Go: What’s the maximum value of an int?

Go has two predeclared integer types with implementation-specific sizes:

• a uint has either 32 or 64 bits;
• an int has the same size as a uint.

This code computes the limit values as untyped constants:

const BitsPerWord = 32 << (^uint(0) >> 63) // either 32 or 64

const (
        MaxInt  = 1<<(BitsPerWord-1) - 1 // either (1<<31)-1 or (1<<63)-1
        MinInt  = -MaxInt - 1            // either -1<<31 or -1<<63
        MaxUint = 1<<BitsPerWord - 1     // either (1<<32)-1 or (1<<64)-1
)