Does C/C natively include a sign function?

Is the Sign Function a Standard Inclusion in C/C ?

In the pursuit of a function that unequivocally returns -1 for negative numbers and 1 for positive numbers, a natural question arises: does this function exist natively within the C/C standard libraries?

Diving into the Answer

To the initial dismay of programmers, the C/C standard libraries do not explicitly include a "signum" or "sgn" function fulfilling this purpose. However, as the provided solution reveals, a workaround exists using a type-safe C function:

template <typename T> int sgn(T val) {
    return (T(0) < val) - (val < T(0));
}

Advantages of this Approach:

This template function offers several benefits:

• Accurate Signum Implementation: It returns -1, 0, or 1, adhering to the true definition of the signum.
• Versatility: It can be applied to diverse data types, including integers, floats, doubles, unsigned shorts, and custom types.
• Efficient Execution: The template avoids slow copysign calls, optimizing performance through branchless code.
• Standards Compliance: Unlike bit-shifting alternatives, it remains consistent with all bit representations.
• High-Precision Preservation: It maintains the machine's internal high-precision representation, preventing premature rounding errors.

Potential Caveats:

• Compilation Time: As a template, it may take longer to compile in certain contexts.
• Overload Considerations: For unsigned types, the code generates a warning that can be rectified using overloads.

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