What is the difference between a regular expression quoted by ` and "?

Question

Why the C:\\\\ (quoted by `) regexp does not match "C:\\" and "C:\\\\" do ?

r, err := regexp.Compile(`C:\\\\`) // Not match
r, err := regexp.Compile("C:\\\\")  // Matches
if r.MatchString("Working on drive C:\\") == true {
    fmt.Printf("Matches.") 
} else {
    fmt.Printf("No match.")
}

Answer 1

Escape sequences in raw string literal (quoted by quotes) are not interpreted.

`C:\\\\`

is equivalent to:

"C:\\\\\\\\"

See The Go Programming Language Specification - String literals.