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// RUN: %target-run-simple-swift | %FileCheck %s
// REQUIRES: executable_test
private var backingX = 0
var x: Int {
_read {
print("read: yielding \(backingX).")
yield backingX
backingX += 1
}
_modify {
var temp = backingX
print("modify: current value is \(temp).")
yield &temp
print("modify: incoming value is \(temp).")
if temp >= backingX {
print("modify: accepting.")
backingX = temp
} else {
print("modify: rejecting.")
}
print("modify: resulting value is \(backingX).")
}
}
// CHECK: 0: begin.
print("0: begin.")
// CHECK-NEXT: read: yielding 0.
// CHECK-NEXT: 1: current value of x is 0.
print("1: current value of x is \(x).")
// CHECK-NEXT: read: yielding 1.
// CHECK-NEXT: 2: current value of x is 1.
print("2: current value of x is \(x).")
// CHECK-NEXT: modify: current value is 2.
// CHECK-NEXT: modify: incoming value is -8.
// CHECK-NEXT: modify: rejecting.
// CHECK-NEXT: modify: resulting value is 2.
x -= 10
// CHECK-NEXT: read: yielding 2.
// CHECK-NEXT: 3: current value of x is 2.
print("3: current value of x is \(x).")
// CHECK-NEXT: modify: current value is 3.
// CHECK-NEXT: modify: incoming value is 13.
// CHECK-NEXT: modify: accepting.
// CHECK-NEXT: modify: resulting value is 13.
x += 10
// CHECK-NEXT: read: yielding 13.
// CHECK-NEXT: 4: current value of x is 13.
print("4: current value of x is \(x).")
// CHECK-NEXT: 5: end.
print("5: end.")
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