Int64Flag.ValueFromContext() as convenient accessor

flag_int64.go

@@ -101,6 +101,11 @@ func (f *Int64Flag) Apply(set *flag.FlagSet) error {
 	return nil
 }
 
+// ValueFromContext returns the flag’s value in the given Context.
+func (f *Int64Flag) ValueFromContext(ctx *Context) int64 {
+	return ctx.Int64(f.Name)
+}
+
 // Int64 looks up the value of a local Int64Flag, returns
 // 0 if not found
 func (c *Context) Int64(name string) int64 {

flag_test.go

@@ -709,6 +709,14 @@ func TestInt64FlagWithEnvVarHelpOutput(t *testing.T) {
 	}
 }
 
+func TestInt64FlagValueFromContext(t *testing.T) {
+	set := flag.NewFlagSet("test", 0)
+	set.Int64("myflag", 42, "doc")
+	ctx := NewContext(nil, set, nil)
+	f := &Int64Flag{Name: "myflag"}
+	expect(t, f.ValueFromContext(ctx), int64(42))
+}
+
 var uintFlagTests = []struct {
 	name     string
 	expected string