D.14.6 mpfr constants

Each of these functions takes a natural number as an argument specifying a precision, and returns a mathematical constant evaluated to that precision.

• const_log2
• pi
• const_catalan
• inf
• ninf
• nan

The name of the constant pi has been shortened from mpfr_const_pi. The functions inf and ninf return infinity and negative infinity, respectively.

The encoding of nan, used to represent the results of undefined computations such as division by zero, is not unique even for a fixed precision. Applications should test for undefined results using nan_p rather than by comparing a result to a hard coded nan (mpfr unary predicates).