The patterns used by [ServeMux] allow multiple spaces matching

// it is no longer referenced, so it must be kept alive (see runtime.KeepAlive)
// until any memory allocated from it is no longer needed.
//
// An Arena must never be used concurrently by multiple goroutines.
type Arena struct {
	a unsafe.Pointer
}

// NewArena allocates a new arena.
func NewArena() *Arena {
	return &Arena{a: runtime_arena_newArena()}
}

https://golang.org/doc/articles/c_go_cgo.html.

CFLAGS, CPPFLAGS, CXXFLAGS, FFLAGS and LDFLAGS may be defined with pseudo
#cgo directives within these comments to tweak the behavior of the C, C++
or Fortran compiler. Values defined in multiple directives are concatenated
together. The directive can include a list of build constraints limiting its
effect to systems satisfying one of the constraints

to all its package-level variables followed by calling all <code>init</code>
functions in the order they appear in the source, possibly in multiple files,
as presented to the compiler.
If a package has imports, the imported packages are initialized
before initializing the package itself. If multiple packages import
a package, the imported package will be initialized only once.
The importing of packages, by construction, guarantees that there

	LAX	R7, R8, (R9)          // eb87900000f7
	LAXG	R10, R11, (R12)       // ebbac00000e7
	LAO	R1, R2, (R3)          // eb21300000f6
	LAOG	R4, R5, (R6)          // eb54600000e6

	// load and store multiple
	LMG	n-8(SP), R3, R4         // eb34f0100004
	LMG	-5(R5), R3, R4          // eb345ffbff04
	LMY	n-8(SP), R3, R4         // 9834f010
	LMY	4096(R1), R3, R4        // eb3410000198

	"io"
	"sync"
)

// A Compressor returns a new compressing writer, writing to w.
// The WriteCloser's Close method must be used to flush pending data to w.
// The Compressor itself must be safe to invoke from multiple goroutines
// simultaneously, but each returned writer will be used only by
// one goroutine at a time.
type Compressor func(w io.Writer) (io.WriteCloser, error)

	go run detect.go

which will output something similar to

	export GOIOS_DEV_ID="iPhone Developer: ******@****.*** (XXXXXXXX)"
	export GOIOS_APP_ID=YYYYYYYY.some.bundle.id
	export GOIOS_TEAM_ID=ZZZZZZZZ

If you have multiple devices connected, specify the device UDID with the GOIOS_DEVICE_ID
variable. Use `idevice_id -l` to list all available UDIDs. Then, setting GOARCH to arm64
will select the device:

type fileState interface {
	logicalRemaining() int64
	physicalRemaining() int64
}

// allowedFormats determines which formats can be used.
// The value returned is the logical OR of multiple possible formats.
// If the value is FormatUnknown, then the input Header cannot be encoded
// and an error is returned explaining why.
//
// As a by-product of checking the fields, this function returns paxHdrs, which

// license that can be found in the LICENSE file.

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "_cgo_export.h"

/* Test calling a Go function with multiple return values.  */

void
callMulti(void)
{
	struct multi_return result = multi();
	assert(strcmp(result.r0, "multi") == 0);
	assert(result.r1 == 0);
	free(result.r0);

//go:build ignore

// Compute Fibonacci numbers with two goroutines
// that pass integers back and forth.  No actual
// concurrency, just threads and synchronization
// and foreign code on multiple pthreads.

package main

import (
	big "."
	"runtime"
)

func fibber(c chan *big.Int, out chan string, n int64) {
	// Keep the fibbers in dedicated operating system