5.11.1 Default arguments

Asymptote supports a more flexible mechanism for default function arguments than C++: they may appear anywhere in the function prototype. Because certain data types are implicitly cast to more sophisticated types (see section Casts) one can often avoid ambiguities by ordering function arguments from the simplest to the most complicated. For example, given

real f(int a=1, real b=0) {return a+b;}

then f(1) returns 1.0, but f(1.0) returns 2.0.

The value of a default argument is determined by evaluating the given Asymptote expression in the scope where the called function is defined.