Function polyline_ffi::decode_polyline_ffi

pub extern fn decode_polyline_ffi(pl: *const c_char,
                                  precision: uint32_t)
                                  -> Array

Convert a Polyline into an array of coordinates

Callers must pass two arguments:

• a pointer to NUL-terminated characters (char*)
• an unsigned 32-bit int for precision (5 for Google Polylines, 6 for OSRM and Valhalla Polylines)

A decoding failure will return an Array whose data field is [[NaN, NaN]], and whose len field is 1.

Implementations calling this function must call drop_float_array with the returned Array, in order to free the memory it allocates.

Safety

This function is unsafe because it accesses a raw pointer which could contain arbitrary data