proposal: x/tools/cmd/eg: support for generics

[janisz]

Proposal Details

It will be great is eg can support generics in a way it can handle e.g. slices of different types.

Example: Replacing a method that takes slices of elements that implements given interface.

package template

import (
        "github.com/golang/protobuf/proto"
        "github.com/stackrox/rox/pkg/protoassert"
        "github.com/stretchr/testify/assert"
        "testing"
)

func before[T proto.Message](t *testing.T, a, b []T) bool {
        return assert.Equal(t, a, b)
}

func after[T proto.Message](t *testing.T, a, b []T) bool {
        return protoassert.SlicesEqual(t, a, b)
}

[ianlancetaylor]

CC @alandonovan @golang/tools-team