This module implements integral arithmetic primitives that check for out-of-range results.

Integral arithmetic operators operate on fixed width types. Results that are not representable in those fixed widths are silently truncated to fit. This module offers integral arithmetic primitives that produce the same results, but set an 'overflow' flag when such truncation occurs. The setting is sticky, meaning that numerous operations can be cascaded and then the flag need only be checked at the end. Whether the operation is signed or unsigned is indicated by an 's' or 'u' suffix, respectively. While this could be achieved without such suffixes by using overloading on the signedness of the types, the suffix makes it clear which is happening without needing to examine the types.

While the generic versions of these functions are computationally expensive relative to the cost of the operation itself, compiler implementations are free to recognize them and generate equivalent and faster code.

- References
- Fast Integer Overflow Checks

- License:
- Boost License 1.0

- Authors:
- Walter Bright

- Source
- core/checkedint.d

- int
**adds**()(int x, int y, ref bool overflow);

long**adds**()(long x, long y, ref bool overflow); -
Add two signed integers, checking for overflow.

The overflow is sticky, meaning a sequence of operations can be done and overflow need only be checked at the end.

- Parameters:
int `x`

left operand int `y`

right operand bool `overflow`

set if an overflow occurs, is not affected otherwise

- Returns:
- the sum

- uint
**addu**()(uint x, uint y, ref bool overflow);

ulong**addu**()(ulong x, ulong y, ref bool overflow); -
Add two unsigned integers, checking for overflow (aka carry).

The overflow is sticky, meaning a sequence of operations can be done and overflow need only be checked at the end.

- Parameters:
uint `x`

left operand uint `y`

right operand bool `overflow`

set if an overflow occurs, is not affected otherwise

- Returns:
- the sum

- int
**subs**()(int x, int y, ref bool overflow);

long**subs**()(long x, long y, ref bool overflow); -
Subtract two signed integers, checking for overflow.

The overflow is sticky, meaning a sequence of operations can be done and overflow need only be checked at the end.

- Parameters:
int `x`

left operand int `y`

right operand bool `overflow`

set if an overflow occurs, is not affected otherwise

- Returns:
- the difference

- uint
**subu**()(uint x, uint y, ref bool overflow);

ulong**subu**()(ulong x, ulong y, ref bool overflow); -
Subtract two unsigned integers, checking for overflow (aka borrow).

- Parameters:
uint `x`

left operand uint `y`

right operand bool `overflow`

set if an overflow occurs, is not affected otherwise

- Returns:
- the difference

- int
**negs**()(int x, ref bool overflow);

long**negs**()(long x, ref bool overflow); -
Negate an integer.

- Parameters:
int `x`

operand bool `overflow`

set if x cannot be negated, is not affected otherwise

- Returns:
- the negation of x

- int
**muls**()(int x, int y, ref bool overflow);

long**muls**()(long x, long y, ref bool overflow); -
Multiply two signed integers, checking for overflow.

- Parameters:
int `x`

left operand int `y`

right operand bool `overflow`

set if an overflow occurs, is not affected otherwise

- Returns:
- the product

- uint
**mulu**()(uint x, uint y, ref bool overflow);

ulong**mulu**()(ulong x, uint y, ref bool overflow);

ulong**mulu**()(ulong x, ulong y, ref bool overflow); -
Multiply two unsigned integers, checking for overflow (aka carry).

- Parameters:
uint `x`

left operand uint `y`

right operand bool `overflow`

set if an overflow occurs, is not affected otherwise

- Returns:
- the product

© 1999–2019 The D Language Foundation

Licensed under the Boost License 1.0.

https://dlang.org/phobos/core_checkedint.html