class_docstr: Holds the ops for each dtypes signature like ('ff->f', func1)
  and allows to do look ups for these
code: def _process_signatures(self, signatures):
      ops = []
      for sig in signatures:
          if isinstance(sig, tuple):
              sig, op = sig
          else:
              op = self._default_func
          ins, outs = self._sig_str_to_tuple(sig)
          # Check the number of inputs and outputs matches the gufunc sig
          if len(ins) != self._nin:
              raise ValueError(
                  f"signature {sig} for dtypes is invalid number of inputs "
                  "is not consistent with general signature"
              )
          if len(outs) != self._nout:
              raise ValueError(
                  f"signature {sig} for dtypes is invalid number of inputs "
                  "is not consistent with general signature"
              )
  
          ops.append(_OpsRegister._Op(ins, outs, op))
      return ops
  
imports: import re
  import numpy
  import cupy
  import cupy._core._routines_manipulation
  from cupy._core._dtype import get_dtype, _raise_if_invalid_cast
  from cupy._core import internal
label_desc: Use image node_id 3 for calling the _OpsRegister obj's underlying member method code with example usage: obj._process_signatures(signatures) and returns: ops