Table of Contents

• func make(t Type, size ...IntegerType) Type
• func copy(dst, src []Type) int

Package builtin provides documentation for Go's predeclared identifiers. The items documented here are not actually in package builtin.

func make(t Type, size ...IntegerType) Type reference

Allocates and initializes an object of type slice, map, or chan (only)

Slice

make([]int, len, cap)
make([]int, len)  // the default cap is equal to len

Map

make(map[string]int)
make(map[string]int, size) // allocated with enough space to hold `size` number of elements.

Channel

make(chan int, size) // `size` buffer
make(chan int)       // unbuffered

func copy(dst, src []Type) int reference

• As a special case, it also will copy bytes from a string to a slice of bytes.
• The src and dst may overlap.
• Returns the number of elements copied, which will be the minimum of len(src) and len(dst).