testing.T) {
 	tc := unexportedNewSharded(DefaultExpiration, 0, 13)
 	for _, v := range shardedKeys {
-		tc.Set(v, "value", DefaultExpiration)
+		tc.Set(v, ValueType(1), DefaultExpiration)
 	}
 }
 
@@ -44,7 +44,7 @@ func BenchmarkShardedCacheGetNotExpiring(b *testing.B) {
 func benchmarkShardedCacheGet(b *testing.B, exp time.Duration) {
 	b.StopTimer()
 	tc := unexportedNewSharded(exp, 0, 10)
-	tc.Set("foobarba", "zquux", DefaultExpiration)
+	tc.Set("foobarba", ValueType(1), DefaultExpiration)
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
 		tc.Get("foobarba")
@@ -65,9 +65,9 @@ func benchmarkShardedCacheGetManyConcurrent(b *testing.B, exp time.Duration) {
 	tsc := unexportedNewSharded(exp, 0, 20)
 	keys := make([]string, n)
 	for i := 0; i < n; i++ {
-		k := "foo" + strconv.Itoa(n)
+		k := "foo" + strconv.Itoa(i)
 		keys[i] = k
-		tsc.Set(k, "bar", DefaultExpiration)
+		tsc.Set(k, ValueType(1), DefaultExpiration)
 	}
 	each := b.N / n
 	wg := new(sync.WaitGroup)
diff --git a/valtyp.go b/valtyp.go
new file mode 100644
index 0000000..b31a4d3
--- /dev/null
+++ b/valtyp.go
@@ -0,0 +1,3 @@
+package cache
+
+type ValueType int