Add countable interface

context.go

@@ -105,13 +105,11 @@ func (cCtx *Context) Lineage() []*Context {
 	return lineage
 }
 
-// NumOccurrences returns the num of occurences of this flag
+// Count returns the num of occurences of this flag
 func (cCtx *Context) Count(name string) int {
 	if fs := cCtx.lookupFlagSet(name); fs != nil {
-		if bf, ok := fs.Lookup(name).Value.(*boolValue); ok {
-			if bf.count != nil {
-				return *bf.count
-			}
+		if cf, ok := fs.Lookup(name).Value.(Countable); ok {
+			return cf.Count()
 		}
 	}
 	return 0

flag.go

@@ -124,6 +124,12 @@ type Flag interface {
 	GetValue() string
 }
 
+// Countable is an interface to enable detection of flag values which support
+// repetitive flags
+type Countable interface {
+	Count() int
+}
+
 func flagSet(name string, flags []Flag) (*flag.FlagSet, error) {
 	set := flag.NewFlagSet(name, flag.ContinueOnError)
 

flag_bool.go

@@ -51,6 +51,13 @@ func (b *boolValue) String() string {
 
 func (b *boolValue) IsBoolFlag() bool { return true }
 
+func (b *boolValue) Count() int {
+	if b.count != nil {
+		return *b.count
+	}
+	return 0
+}
+
 // GetValue returns the flags value as string representation and an empty
 // string if the flag takes no value at all.
 func (f *BoolFlag) GetValue() string {