When will generic specification be supported in Go?

Technical Discussion
2

There is a way to do so without using reflection. But it leads to more expressive handling of possible types, check on playground:

import (
	"fmt"
	"strconv"
	"strings"

	"golang.org/x/exp/constraints"
)

type Number interface {
	constraints.Integer | constraints.Complex | constraints.Float
}

func FormatNumber[T Number](t T, f byte, prec int) (s string) {
	switch v := any(t).(type) {
	case int:
		s = strconv.FormatInt(int64(v), 10)
	case int8:
		s = strconv.FormatInt(int64(v), 10)
	case int16:
		s = strconv.FormatInt(int64(v), 10)
	case int32:
		s = strconv.FormatInt(int64(v), 10)
	case int64:
		s = strconv.FormatInt(v, 10)
	case uint:
		s = strconv.FormatUint(uint64(v), 10)
	case uint8:
		s = strconv.FormatUint(uint64(v), 10)
	case uint16:
		s = strconv.FormatUint(uint64(v), 10)
	case uint32:
		s = strconv.FormatUint(uint64(v), 10)
	case uint64:
		s = strconv.FormatUint(v, 10)
	case float32:
		s = strconv.FormatFloat(float64(v), f, prec, 32)
	case float64:
		s = strconv.FormatFloat(v, f, prec, 64)
	case complex64:
		s = strconv.FormatComplex(complex128(v), f, prec, 64)
	case complex128:
		s = strconv.FormatComplex(v, f, prec, 128)
	default:
		panic("unsupported number type")
	}
	if f >= 'A' && f <= 'Z' {
		s = strings.ToUpper(s)
	}
	return s
}
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