Modern Math NegWrapping

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NegWrapping

Negates an integer within its type, so the most negative value stays as it is.

Syntax

NegWrapping( byval a as T ) as T

Notes

• Wraps within the type: negating the most negative value returns it unchanged. Note this is NOT what the bare -a does on a narrow type -- that promotes to an integer first and can answer with a value that no longer fits.
• It exists so that deliberate wrapping can be spelled as deliberate.
• NegChecked reports the case and NegSaturating clamps it.

Examples

#import "std/numeric"
using numeric

dim as int8 worst = -128
print NegWrapping( worst )   '' -128 -- wrapped back to itself

'' NOT identical to the bare operator, which PROMOTES to an integer and
'' so answers 128 -- a value that no longer fits in a BYTE. This one
'' stays in the type and wraps, which is what a checksum or ring index
'' wants.
print -worst                 '' 128

dim as int8 ordinary = 100
print NegWrapping( ordinary )                 '' -100

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Library: Math Library
Category: Math Library
Documented under: Members