cpp/numeric/math/sqrt

@1-3@ Computes the square root of.

Return value
If no errors occur, square root of, is returned.

If a domain error occurs, an implementation-defined value is returned (NaN where supported).

If a range error occurs due to underflow, the correct result (after rounding) is returned.

Error handling
Errors are reported as specified in math_errhandling.

Domain error occurs if is less than zero.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),
 * If the argument is less than -0, fe_invalid is raised and NaN is returned
 * If the argument is +∞ or ±0, it is returned, unmodified
 * If the argument is NaN, NaN is returned