utils: switch to standard library min and max functions (#4218)

These functions were added in Go 1.21.

internal/utils/minmax.go

@@ -3,27 +3,11 @@ package utils
 import (
 	"math"
 	"time"
-
-	"golang.org/x/exp/constraints"
 )
 
 // InfDuration is a duration of infinite length
 const InfDuration = time.Duration(math.MaxInt64)
 
-func Max[T constraints.Ordered](a, b T) T {
-	if a < b {
-		return b
-	}
-	return a
-}
-
-func Min[T constraints.Ordered](a, b T) T {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 // MinNonZeroDuration return the minimum duration that's not zero.
 func MinNonZeroDuration(a, b time.Duration) time.Duration {
 	if a == 0 {
@@ -32,7 +16,7 @@ func MinNonZeroDuration(a, b time.Duration) time.Duration {
 	if b == 0 {
 		return a
 	}
-	return Min(a, b)
+	return min(a, b)
 }
 
 // MinTime returns the earlier time

internal/utils/minmax_test.go

@@ -8,16 +8,6 @@ import (
 )
 
 var _ = Describe("Min / Max", func() {
-	It("returns the maximum", func() {
-		Expect(Max(5, 7)).To(Equal(7))
-		Expect(Max(5.5, 5.7)).To(Equal(5.7))
-	})
-
-	It("returns the minimum", func() {
-		Expect(Min(5, 7)).To(Equal(5))
-		Expect(Min(5.5, 5.7)).To(Equal(5.5))
-	})
-
 	It("returns the maximum time", func() {
 		a := time.Now()
 		b := a.Add(time.Second)

internal/utils/rtt_stats.go

@@ -55,7 +55,7 @@ func (r *RTTStats) PTO(includeMaxAckDelay bool) time.Duration {
 	if r.SmoothedRTT() == 0 {
 		return 2 * defaultInitialRTT
 	}
-	pto := r.SmoothedRTT() + Max(4*r.MeanDeviation(), protocol.TimerGranularity)
+	pto := r.SmoothedRTT() + max(4*r.MeanDeviation(), protocol.TimerGranularity)
 	if includeMaxAckDelay {
 		pto += r.MaxAckDelay()
 	}
@@ -126,6 +126,6 @@ func (r *RTTStats) OnConnectionMigration() {
 // is larger. The mean deviation is increased to the most recent deviation if
 // it's larger.
 func (r *RTTStats) ExpireSmoothedMetrics() {
-	r.meanDeviation = Max(r.meanDeviation, (r.smoothedRTT - r.latestRTT).Abs())
-	r.smoothedRTT = Max(r.smoothedRTT, r.latestRTT)
+	r.meanDeviation = max(r.meanDeviation, (r.smoothedRTT - r.latestRTT).Abs())
+	r.smoothedRTT = max(r.smoothedRTT, r.latestRTT)
 }