'Can floats not suport negative or even 0?
It's follow-up question to: How to detect non IEEE-754 float, and how to use them?
In theory, can we assume that c float always support negative numbers?
Solution 1:[1]
Can floats not suport negative or even 0?
I don't think the intention is to allow not supporting negative or zero:
ISO/IEC9899:2017
Characteristics of floating types <float.h>
... The following parameters are used to define the model for each floating-point type:
- s sign (±1)
- b base or radix of exponent representation (an integer > 1)
- e exponent (an integer between a minimum emin and a maximum emax)
- p precision (the number of base-b digits in the significand)
- fk nonnegative integers less than b (the significand digits)
C23 wording adds stronger assertion
ISO/IEC 9899:202x (E)
Floating types shall be able to represent zero (all fk == 0) and all normalized floating-point numbers (f1 > 0 and all possible k digits and e exponents result in values representable in the type
Solution 2:[2]
If you speak about "floating point types" in general (and not about the type named float) when using the word "floats":
Yes:
If you design a compiler, you might define the non-standard type unsigned float with 24 mantissa bits, 8 exponent bits, no sign bit and 256 possible exponent values (instead of 254).
Such a floating point format would only be able to store positive values (not equal to zero) and infinite or NaN would also not be supported.
The advantage of such a format would be a wider range and/or a higher precision than a float data type with the same number of bits.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | eerorika |
| Solution 2 | Martin Rosenau |