return 0
	}
	c := cap(b.buf)
	if n <= c/2-m {
		// We can slide things down instead of allocating a new
		// slice. We only need m+n <= c to slide, but
		// we instead let capacity get twice as large so we
		// don't spend all our time copying.
		copy(b.buf, b.buf[b.off:])
	} else if c > maxInt-c-n {
		panic(ErrTooLarge)
	} else {
		// Add b.off to account for b.buf[:b.off] being sliced off the front.

// This may only be set ONCE before use.
func (h *SingleHandler[Req, Resp]) IgnoreNilConn() *SingleHandler[Req, Resp] {
	if h.ignoreNilConn {
		gridLogOnceIf(context.Background(), fmt.Errorf("%s: IgnoreNilConn called twice", h.id.String()), h.id.String()+"IgnoreNilConn")
	}
	h.ignoreNilConn = true
	return h
}

// WithSharedResponse indicates it is unsafe to reuse the response
// when it has been returned on a handler.

        // If the implementation uses identityHashCode(), referential equality is
        // probably intended. So no point in using an equal-but-different factory argument.
        // We check twice to avoid confusion caused by accidental hash collision.
        equalArgs.set(i, shouldBeEqualArg);
      }
    }
    return equalArgs;
  }

  private static boolean hashCodeInsensitiveToArgReference(

then, when you've cleared all the jelly-fish out of the way--'

  `THAT generally takes some time,' interrupted the Gryphon.

  `--you advance twice--'

  `Each with a lobster as a partner!' cried the Gryphon.

  `Of course,' the Mock Turtle said:  `advance twice, set to
partners--'

  `--change lobsters, and retire in same order,' continued the
Gryphon.

    // Add all locations to the scanned set so that in a classpath [jar1, jar2], where jar1 has a
    // manifest with Class-Path pointing to jar2, we won't scan jar2 twice.
    Set<File> scanned = new HashSet<>();
    for (LocationInfo location : locations) {
      scanned.add(location.file());
    }

    // Scan all locations

        // If the implementation uses identityHashCode(), referential equality is
        // probably intended. So no point in using an equal-but-different factory argument.
        // We check twice to avoid confusion caused by accidental hash collision.
        equalArgs.set(i, shouldBeEqualArg);
      }
    }
    return equalArgs;
  }

  private static boolean hashCodeInsensitiveToArgReference(

      //    internal char array (hard to avoid using StringBuilder)
      // 2. we avoid extra copies into temporary buffers altogether
      // The downside is that this will cause us to store the file bytes in memory twice for a short
      // amount of time.
      return new String(ByteSource.this.read(), charset);
    }

    @Override
    public String toString() {

            fail("completeOperation should not throw: " + e.getMessage());
        }
    }

    @Test
    public void test_completeOperation_doubleCall_safe() {
        // Calling completeOperation twice must not throw (idempotent release)
        final AtomicInteger callCount = new AtomicInteger(0);
        final CoordinatorHelper helper = new CoordinatorHelper() {
            @Override

    // benchmarking shows it can take 7 times longer than the other two in some cases. The other two
    // do n swaps, minus a delta (0 or 2 for Reversal, gcd(d, n) for Successive), so that's about
    // twice as many reads and writes. But benchmarking shows that they usually perform better than
    // Dolphin. Reversal is about as good as Successive on average, and it is much simpler,

calling <code>twoprint</code> will call <code>setup</code> exactly
once.
The <code>setup</code> function will complete before either call
of <code>print</code>.
The result will be that <code>"hello, world"</code> will be printed
twice.
</p>

<h3 id="atomic">Atomic Values</h3>

<p>
The APIs in the <a href="/pkg/sync/atomic/"><code>sync/atomic</code></a>
package are collectively “atomic operations”