safeOp.mulPow2

Equivalent to left * pow(2, exp), but faster and works with a wider range of inputs. This is a safer alternative to left << exp that is still very fast.

Note that (conceptually) rounding occurs after the *, meaning that mulPow2(left, -exp) is equivalent to divPow2(left, exp).

auto mulPow2(N left, M exp)
template safeOp(IntFlagPolicy policy)
pure @safe nothrow @nogc
auto
mulPow2
(
N
M
)
(
const N left
,
const M exp
)
if (
(
isFloatingPoint!N &&
isScalarType!M
) ||
(
isScalarType!N &&
isFloatingPoint!M
)
)
auto mulPow2(N left, M exp)

Examples

import checkedint.sticky : safeOp; // use IntFlagPolicy.sticky

assert(safeOp.mulPow2(-23, 5) == -736);
safeOp.mulPow2(10_000_000, 10);
assert(IntFlags.local.clear() == IntFlag.posOver);

assert(safeOp.mulPow2(65536, -8) == 256);
assert(safeOp.mulPow2(-100, -100) == 0);

safeOp.mulPow2

Examples

Meta

Source