#!/usr/bin/perl

use Benchmark;

sub switchsign
{
  if (substr($_[0],0,1) eq '-')
  {
    substr($_[0],0,1)='+';
  }
  elsif (substr($_[0],0,1) eq '+')
  {
    substr($_[0],0,1)='-';
  }
  else
  {
    substr($_[0],0,0)='-';
  }
}

sub unsign
{
  if (substr($_[0],0,1) eq '-')
  {
    substr($_[0],0,1)='';
  }
  elsif (substr($_[0],0,1) eq '+')
  {
    substr($_[0],0,1)='-';
  }
  else
  {
    substr($_[0],0,0)='-';
  }
}

use constant X => '-'.'99999';

timethese(100_000, {
        switchsign => sub { my $a = X; switchsign($a) },
        unsign => sub { my $a = X; unsign($a) },
        });