From 34416a2637176496d7810a6fd59dfbf7fe612796 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Skytt=C3=A4?= <ville.skytta@upcloud.com>
Date: Thu, 5 Oct 2023 23:48:03 +0300
Subject: [PATCH] Preallocate some slices and maps with known size

---
 args.go        | 2 +-
 command.go     | 2 +-
 flag_groups.go | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/args.go b/args.go
index b7674c88..ed1e70ce 100644
--- a/args.go
+++ b/args.go
@@ -52,7 +52,7 @@ func OnlyValidArgs(cmd *Command, args []string) error {
 	if len(cmd.ValidArgs) > 0 {
 		// Remove any description that may be included in ValidArgs.
 		// A description is following a tab character.
-		var validArgs []string
+		validArgs := make([]string, 0, len(cmd.ValidArgs))
 		for _, v := range cmd.ValidArgs {
 			validArgs = append(validArgs, strings.SplitN(v, "\t", 2)[0])
 		}
diff --git a/command.go b/command.go
index 6866f7d0..1764a217 100644
--- a/command.go
+++ b/command.go
@@ -701,7 +701,7 @@ Loop:
 			// This is not a flag or a flag value. Check to see if it matches what we're looking for, and if so,
 			// return the args, excluding the one at this position.
 			if s == x {
-				ret := []string{}
+				ret := make([]string, 0, len(args)-1)
 				ret = append(ret, args[:pos]...)
 				ret = append(ret, args[pos+1:]...)
 				return ret
diff --git a/flag_groups.go b/flag_groups.go
index 0671ec5f..6e938325 100644
--- a/flag_groups.go
+++ b/flag_groups.go
@@ -130,7 +130,7 @@ func processFlagForGroupAnnotation(flags *flag.FlagSet, pflag *flag.Flag, annota
 					continue
 				}
 
-				groupStatus[group] = map[string]bool{}
+				groupStatus[group] = make(map[string]bool, len(flagnames))
 				for _, name := range flagnames {
 					groupStatus[group][name] = false
 				}