func cap(v Type) int
The cap built-in function returns the capacity of v, according to its type:
Array: the number of elements in v (same as len(v)).
Pointer to array: the number of elements in *v (same as len(v)).
Slice: the maximum length the slice can reach when resliced;
if v is nil, cap(v) is zero.
Channel: the channel buffer capacity, in units of elements;
if v is nil, cap(v) is zero.
For some arguments, such as a simple array expression, the result can be a constant. See the Go language specification's "Length and capacity" section for details.
func close(c chan<- Type)
The close built-in function closes a channel, which must be either bidirectional or send-only. It should be executed only by the sender, never the receiver, and has the effect of shutting down the channel after the last sent value is received. After the last value has been received from a closed channel c, any receive from c will succeed without blocking, returning the zero value for the channel element. The form
x, ok := <-c
will also set ok to false for a closed and empty channel.
func complex(r, i FloatType) ComplexType
The complex built-in function constructs a complex value from two floating-point values. The real and imaginary parts must be of the same size, either float32 or float64 (or assignable to them), and the return value will be the corresponding complex type (complex64 for float32, complex128 for float64).
func copy(dst, src []Type) int
The copy built-in function copies elements from a source slice into a destination slice. (As a special case, it also will copy bytes from a string to a slice of bytes.) The source and destination may overlap. Copy returns the number of elements copied, which will be the minimum of len(src) and len(dst).
func delete(m map[Type]Type1, key Type)
The delete built-in function deletes the element with the specified key (m[key]) from the map. If m is nil or there is no such element, delete is a no-op.
func imag(c ComplexType) FloatType
The imag built-in function returns the imaginary part of the complex number c. The return value will be floating point type corresponding to the type of c.
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