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Function core.checkedint.addu
Add two unsigned integers, checking for overflow (aka carry).
uint addu
(
uint x,
uint y,
ref bool overflow
);
ulong addu
(
ulong x,
ulong y,
ref bool overflow
);
The overflow is sticky, meaning a sequence of operations can be done and overflow need only be checked at the end.
Parameters
Name | Description |
---|---|
x | left operand |
y | right operand |
overflow | set if an overflow occurs, is not affected otherwise |
Returns
the sum
Example
bool overflow;
writeln(addu(2, 3, overflow)); // 5
assert(!overflow);
writeln(addu(1, uint .max - 1, overflow)); // uint.max
assert(!overflow);
writeln(addu(uint .min, -1, overflow)); // uint.max
assert(!overflow);
writeln(addu(uint .max, 1, overflow)); // uint.min
assert(overflow);
overflow = false;
writeln(addu(uint .min + 1, -1, overflow)); // uint.min
assert(overflow);
writeln(addu(0, 0, overflow)); // 0
assert(overflow); // sticky
Example
bool overflow;
writeln(addu(2L, 3L, overflow)); // 5
assert(!overflow);
writeln(addu(1, ulong .max - 1, overflow)); // ulong.max
assert(!overflow);
writeln(addu(ulong .min, -1L, overflow)); // ulong.max
assert(!overflow);
writeln(addu(ulong .max, 1, overflow)); // ulong.min
assert(overflow);
overflow = false;
writeln(addu(ulong .min + 1, -1L, overflow)); // ulong.min
assert(overflow);
writeln(addu(0L, 0L, overflow)); // 0
assert(overflow); // sticky
Authors
Walter Bright
License
Copyright © 1999-2022 by the D Language Foundation | Page generated by ddox.