About:

The unconvert program analyzes Go packages to identify unnecessary
type conversions; i.e., expressions T(x) where x already has type T.

Install:

    $ go get github.com/mdempsky/unconvert

Usage:

    $ unconvert bytes
    GOROOT/src/bytes/reader.go:117:14:
                abs = int64(r.i) + offset
                           ^

Flags:

Using the -apply flag, unconvert will rewrite the Go source files
without the unnecessary type conversions.

Using the -all flag, unconvert will analyze the Go packages under all
possible GOOS/GOARCH combinations, and only identify conversions that
are unnecessary in all cases.

E.g., syscall.Timespec's Sec and Nsec fields are int64 under
linux/amd64 but int32 under linux/386.  An int64(ts.Sec) conversion
that appears in a linux/amd64-only file will be identified as
unnecessary, but it will be preserved if it occurs in a file that's
compiled for both linux/amd64 and linux/386.