tree 58554278da3eeec38848fcdec7dbb1f99553e7e9
parent 3fe02156777c9eff14a88826cf3aa495b5db3544
author Joe Tsai <joetsai@digital-static.net> 1501102450 -0700
committer Joe Tsai <joetsai@digital-static.net> 1501720663 -0700

Add DiscardElements helper transformer

In some situations users want to compare two maps where missing entries
are equal to those that have the zero value.
For example, the following maps would be considered equal:
	x := map[string]int{"foo": 12345, "zero":0}
	y := map[string]int{"foo": 12345}

To help with this, we add DiscardElements to cmpopts that transforms maps
and slices by stripping entries based on a user provided function.
To strip zero values, the user can provide:
	cmpopts.DiscardElements(func(v int) bool { return v == 0 })