D.14.3 mpfr binary operators with a natural operand

Functions with these names take an argument of the form (x,n), where x is an mpfr number and n is a natural number.

• root
• pow_ui
• mul_2ui
• div_2ui
• grow
• shrink

The last two are specific to the virtual code interface, having no counterpart in the native API of the mpfr library. The grow function returns a copy of x with its precision increased by n bits, and the shrink function returns a copy of x with its precision reduced by n bits.

• The precisions are silently capped at the maximum or floored at the minimum allowable precisions if necessary.
• Increasing the precision by the grow function does not directly cause a more accurate result to be computed, but only pads an existing number with zeros.
• Decreasing the precision by the shrink function does not prevent valid bits from being discarded.

The appropriate way to use grow is to grow the precision of an operand before applying an operator to it, which will cause the result to be computed to the full precision. This capability is suitable for algorithms that iterate over increasing precisions until a stopping criterion is met.