You can use strings.TrimRightFunc or strings.TrimRightFunc for this:

package main

import (
	"fmt"
	"strings"
	"unicode"
)



func main() {
	fmt.Printf("Trim right spaces: >%s<\n", strings.TrimRightFunc("  你好  ", unicode.IsSpace))
	fmt.Printf("Trim left spaces: >%s<\n", strings.TrimLeftFunc("  你好  ", unicode.IsSpace))
}

https://play.golang.org/p/Kw_dQHQqlKU

If you like, with this, you can easily define TrimLeftSpace and TrimRightSpace yourself.

Thanks for the helpful example, @beoran.

@wannibar I'm going to close this issue, as there is insufficient justification in the original issue to change the standard library, and there is a trivial implementation. Please comment if you disagree, or have more reason as to why we should make this change in Go.