func (f FlagMap) Float64(long string) float64 {
	i := f[long]
	if i == nil {
		panic(fmt.Errorf("missing flag value: flag '%s' not registered", long))
	}
	v, ok := i.Value.(float64)
	if !ok {
		panic(fmt.Errorf("failed to assert flag '%s' to float64", long))
	}
	return v
}
Float64 returns the given flag value as float64.
Panics if not present. Flags must be registered.
package grumble
import (
	"fmt"
	"time"
)
type FlagMapItem struct {
	Value     interface{}
	IsDefault bool
}
type FlagMap map[string]*FlagMapItem
func (f FlagMap) copyMissingValues(m FlagMap, copyDefault bool) {
	for k, v := range m {
		if _, ok := f[k]; !ok {
			if !copyDefault && v.IsDefault {
				continue
			}
			f[k] = v
		}
	}
}
func (f FlagMap) String(long string) string {
	i := f[long]
	if i == nil {
		panic(fmt.Errorf("missing flag value: flag '%s' not registered", long))
	}
	s, ok := i.Value.(string)
	if !ok {
		panic(fmt.Errorf("failed to assert flag '%s' to string", long))
	}
	return s
}
func (f FlagMap) Bool(long string) bool {
	i := f[long]
	if i == nil {
		panic(fmt.Errorf("missing flag value: flag '%s' not registered", long))
	}
	b, ok := i.Value.(bool)
	if !ok {
		panic(fmt.Errorf("failed to assert flag '%s' to bool", long))
	}
	return b
}
func (f FlagMap) Int(long string) int {
	i := f[long]
	if i == nil {
		panic(fmt.Errorf("missing flag value: flag '%s' not registered", long))
	}
	v, ok := i.Value.(int)
	if !ok {
		panic(fmt.Errorf("failed to assert flag '%s' to int", long))
	}
	return v
}
func (f FlagMap) Int64(long string) int64 {
	i := f[long]
	if i == nil {
		panic(fmt.Errorf("missing flag value: flag '%s' not registered", long))
	}
	v, ok := i.Value.(int64)
	if !ok {
		panic(fmt.Errorf("failed to assert flag '%s' to int64", long))
	}
	return v
}
func (f FlagMap) Uint(long string) uint {
	i := f[long]
	if i == nil {
		panic(fmt.Errorf("missing flag value: flag '%s' not registered", long))
	}
	v, ok := i.Value.(uint)
	if !ok {
		panic(fmt.Errorf("failed to assert flag '%s' to uint", long))
	}
	return v
}
func (f FlagMap) Uint64(long string) uint64 {
	i := f[long]
	if i == nil {
		panic(fmt.Errorf("missing flag value: flag '%s' not registered", long))
	}
	v, ok := i.Value.(uint64)
	if !ok {
		panic(fmt.Errorf("failed to assert flag '%s' to uint64", long))
	}
	return v
}